CMP Journal 2025-07-02
Statistics
Nature: 25
Nature Materials: 1
Nature Physics: 1
Physical Review Letters: 15
Physical Review X: 2
arXiv: 78
Nature
Boron-mediated modular assembly of tetrasubstituted alkenes
Original Paper | Synthetic chemistry methodology | 2025-07-01 20:00 EDT
Liang Wei, Mihai V. Popescu, Adam Noble, Robert S. Paton, Varinder K. Aggarwal
Alkenes are a central part of organic chemistry1,2,3. However, although most alkenes are easy to prepare, the controlled synthesis of tetrasubstituted alkenes, those with four groups around the central C=C bond, remains challenging1,2,3,4,5. Here we report the boron-mediated assembly of tetrasubstituted alkenes with complete control of the double-bond geometry. The migrating group and electrophile add syn across the alkyne. Mild oxidation leads to intermediate borinic esters6, which can be isolated and purified or reacted directly in a range of transformations, including cross-couplings and homologation reactions. In particular, subjecting the intermediate borinic esters to Zweifel7,8 olefination conditions can give either retention or inversion of the double-bond geometry, depending on whether base is present or not. Different positional and stereoisomers of the tetrasubstituted alkenes can be easily accessed, highlighting the breadth and versatility of the method. This was showcased through its successful application to the rapid synthesis of drug molecules and natural products with high yield and stereocontrol. Not only does this method provide efficient access to the long-standing challenge of the stereocontrolled synthesis of tetrasubstituted alkenes but it also introduces new concepts related to the intervention of non-classical borenium ions in the Zweifel olefination.
Synthetic chemistry methodology, Natural product synthesis
Stereodivergent transformation of a natural polyester to enantiopure PHAs
Original Paper | Synthetic chemistry methodology | 2025-07-01 20:00 EDT
Jun-Jie Tian, Ruirui Li, Ethan C. Quinn, Jiyun Nam, Eswara Rao Chokkapu, Zhen Zhang, Li Zhou, Ravikumar R. Gowda, Eugene Y.-X. Chen
Natural chiral polymers, such as DNA, proteins, cellulose and poly[(R)-3-hydroxybutyrate] ((R)-P3HB), are prevalent in their enantiopure forms1,2. Existing methods to synthesize enantiopure polymers focus on enantiospecific polymerization, in which only one specific enantiomer is obtained from the corresponding chiral monomer3,4,5,6. Here we introduce a catalytic stereodivergent synthetic strategy to access all enantiopure di-isotactic poly(3-hydroxyalkanoate) (PHA) diastereomers from bacterial (R)-P3HB as the single chiral source. A series of enantiopure (R,R)-α-alkylated-β-butyrolactones are obtained from (R)-P3HB and then subjected to the catalyst-controlled diastereodivergent ring-opening polymerization (ROP) to enantiopure di-isotactic α-alkylated PHAs. Metal-catalysed coordination-insertion ROP results in threo-(R,R)-di-isotactic PHAs with chiral retention, whereas anionic ROP catalysed by an organic superbase produces erythro-(R,S)-di-isotactic PHAs with chiral inversion, achieving precision di-isotactic PHAs with exclusive regio- and stereoregularity. This strategy has also enabled the stereodivergent synthesis of all four [(R,R), (S,S), (R,S) and (S,R)] stereoisomers of α,α-dialkylated PHAs from (R)-P3HB, which can be depolymerized to chiral α,α-dialkylated-β-butyrolactones with high stereoselectivity. Overall, this catalyst-controlled regio- and stereoselective, stereodivergent synthetic methodology provides access to 16 enantiopure stereoisomers of α(α)-(di)substituted PHAs and enables the stereochemistry-defined structure-property relationship study of the di-isotactic PHAs, providing insights into the effects of main-chain stereoconfigurations and alkyl side chains on their thermal properties, melt processability, mechanical performance and supramolecular stereocomplexation.
Synthetic chemistry methodology, Polymer synthesis
Mapping the adaptive landscape of Batesian mimicry using 3D-printed stimuli
Original Paper | Animal behaviour | 2025-07-01 20:00 EDT
Christopher H. Taylor, David James George Watson, John Skelhorn, Danny Bell, Simon Burdett, Aoife Codyre, Kathryn Cooley, James R. Davies, Joshua Joseph Dawson, Tahiré D’Cruz, Samir Raj Gandhi, Hannah J. Jackson, Rebecca Lowe, Elizabeth Ogilvie, Alexandra Lei Pond, Hallie Rees, Joseph Richardson, Joshua Sains, Francis Short, Christopher Brignell, Gabrielle L. Davidson, Hannah M. Rowland, Mark East, Ruth Goodridge, Francis Gilbert, Tom Reader
In a classic example of adaptation, harmless Batesian mimics gain protection from predators through resemblance to one or more unpalatable models1,2. Mimics vary greatly in accuracy, and explaining the persistence of inaccurate mimics is an ongoing challenge for evolutionary biologists3,4. Empirical testing of existing hypotheses is constrained by the difficulty of assessing the fitness of phenotypes absent among extant species, leaving large parts of the adaptive landscape unexplored5–a problem affecting the study of the evolution of most complex traits. Here, to address this, we created mimetic phenotypes that occupy hypothetical areas of trait space by morphing between 3D images of real insects (flies and wasps), and tested the responses of real predators to high-resolution, full-colour 3D-printed reproductions of these phenotypes. We found that birds have an excellent ability to learn to discriminate among insects on the basis of subtle differences in appearance, but this ability is weaker for pattern and shape than for colour and size traits. We found that mimics gained no special protection from intermediate resemblance to multiple model phenotypes. However, discrimination ability was lower in some invertebrate predators (especially crab spiders and mantises), highlighting that the predator community is key to explaining the apparent inaccuracy of many mimics.
Animal behaviour, Batesian mimicry, Evolutionary ecology
Functional amyloid proteins confer defence against predatory bacteria
Original Paper | Bacteria | 2025-07-01 20:00 EDT
Hannah E. Ledvina, Ryan Sayegh, Ricardo O. Carale, A. Maxwell Burroughs, Alexa R. Macklin, Ashley L. Azadeh, Layla D. Borja Najera, L. Aravind, Aaron T. Whiteley
Bdellovibrio bacteriovorus is a predatory bacterium that non-selectively preys on Gram-negative bacteria by invading the prey-cell periplasm, leaching host nutrients and ultimately lysing the infected cell to exit and find a new host1,2. The predatory life cycle of B. bacteriovorus is, in many ways, comparable to a bacteriophage. However, unlike phage defence, defence against B. bacteriovorus has not been widely investigated. Here we screened a collection of diverse Escherichia coli strains for resistance to B. bacteriovorus and identified that roughly one-third of strains robustly defended against predation by producing curli fibres. Curli fibres are oligomers of the functional amyloid protein CsgA, which is exceptionally durable3. Using genetics and microscopy, we demonstrate that curli fibres provide a barrier that protects susceptible cells independent of genes required for biofilm formation. This barrier further protected E. coli against attack by the predatory bacterium Myxococcus xanthus and select phages. Bioinformatic analysis of bacterial amyloids showed these systems are diverse and widespread in diderm bacteria (those with both inner and outer membranes). One of these, an evolutionarily distinct amyloid encoded by Pseudomonas aeruginosa, also protected against B. bacteriovorus. This work establishes that functional amyloids defend bacteria against a wide range of threats.
Bacteria, Bacteriology
Plants monitor the integrity of their barrier by sensing gas diffusion
Original Paper | Cell fate | 2025-07-01 20:00 EDT
Hiroyuki Iida, Isidro Abreu, Jennifer López Ortiz, Lucas León Peralta Ogorek, Vinay Shukla, Meeri Mäkelä, Munan Lyu, Alexey Shapiguzov, Francesco Licausi, Ari Pekka Mähönen
Barrier tissues isolate organisms from their surrounding environment. Maintaining the integrity of the tissues is essential for this function. In many seed plants, periderm forms as the outer barrier during secondary growth to prevent water loss and pathogen infection1. The periderm is regenerated when its integrity is lost following injury; however, the underlying mechanism remains largely unknown, despite its importance for plant survival. Here we report that periderm integrity in Arabidopsis roots is sensed by diffusion of the gases ethylene and oxygen. Following injury of the periderm, ethylene leaks out through the wound and oxygen enters, resulting in attenuation of ethylene signalling and hypoxia signalling. This condition promotes periderm regeneration in the root. When regeneration is complete and barrier integrity is re-established, pre-injury levels of ethylene and hypoxia signalling are regained. Gas diffusion monitoring is also used to re-establish the barrier in inflorescence stems after the epidermis is injured. We thus propose that gas diffusion is used by plants as a general principle to monitor and re-establish barrier integrity.
Cell fate, Plant hormones, Plant regeneration, Wounding
A mouse brain stereotaxic topographic atlas with isotropic 1-μm resolution
Original Paper | Computational neuroscience | 2025-07-01 20:00 EDT
Zhao Feng, Xiangning Li, Yue Luo, Xin Liu, Ben Long, Tao Jiang, Xueyan Jia, Xiaowei Chen, Jie Luo, Xiaokang Chai, Zhen Wang, Miao Ren, Xin Lu, Gang Yao, Mengting Zhao, Yuxin Li, Zhixiang Liu, Hong Ni, Chuhao Dou, Shengda Bao, Shicheng Yang, Zoutao Zhang, Jiandong Zhou, Lingyi Cai, Qi Zhang, Ayizuohere Tudi, Chaozhen Tan, Zhengchao Xu, Siqi Chen, Wenxiang Ding, Wenjuan Shi, Anan Li, Hong-wei Dong, Hui Gong, Qingming Luo
Multi-omics studies, represented by connectomes and spatial transcriptomes, have entered the era of single-cell resolution, necessitating a reference brain atlas with spatial localization capability at the single-cell level1,2,3,4. However, such atlases are unavailable5. Here we present a whole mouse brain dataset of Nissl-based cytoarchitecture with isotropic 1-μm resolution, achieved through continuous micro-optical sectioning tomography. By integrating multi-modal images, we constructed a three-dimensional reference atlas of the mouse brain, providing the three-dimensional topographies of 916 structures and enabling arbitrary-angle slice image generation at 1-μm resolution. We developed an informatics-based platform for visualizing and sharing of the atlas images, offering services such as brain slice registration, neuronal circuit mapping and intelligent stereotaxic surgery planning. This atlas is interoperable with widely used stereotaxic atlases, supporting cross-atlas navigation of corresponding coronal planes in two dimensions and spatial mapping across atlas spaces in three dimensions. By facilitating the data analysis and visualization for large brain mapping projects, our atlas promises to be a versatile brainsmatics tool for studying the whole brain at single-cell level.
Computational neuroscience, Data integration, Standards
Whole-genome ancestry of an Old Kingdom Egyptian
Original Paper | Anthropology | 2025-07-01 20:00 EDT
Adeline Morez Jacobs, Joel D. Irish, Ashley Cooke, Kyriaki Anastasiadou, Christopher Barrington, Alexandre Gilardet, Monica Kelly, Marina Silva, Leo Speidel, Frankie Tait, Mia Williams, Nicolas Brucato, Francois-Xavier Ricaut, Caroline Wilkinson, Richard Madgwick, Emily Holt, Alexandra J. Nederbragt, Edward Inglis, Mateja Hajdinjak, Pontus Skoglund, Linus Girdland-Flink
Ancient Egyptian society flourished for millennia, reaching its peak during the Dynastic Period (approximately 3150-30 bce). However, owing to poor DNA preservation, questions about regional interconnectivity over time have not been addressed because whole-genome sequencing has not yet been possible. Here we sequenced a 2× coverage whole genome from an adult male Egyptian excavated at Nuwayrat (Nuerat, نويرات). Radiocarbon dated to 2855-2570 cal. bce, he lived a few centuries after Egyptian unification, bridging the Early Dynastic and Old Kingdom periods. The body was interred in a ceramic pot within a rock-cut tomb1, potentially contributing to the DNA preservation. Most of his genome is best represented by North African Neolithic ancestry, among available sources at present. Yet approximately 20% of his genetic ancestry can be traced to genomes representing the eastern Fertile Crescent, including Mesopotamia and surrounding regions. This genetic affinity is similar to the ancestry appearing in Anatolia and the Levant during the Neolithic and Bronze Age2,3,4,5. Although more genomes are needed to fully understand the genomic diversity of early Egyptians, our results indicate that contacts between Egypt and the eastern Fertile Crescent were not limited to objects and imagery (such as domesticated animals and plants, as well as writing systems)6,7,8,9 but also encompassed human migration.
Anthropology, Archaeology, Evolutionary genetics, Population genetics
The mutagenic forces shaping the genomes of lung cancer in never smokers
Original Paper | Cancer genomics | 2025-07-01 20:00 EDT
Marcos Díaz-Gay, Tongwu Zhang, Phuc H. Hoang, Charles Leduc, Marina K. Baine, William D. Travis, Lynette M. Sholl, Philippe Joubert, Azhar Khandekar, Wei Zhao, Christopher D. Steele, Burçak Otlu, Shuvro P. Nandi, Raviteja Vangara, Erik N. Bergstrom, Mariya Kazachkova, Oriol Pich, Charles Swanton, Chao Agnes Hsiung, I-Shou Chang, Maria Pik Wong, Kin Chung Leung, Jian Sang, John P. McElderry, Caleb Hartman, Frank J. Colón-Matos, Mona Miraftab, Monjoy Saha, Olivia W. Lee, Kristine M. Jones, Pilar Gallego-García, Yang Yang, Xiaoming Zhong, Eric S. Edell, Jacobo Martínez Santamaría, Matthew B. Schabath, Sai S. Yendamuri, Marta Manczuk, Jolanta Lissowska, Beata Świątkowska, Anush Mukeria, Oxana Shangina, David Zaridze, Ivana Holcatova, Dana Mates, Sasa Milosavljevic, Millica Kontic, Yohan Bossé, Bonnie E. Gould Rothberg, David C. Christiani, Valerie Gaborieau, Paul Brennan, Geoffrey Liu, Paul Hofman, Lixing Yang, Martin A. Nowak, Jianxin Shi, Nathaniel Rothman, David C. Wedge, Robert Homer, Soo-Ryum Yang, Angela C. Pesatori, Dario Consonni, Qing Lan, Bin Zhu, Stephen J. Chanock, Jiyeon Choi, Ludmil B. Alexandrov, Maria Teresa Landi
Lung cancer in never smokers (LCINS) accounts for around 25% of all lung cancers1,2 and has been associated with exposure to second-hand tobacco smoke and air pollution in observational studies3,4,5. Here we use data from the Sherlock-Lung study to evaluate mutagenic exposures in LCINS by examining the cancer genomes of 871 treatment-naive individuals with lung cancer who had never smoked, from 28 geographical locations. KRAS mutations were 3.8 times more common in adenocarcinomas of never smokers from North America and Europe than in those from East Asia, whereas a higher prevalence of EGFR and TP53 mutations was observed in adenocarcinomas of never smokers from East Asia. Signature SBS40a, with unknown cause6, contributed the largest proportion of single base substitutions in adenocarcinomas, and was enriched in cases with EGFR mutations. Signature SBS22a, which is associated with exposure to aristolochic acid7,8, was observed almost exclusively in patients from Taiwan. Exposure to secondhand smoke was not associated with individual driver mutations or mutational signatures. By contrast, patients from regions with high levels of air pollution were more likely to have TP53 mutations and shorter telomeres. They also exhibited an increase in most types of mutations, including a 3.9-fold increase in signature SBS4, which has previously been linked with tobacco smoking9, and a 76% increase in the clock-like10 signature SBS5. A positive dose-response effect was observed with air-pollution levels, correlating with both a decrease in telomere length and an increase in somatic mutations, mainly attributed to signatures SBS4 and SBS5. Our results elucidate the diversity of mutational processes shaping the genomic landscape of lung cancer in never smokers.
Cancer genomics, Lung cancer
The Somatic Mosaicism across Human Tissues Network
Review Paper | Genome | 2025-07-01 20:00 EDT
Tim H. H. Coorens, Ji Won Oh, Yujin Angelina Choi, Nam Seop Lim, Boxun Zhao, Adam Voshall, Alexej Abyzov, Lucinda Antonacci-Fulton, Samuel Aparicio, Kristin G. Ardlie, Thomas J. Bell, James T. Bennett, Bradley E. Bernstein, Thomas G. Blanchard, Alan P. Boyle, Jason D. Buenrostro, Kathleen H. Burns, Fei Chen, Rui Chen, Sangita Choudhury, Harsha V. Doddapaneni, Evan E. Eichler, Gilad D. Evrony, Melissa A. Faith, Thomas G. Fazzio, Robert S. Fulton, Manuel Garber, Nils Gehlenborg, Soren Germer, Gad Getz, Richard A. Gibbs, Raquel G. Hernandez, Fulai Jin, Jan O. Korbel, Dan A. Landau, Heather A. Lawson, Niall J. Lennon, Heng Li, Yan Li, Po-Ru Loh, Gabor Marth, Michael J. McConnell, Ryan E. Mills, Stephen B. Montgomery, Pradeep Natarajan, Peter J. Park, Rahul Satija, Fritz J. Sedlazeck, Diane D. Shao, Hui Shen, Andrew B. Stergachis, Hunter R. Underhill, Alexander E. Urban, Melissa W. VonDran, Christopher A. Walsh, Ting Wang, Tao P. Wu, Chenghang Zong, Eunjung Alice Lee, Flora M. Vaccarino, Richard S. Conroy, Brionna Y. Hair, Walter J. Koroshetz, Roger Little, Amy C. Lossie, Jill A. Morris, Dena C. Procaccini, Wendy Wang, Casey Andrews, Sarah Cody, Milinn Kremitzki, Daofeng Li, Tina Lindsay, Wenjin Zhang, Valerie J. Estela-Pro, Kayla Giancarlo, Melissa Grimm, Azra Hasan, M. Kathryn Leonard, Phoebe McDermott, Mary Pfeiffer, Isabel Sleeman, Stephanie Bohaczuk, Colleen P. Davis, Christian D. Frazar, Kendra Hoekzema, Meng-Fan Huang, Caitlin Jacques, Dana M. Jensen, J. Thomas Kolar, Youngjun Kwon, Kelsey Loy, Yizi Mao, Min-Hwan Sohn, Katherine M. Munson, Shane Neph, Jeffrey Ou, Nancy L. Parmalee, Meranda M. Pham, Jane Ranchalis, Luyao Ren, Adriana E. Sedeño-Cortés, Joshua D. Smith, Melanie Sorensen, Lila Sutherlin, Mitchell R. Vollger, Chia-Lin Wei, Jeffrey M. Weiss, Christina Zakarian, Natalie Y. T. Au, Amy Leonardson, Jiadong Lin, Taralynn Mack, Sean R. McGee, Anna Minkina, Patrick M. Nielsen, Chris Oliveira, Erica Ryke, Tristan Shaffer, Elliott G. Swanson, Elizabeth G. Atkinson, Sravya Bhamidipati, Hsu Chao, Christopher M. Grochowski, Harsha V. Doddapaneni, Divya Kalra, Ziad Khan, Kavya Kottapalli, Marie-Claude Gingras, Walker Hale, Heer Mehta, Donna M. Muzny, Muchun Niu, Luis F. Paulin, Jeffrey Rogers, Evette Scott, Fritz J. Sedlazeck, Kimberly Walker, Tao Wu, Kristin G. Ardlie, Viktor Adalsteinsson, Lisa Anderson, Carrie Cibulskis, Laura Domènech, Kiran Garimella, Whitney Hornsby, Steve Huang, Satoshi Koyama, Niall J. Lennon, Tetsushi Nakao, Azeet Narayan, Evin Padhi, Constantijn Scharlee, Md Mesbah Uddin, Liying Xue, Zhi Yu, Shadi Zaheri, Ruolin Liu, Ning Stella Li, Hang Su, Derek Albracht, Eddie Belter, Emma Casey, Justin Chen, Yuchen Cheng, Shihua Dong, Qichen Fu, Robert Fulton, John Garza, H. Josh Jang, Sheng Chih Jin, Benjamin K. Johnson, Nahyun Kong, Daofeng Li, Zefan Li, Shane Liu, Juan F. Macias-Velasco, Elvisa Mehinovic, Benpeng Miao, Theron Palmer, Purva Patel, Mary F. Majewski, Daniel C. Rohrer, Andrew Ruttenberg, Ayush Semwal, Jiawei Shen, Zitian Tang, Chad Tomlinson, Wenjin Zhang, Zilan Xin, Christina Missler, Brianne E. Livermore, Jade E. B. Carter, William Driscoll, Uday S. Evani, Heather Geiger, M. Tausif Hasan, Manisha Kher, Rajeeva Musunuri, Giuseppe Narzisi, Nicolas Robine, Alexi Runnels, Mingyun Bae, Michele Berselli, Ann Caplin, Hye-Jung Elizabeth Chun, Niklas L. Engel, William C. Feng, Yan Gao, Dominik Glodzik, Yoo-Jin Jiny Ha, Hu Jin, Sehi L’Yi, Lovelace J. Luquette, Maximilian Marin, Julia Markowski, Dominika Maziec, Huang Neng, Sarah Nicholson, Junseok Park, Qin Qian, Han Qu, Douglas Rioux, William Ronchetti, Andrew Schroeder, Corinne E. Sexton, Yichen Si, Kar-Tong Tan, David Tang, Alexander D. Veit, Vinayak V. Viswanadham, Suenghyun Wang, Kyung Ah Woo, Xi Zeng, Yuwei Zhang, Yifan Zhao, Ying Zhou, Michail Andreopoulos, Shannon Ehmsen, Cesar Ferreyra-Mansilla, Clara TaeHee Kim, David Michaels, Bianca Morris, Brandt A. Bessell, Ingrid Flashpohler, Steve Losh, Torrin L. McDonald, Camille Mumm, Jessica A. Switzenberg, Jinhao Wang, Weichen Zhou, Guanlan Dong, Nazia Hilal, Se-Young Jo, Shayna L. Mallett, Monica Devi Manam, Shulin Mao, Christopher Walsh, Sijing Zhao, Yiling Elaine Huang, Abhiram Natu, Reenal Pattni, Carolin Purman, Bo Zhou, Xiaowei Zhu, Jiayi Luo, Yichi Niu, Rohan Thakur, David A. Weitz, Yang Zhang, Yilei Fu, Michal B. Izydorczyk, Luis F. Paulin, Xiaomei Zhan, Xinchang Zheng, Geon Hue Bae, Taejeong Bae, Areum Cho, June Hyug Choi, Hyungbin Chun, Mrunal Dehankar, Yeongjun Jang, Seok-Won Jeong, Min Ji, Mee Sook Jun, Su Rim Kim, Seong Gyu Kwon, Soung-Hoon Lee, Nanda Maya Mali, Arijit Panda, Jung Min Park, JaeEun Shin, Milovan Suvakov, Gabor T. Marth, Brad Demarest, Stephanie Gardiner, Stephanie J. Georges, Yingqi Zhang, Sammantha Avaylon, Alexandre Pellan Cheng, Wei-Yu Chi, Mariela Cortés-López, Andrew R. D’Avino, Husain Danish, Elliot Eton, Foteini Fotopoulo, Saravanan Ganesan, Yiyun Lin, Qing Luo, Levan Mekerishvili, Joe Pelt, Catherine Potenski, Tamara Prieto, Jake Qiu, Ivan Raimondi, Mandeep Singh, Dennis Yuan, John Zinno, Benjamin Costa, Jonathan Evan Shoag, Jimin Tan, Aristotelis Tsirigos, Nisrine T. Jabara, Marta Grońska-Pęski, Emre Caglayan, Hayley Cline, Niklas L. Engel, Shelbi E. Gill, Robert Sean Hill, Andrea J. Kriz, Julia Markowski, Alisa Mo, Daniel Snellings, Justin S. Becker, Aidan H. Burn, Wen-Chih Cheng, Jennifer A. Karlow, Cheuk-Ting Law, Shayna L. Mallet, Carlos Mendez-Dorantes, Khue H. Nguyen, Adam Voshall, Boxun Zhao, Benno Orr, Andrew J. C. Russell, He Li, Yan Li, Leina Lu, Xiaofeng Zhu, Trishita Basak, Azita Ghodssi, Katrina Newcomer, Yuqing Wang
From fertilization onwards, the cells of the human body acquire variations in their DNA sequence, known as somatic mutations. These postzygotic mutations arise from intrinsic errors in DNA replication and repair, as well as from exposure to mutagens. Somatic mutations have been implicated in some diseases, but a fundamental understanding of the frequency, type and patterns of mutations across healthy human tissues has been limited. This is primarily due to the small proportion of cells harbouring specific somatic variants within an individual, making them more challenging to detect than inherited variants. Here we describe the Somatic Mosaicism across Human Tissues Network, which aims to create a reference catalogue of somatic mutations and their clonal patterns across 19 different tissue sites from 150 non-diseased donors and develop new technologies and computational tools to detect somatic mutations and assess their phenotypic consequences, including clonal expansions. This strategy enables a comprehensive examination of the mutational landscape across the human body, and provides a comparison baseline for somatic mutation in diseases. This will lead to a deep understanding of somatic mutations and clonal expansions across the lifespan, as well as their roles in health, in ageing and, by comparison, in diseases.
Genome, Genomics, Mutation
Mapping and engineering RNA-driven architecture of the multiphase nucleolus
Original Paper | Biopolymers in vivo | 2025-07-01 20:00 EDT
Sofia A. Quinodoz, Lifei Jiang, Aya A. Abu-Alfa, Troy J. Comi, Hongbo Zhao, Qiwei Yu, Lennard W. Wiesner, Jordy F. Botello, Anita Donlic, Elizabeth Soehalim, Prashant Bhat, Christiane Zorbas, Ludivine Wacheul, Andrej Košmrlj, Denis L. J. Lafontaine, Sebastian Klinge, Clifford P. Brangwynne
Biomolecular condensates are key features of intracellular compartmentalization1,2. As the most prominent nuclear condensate in eukaryotes, the nucleolus is a multiphase liquid-like structure in which ribosomal RNAs (rRNAs) are transcribed and processed, undergoing multiple maturation steps to form the small (SSU) and large (LSU) ribosomal subunits3,4,5. However, how rRNA processing is coupled to the layered organization of the nucleolus is poorly understood owing to a lack of tools to precisely monitor and perturb nucleolar rRNA processing dynamics. Here we developed two complementary approaches to spatiotemporally map rRNA processing and engineer de novo nucleoli. Using sequencing in parallel with imaging, we found that rRNA processing steps are spatially segregated, with sequential maturation of rRNA required for its outward movement through nucleolar phases. By generating synthetic nucleoli in cells using an engineered rDNA plasmid system, we show that defects in SSU processing can alter the ordering of nucleolar phases, resulting in inside-out nucleoli and preventing rRNA outflux, while LSU precursors are necessary to build the outermost layer of the nucleolus. These findings demonstrate how rRNA is both a scaffold and substrate for the nucleolus, with rRNA acting as a programmable blueprint for the multiphase architecture that facilitates assembly of an essential molecular machine.
Biopolymers in vivo, Organelles
Trade-offs in aviation impacts on climate favour non-CO2 mitigation
Original Paper | Aerospace engineering | 2025-07-01 20:00 EDT
Michael J. Prather, Andrew Gettelman, Joyce E. Penner
Climate assessments of civil aviation1,2 have consistently quantified the dominant climate-forcing components: (1) CO2 emissions, (2) NOx (NO + NO2) emissions and (3) persistent contrails. All three components exert a positive radiative forcing (RF) and lead to climate warming of similar magnitudes. The aviation community is actively seeking to reduce its climate footprint through advanced engine technologies, more sustainable aviation fuel and optimal routing plans3,4,5,6,7,8,9,10,11,12. These approaches usually involve a trade-off of CO2 against NOx or contrails (non-CO2), such as burning 1% more fuel to decrease contrail RF by 4%. Here, we show that a climate-trade-off risk curve derived from uncertainties in the RF components2,13,14,15,16 can give the probability that a specified trade-off ratio will produce a climate benefit. For each component, we calculate the integrated effective RF resulting from 1 year of flights: global warming per activity (GWA). The complementary cumulative probability distribution of the GWA(non-CO2) to GWA(CO2) ratio results in a climate-trade-off risk curve giving the likelihood of a positive climate outcome as a function of the trade-off-CO2 to trade-off-non-CO2 ratio, because the product, GWA × trade-off, should be the same for both. We find a likely (67%) chance of climate mitigation on a 100-year time horizon for the above suggested ratio of 1:4, favouring proposed non-CO2 mitigation efforts3,4,5,6,7,8,9,10,11,12 with ratios smaller than this.
Aerospace engineering, Climate-change impacts
Energy-speed relationship of quantum particles challenges Bohmian mechanics
Original Paper | Quantum mechanics | 2025-07-01 20:00 EDT
Violetta Sharoglazova, Marius Puplauskis, Charlie Mattschas, Chris Toebes, Jan Klaers
Classical mechanics characterizes the kinetic energy of a particle, the energy it holds due to its motion, as consistently positive. By contrast, quantum mechanics describes the motion of particles using wave functions, in which regions of negative local kinetic energy can emerge1. This phenomenon occurs when the amplitude of the wave function experiences notable decay, typically associated with quantum tunnelling. Here, we investigate the quantum mechanical motion of particles in a system of two coupled waveguides, in which the population transfer between the waveguides acts as a clock, allowing particle speeds along the waveguide axis to be determined. By applying this scheme to exponentially decaying quantum states at a reflective potential step, we determine an energy-speed relationship for particles with negative local kinetic energy. We find that the smaller the energy of the particles–in other words, the more negative the local kinetic energy–the higher the measured speed inside the potential step. Our findings contribute to the ongoing tunnelling time debate2,3,4,5,6 and can be viewed as a test of Bohmian trajectories in quantum mechanics<a data-test=”citation-ref” data-track=”click” data-track-action=”reference anchor” data-track-label=”link” href=”https://www.nature.com/articles/s41586-025-09099-4#ref-CR7“ id=”ref-link-section-d183126717e352” title=”Bohm, D. A suggested interpretation of the quantum theory in terms of “hidden” variables. Phys. Rev. 85, 166-179 (1952).”>7,8,9. Regarding the latter, we find that the measured energy-speed relationship does not align with the particle dynamics postulated by the guiding equation in Bohmian mechanics.
Quantum mechanics, Quantum optics
Range extender mediates long-distance enhancer activity
Original Paper | Development | 2025-07-01 20:00 EDT
Grace Bower, Ethan W. Hollingsworth, Sandra H. Jacinto, Joshua A. Alcantara, Benjamin Clock, Kaitlyn Cao, Mandy Liu, Adam Dziulko, Ana Alcaina-Caro, Qianlan Xu, Dorota Skowronska-Krawczyk, Javier Lopez-Rios, Diane E. Dickel, Anaïs F. Bardet, Len A. Pennacchio, Axel Visel, Evgeny Z. Kvon
Although most mammalian transcriptional enhancers regulate their cognate promoters over distances of tens of kilobases, some enhancers act over distances in the megabase range1. The sequence features that enable such long-distance enhancer-promoter interactions remain unclear. Here we used in vivo enhancer-replacement experiments at the mouse Shh locus to show that short- and medium-range limb enhancers cannot initiate gene expression at long-distance range. We identify a cis-acting element, range extender (REX), that confers long-distance regulatory activity and is located next to a long-range limb enhancer of Sall1. The REX element has no endogenous enhancer activity. However, addition of the REX to other short- and mid-range limb enhancers substantially increases their genomic interaction range. In the most extreme example observed, addition of REX increased the range of an enhancer by an order of magnitude from its native 73 kb to 848 kb. The REX element contains highly conserved [C/T]AATTA homeodomain motifs that are critical for its activity. These motifs are enriched in long-range limb enhancers genome-wide, including the ZRS (zone of polarizing activity (ZPA) regulatory sequence), a benchmark long-range limb enhancer of Shh2. The ZRS enhancer with mutated [C/T]AATTA motifs maintains limb activity at short range, but loses its long-range activity, resulting in severe limb reduction in knock-in mice. In summary, we identify a sequence signature associated with long-range enhancer-promoter interactions and describe a prototypical REX element that is necessary and sufficient to confer long-distance activation by remote enhancers.
Development, Gene regulation
Ancient DNA reveals the prehistory of the Uralic and Yeniseian peoples
Original Paper | Anthropology | 2025-07-01 20:00 EDT
Tian Chen Zeng, Leonid A. Vyazov, Alexander Kim, Pavel Flegontov, Kendra Sirak, Robert Maier, Iosif Lazaridis, Ali Akbari, Michael Frachetti, Alexey A. Tishkin, Natalia E. Ryabogina, Sergey A. Agapov, Danila S. Agapov, Anatoliy N. Alekseev, Gennady G. Boeskorov, Anatoly P. Derevianko, Viktor M. Dyakonov, Dmitry N. Enshin, Alexey V. Fribus, Yaroslav V. Frolov, Sergey P. Grushin, Alexander A. Khokhlov, Kirill Yu. Kiryushin, Yurii F. Kiryushin, Egor P. Kitov, Pavel Kosintsev, Igor V. Kovtun, Nikolai P. Makarov, Viktor V. Morozov, Egor N. Nikolaev, Marina P. Rykun, Tatyana M. Savenkova, Marina V. Shchelchkova, Vladimir Shirokov, Svetlana N. Skochina, Olga S. Sherstobitova, Sergey M. Slepchenko, Konstantin N. Solodovnikov, Elena N. Solovyova, Aleksandr D. Stepanov, Aleksei A. Timoshchenko, Aleksandr S. Vdovin, Anton V. Vybornov, Elena V. Balanovska, Stanislav Dryomov, Garrett Hellenthal, Kenneth Kidd, Johannes Krause, Elena Starikovskaya, Rem Sukernik, Tatiana Tatarinova, Mark G. Thomas, Maxat Zhabagin, Kim Callan, Olivia Cheronet, Daniel Fernandes, Denise Keating, Francesca Candilio, Lora Iliev, Aisling Kearns, Kadir Toykan Özdoğan, Matthew Mah, Adam Micco, Megan Michel, Iñigo Olalde, Fatma Zalzala, Swapan Mallick, Nadin Rohland, Ron Pinhasi, Vagheesh M. Narasimhan, David Reich
The North Eurasian forest and forest-steppe zones have sustained millennia of sociocultural connections among northern peoples, but much of their history is poorly understood. In particular, the genomic formation of populations that speak Uralic and Yeniseian languages today is unknown. Here, by generating genome-wide data for 180 ancient individuals spanning this region, we show that the Early-to-Mid-Holocene hunter-gatherers harboured a continuous gradient of ancestry from fully European-related in the Baltic, to fully East Asian-related in the Transbaikal. Contemporaneous groups in Northeast Siberia were off-gradient and descended from a population that was the primary source for Native Americans, which then mixed with populations of Inland East Asia and the Amur River Basin to produce two populations whose expansion coincided with the collapse of pre-Bronze Age population structure. Ancestry from the first population, Cis-Baikal Late Neolithic-Bronze Age (Cisbaikal_LNBA), is associated with Yeniseian-speaking groups and those that admixed with them, and ancestry from the second, Yakutia Late Neolithic-Bronze Age (Yakutia_LNBA), is associated with migrations of prehistoric Uralic speakers. We show that Yakutia_LNBA first dispersed westwards from the Lena River Basin around 4,000 years ago into the Altai-Sayan region and into West Siberian communities associated with Seima-Turbino metallurgy–a suite of advanced bronze casting techniques that expanded explosively from the Altai1. The 16 Seima-Turbino period individuals were diverse in their ancestry, also harbouring DNA from Indo-Iranian-associated pastoralists and from a range of hunter-gatherer groups. Thus, both cultural transmission and migration were key to the Seima-Turbino phenomenon, which was involved in the initial spread of early Uralic-speaking communities.
Anthropology, Archaeology, Evolutionary genetics, Genetic variation
Hybrid quantum network for sensing in the acoustic frequency range
Original Paper | Atomic and molecular interactions with photons | 2025-07-01 20:00 EDT
Valeriy Novikov, Jun Jia, Túlio Brito Brasil, Andrea Grimaldi, Maïmouna Bocoum, Mikhail Balabas, Jörg Helge Müller, Emil Zeuthen, Eugene Simon Polzik
Ultimate limits for the sensing of fields and forces are set by the quantum noise of a sensor1,2,3. Entanglement allows for suppression of such noise and for achieving sensitivity beyond standard quantum limits4,5,6,7. Applicability of quantum optical sensing is often restricted by fixed wavelengths of available photonic quantum sources. Another ubiquitous limitation is associated with challenges of achieving quantum-noise-limited sensitivity in the acoustic noise frequency range relevant for several applications. Here we demonstrate a tool for broadband quantum sensing by performing quantum state processing that can be applied to a wide range of the optical spectrum and by suppressing quantum noise over an octave in the acoustic frequency range. An atomic spin ensemble is strongly coupled to one of the frequency-tunable beams of an Einstein-Podolsky-Rosen (EPR) source of light. The other EPR beam of light, entangled with the first one, is tuned to a disparate wavelength. Engineering the spin ensemble to act as a negative-mass or positive-mass oscillator, we demonstrate frequency-dependent quantum noise reduction for measurements at the disparate wavelength. The tunability of the spin ensemble enables targeting quantum noise in a variety of systems with dynamics ranging from kHz to MHz. As an example of broadband quantum noise reduction in the acoustic frequency range, we analyse the applicability of our approach to gravitational-wave detectors (GWDs). Other possible applications include continuous-variable quantum repeaters and distributed quantum sensing.
Atomic and molecular interactions with photons, Quantum mechanics, Quantum metrology, Quantum optics
Electron flow in hydrogenotrophic methanogens under nickel limitation
Original Paper | Archaeal physiology | 2025-07-01 20:00 EDT
Shunsuke Nomura, Pablo San Segundo-Acosta, Evgenii Protasov, Masanori Kaneko, Jörg Kahnt, Bonnie J. Murphy, Seigo Shima
Methanogenic archaea are the main producers of the potent greenhouse gas methane1,2. In the methanogenic pathway from CO2 and H2 studied under laboratory conditions, low-potential electrons for CO2 reduction are generated by a flavin-based electron-bifurcation reaction catalysed by heterodisulfide reductase (Hdr) complexed with the associated [NiFe]-hydrogenase (Mvh)3,4,5. F420-reducing [NiFe]-hydrogenase (Frh) provides electrons to the methanogenic pathway through the electron carrier F420 (ref. 6). Here we report that under strictly nickel-limited conditions, in which the nickel concentration is similar to those often observed in natural habitats7,8,9,10,11, the production of both [NiFe]-hydrogenases in Methanothermobacter marburgensis is strongly downregulated. The Frh reaction is substituted by a coupled reaction with [Fe]-hydrogenase (Hmd), and the role of Mvh is taken over by F420-dependent electron-donating proteins (Elp). Thus, Hmd provides all electrons for the reducing metabolism under these nickel-limited conditions. Biochemical and structural characterization of Elp-Hdr complexes confirms the electronic interaction between Elp and Hdr. The conservation of the genes encoding Elp and Hmd in CO2-reducing hydrogenotrophic methanogens suggests that the Hmd system is an alternative pathway for electron flow in CO2-reducing hydrogenotrophic methanogens under nickel-limited conditions.
Archaeal physiology, Carbon cycle, Cryoelectron microscopy, Multienzyme complexes, Proteomics
Rewiring endogenous genes in CAR T cells for tumour-restricted payload delivery
Original Paper | Immunotherapy | 2025-07-01 20:00 EDT
Amanda X. Y. Chen, Kah Min Yap, Joelle S. Kim, Kevin Sek, Yu-Kuan Huang, Phoebe A. Dunbar, Volker Wiebking, Jesse D. Armitage, Isabelle Munoz, Kirsten L. Todd, Emily B. Derrick, Dat Nguyen, Junming Tong, Cheok Weng Chan, Thang X. Hoang, Katherine M. Audsley, Marit J. van Elsas, Jim Middelburg, Joel N. Lee, Maria N. de Menezes, Thomas J. Cole, Jasmine Li, Christina Scheffler, Andrew M. Scott, Laura K. Mackay, Jason Waithman, Jane Oliaro, Simon J. Harrison, Ian A. Parish, Junyun Lai, Matthew H. Porteus, Imran G. House, Phillip K. Darcy, Paul A. Beavis
The efficacy of chimeric antigen receptor (CAR) T cell therapy in solid tumours is limited by immunosuppression and antigen heterogeneity1,2,3. To overcome these barriers, ‘armoured’ CAR T cells, which secrete proinflammatory cytokines, have been developed4. However, their clinical application has been limited because of toxicity related to peripheral expression of the armouring transgene5. Here, we have developed a CRISPR knock-in strategy that leverages the regulatory mechanisms of endogenous genes to drive transgene expression in a tumour-localized manner. By screening endogenous genes with tumour-restricted expression, we have identified the NR4A2 and RGS16 promoters as promising candidates to support the delivery of cytokines such as IL-12 and IL-2 directly to the tumour site, leading to enhanced antitumour efficacy and long-term survival of mice in both syngeneic and xenogeneic models. This effect was concomitant with improved CAR T cell polyfunctionality, activation of endogenous antitumour immunity and a favourable safety profile, and was applicable in CAR T cells from patients.
Immunotherapy, Tumour immunology
Inter-brain neural dynamics in biological and artificial intelligence systems
Original Paper | Computational neuroscience | 2025-07-01 20:00 EDT
Xingjian Zhang, Nguyen Phi, Qin Li, Ryan Gorzek, Niklas Zwingenberger, Shan Huang, John L. Zhou, Lyle Kingsbury, Tara Raam, Ye Emily Wu, Don Wei, Jonathan C. Kao, Weizhe Hong
Social interaction can be regarded as a dynamic feedback loop between interacting individuals as they act and react to each other1,2. Here, to understand the neural basis of these interactions, we investigated inter-brain neural dynamics across individuals in both mice and artificial intelligence systems. By measuring activities of molecularly defined neurons in the dorsomedial prefrontal cortex of socially interacting mice, we find that the multi-dimensional neural space within each individual can be partitioned into two distinct subspaces–a shared neural subspace that represents shared neural dynamics across animals and a unique neural subspace that represents activity unique to each animal. Notably, compared with glutamatergic neurons, GABAergic (γ-aminobutyric acid-producing) neurons in the dorsomedial prefrontal cortex contain a considerably larger shared neural subspace, which arises from behaviours of both self and others. We extended this framework to artificial intelligence agents and observed that, as social interactions emerged, so too did shared neural dynamics between interacting agents. Importantly, selectively disrupting the neural components that contribute to shared neural dynamics substantially reduces the agents’ social actions. Our findings suggest that shared neural dynamics represent a fundamental and generalizable feature of interacting neural systems present in both biological and artificial agents and highlight the functional significance of shared neural dynamics in driving social interactions.
Computational neuroscience, Social behaviour
Close-in planet induces flares on its host star
Original Paper | Core processes | 2025-07-01 20:00 EDT
Ekaterina Ilin, Harish K. Vedantham, Katja Poppenhäger, Sanne Bloot, Joseph R. Callingham, Alexis Brandeker, Hritam Chakraborty
In the past decade, hundreds of exoplanets have been discovered in extremely short orbits below 10 days. Unlike in the Solar System, planets in these systems orbit their host stars close enough to disturb the stellar magnetic field lines1. The interaction can enhance the magnetic activity of the star, such as its chromospheric2 and radio3 emission or flaring4. So far, the search for magnetic star-planet interactions has remained inconclusive. Here we report the detection of planet-induced flares on HIP 67522, a 17 million-year-old G dwarf star with two known close-in planets5,6. Combining space-borne photometry from the Transiting Exoplanet Survey Satellite and dedicated Characterising Exoplanets Telescope observations over 5 years, we find that the 15 flares in HIP 67522 cluster near the transit phase of the innermost planet, indicating persistent magnetic star-planet interaction in the system. The stability of interaction implies that the innermost planet is continuously self-inflicting a six times higher flare rate than it would experience without interaction. The subsequent flux of energetic radiation and particles bombarding HIP 67522 b may explain the remarkably extended atmosphere of the planet, recently detected with the James Webb Space Telescope7. HIP 67522 is, therefore, an archetype to understand the impact of magnetic star-planet interaction on the atmospheres of nascent exoplanets.
Core processes, Exoplanets, Stars, Time-domain astronomy
A foundation model to predict and capture human cognition
Original Paper | Computational science | 2025-07-01 20:00 EDT
Marcel Binz, Elif Akata, Matthias Bethge, Franziska Brändle, Fred Callaway, Julian Coda-Forno, Peter Dayan, Can Demircan, Maria K. Eckstein, Noémi Éltető, Thomas L. Griffiths, Susanne Haridi, Akshay K. Jagadish, Li Ji-An, Alexander Kipnis, Sreejan Kumar, Tobias Ludwig, Marvin Mathony, Marcelo Mattar, Alireza Modirshanechi, Surabhi S. Nath, Joshua C. Peterson, Milena Rmus, Evan M. Russek, Tankred Saanum, Johannes A. Schubert, Luca M. Schulze Buschoff, Nishad Singhi, Xin Sui, Mirko Thalmann, Fabian J. Theis, Vuong Truong, Vishaal Udandarao, Konstantinos Voudouris, Robert Wilson, Kristin Witte, Shuchen Wu, Dirk U. Wulff, Huadong Xiong, Eric Schulz
Establishing a unified theory of cognition has been an important goal in psychology1,2. A first step towards such a theory is to create a computational model that can predict human behaviour in a wide range of settings. Here we introduce Centaur, a computational model that can predict and simulate human behaviour in any experiment expressible in natural language. We derived Centaur by fine-tuning a state-of-the-art language model on a large-scale dataset called Psych-101. Psych-101 has an unprecedented scale, covering trial-by-trial data from more than 60,000 participants performing in excess of 10,000,000 choices in 160 experiments. Centaur not only captures the behaviour of held-out participants better than existing cognitive models, but it also generalizes to previously unseen cover stories, structural task modifications and entirely new domains. Furthermore, the model’s internal representations become more aligned with human neural activity after fine-tuning. Taken together, our results demonstrate that it is possible to discover computational models that capture human behaviour across a wide range of domains. We believe that such models provide tremendous potential for guiding the development of cognitive theories, and we present a case study to demonstrate this.
Computational science, Human behaviour, Neuroscience
WSTF nuclear autophagy regulates chronic but not acute inflammation
Original Paper | Inflammation | 2025-07-01 20:00 EDT
Yu Wang, Vinay V. Eapen, Yaosi Liang, Athanasios Kournoutis, Marc Samuel Sherman, Yanxin Xu, Angelique Onorati, Xianting Li, Xiaoting Zhou, Kathleen E. Corey, Kuo Du, Ana Maria Cabral Burkard, Chia-Kang Ho, Jing Xie, Hui Zhang, Raquel Maeso-Díaz, Xinyi Ma, Ulrike Rieprecht, Tara O’Brien, Murat Cetinbas, Lu Wang, Jihe Liu, Corey Bretz, Aaron P. Havas, Zhuo Zhou, Shannan J. Ho Sui, Srinivas Vinod Saladi, Ruslan I. Sadreyev, Peter D. Adams, Robert E. Kingston, Anna Mae Diehl, Benjamin Alman, Wolfram Goessling, Zhenyu Yue, Xiao-Fan Wang, Terje Johansen, Zhixun Dou
Acute inflammation is an essential response that our bodies use to combat infections1. However, in the absence of infections, chronic inflammation can have a pivotal role in the onset and progression of chronic diseases, such as arthritis, cancer, autoimmune disorders, metabolic-dysfunction-associated steatohepatitis (MASH), and most ageing-associated pathologies2,3. The underlying mechanisms that distinguish chronic inflammation from its acute counterpart remain unclear, posing challenges to the development of targeted therapies for these major diseases. Here we identify a mechanism that separates the two responses: during chronic but not acute inflammation, chromatin remodelling is influenced by nuclear autophagy, in which the WSTF protein of the ISWI chromatin-remodelling complex interacts with the ATG8 autophagy protein family in the nucleus. This interaction leads to WSTF nuclear export and subsequent degradation by autophagosomes and lysosomes in the cytoplasm. Loss of WSTF leads to chromatin opening over inflammatory genes, amplifying inflammation. Cell-penetrating peptides that block the WSTF-ATG8 interaction do not affect acute inflammation but suppress chronic inflammation in senescence as well as in MASH and osteoarthritis in mouse models and patient samples. The ability to specifically target chronic inflammation without blunting acute inflammation offers an approach for treating common chronic inflammatory diseases.
Inflammation, Senescence
PPP2R1A mutations portend improved survival after cancer immunotherapy
Original Paper | Cancer immunotherapy | 2025-07-01 20:00 EDT
Yibo Dai, Anne Knisely, Mitsutake Yano, Minghao Dang, Emily M. Hinchcliff, Sanghoon Lee, Annalyn Welp, Manoj Chelvanambi, Matthew Lastrapes, Heng Liu, Zhe Yuan, Chen Wang, Hao Nie, Stephanie Jean, Luis J. Montaner, Jiakai Hou, Ami Patel, Shrina Patel, Bryan Fellman, Ying Yuan, Baohua Sun, Renganayaki Krishna Pandurengan, Edwin Roger Parra Cuentas, Joseph Celestino, Yan Liu, Jinsong Liu, R. Tyler Hillman, Shannon N. Westin, Anil K. Sood, Pamela T. Soliman, Aaron Shafer, Larissa A. Meyer, David M. Gershenson, David Vining, Dhakshinamoorthy Ganeshan, Karen Lu, Jennifer A. Wargo, Weiyi Peng, Rugang Zhang, Linghua Wang, Amir A. Jazaeri
Immune checkpoint blockade (ICB) therapy is effective against many cancers, although resistance remains a major issue and new strategies are needed to improve clinical outcomes1,2,3,4,5. Here we studied ICB response in a cohort of patients with ovarian clear cell carcinoma–a cancer type that poses considerable clinical challenges and lacks effective therapies6,7,8. We observed significantly prolonged overall survival and progression-free survival in patients with tumours with PPP2R1A mutations. Importantly, our findings were validated in additional ICB-treated patient cohorts across multiple cancer types. Translational analyses from tumour biopsies demonstrated enhanced IFNγ signalling, and the presence of tertiary lymphoid structures at the baseline, as well as enhanced immune infiltration and expansion of CD45RO+CD8+ T cells in the tumour neighbourhood after ICB treatment in PPP2R1A-mutated tumours. Parallel preclinical investigations showed that targeting PPP2R1A (by pharmacological inhibition or genetic modifications) in in vitro and in vivo models was associated with improved survival in the setting of treatment with several forms of immunotherapy, including chimeric antigen receptor (CAR)-T cell therapy and ICB. The results from these studies suggest that therapeutic targeting of PPP2R1A may represent an effective strategy to improve patient outcomes after ICB or other forms of immunotherapy, although additional mechanistic and therapeutic insights are needed.
Cancer immunotherapy, Ovarian cancer, Tumour biomarkers
Discovering cognitive strategies with tiny recurrent neural networks
Original Paper | Computational models | 2025-07-01 20:00 EDT
Li Ji-An, Marcus K. Benna, Marcelo G. Mattar
Understanding how animals and humans learn from experience to make adaptive decisions is a fundamental goal of neuroscience and psychology. Normative modelling frameworks such as Bayesian inference1 and reinforcement learning2 provide valuable insights into the principles governing adaptive behaviour. However, the simplicity of these frameworks often limits their ability to capture realistic biological behaviour, leading to cycles of handcrafted adjustments that are prone to researcher subjectivity. Here we present a novel modelling approach that leverages recurrent neural networks to discover the cognitive algorithms governing biological decision-making. We show that neural networks with just one to four units often outperform classical cognitive models and match larger neural networks in predicting the choices of individual animals and humans, across six well-studied reward-learning tasks. Critically, we can interpret the trained networks using dynamical systems concepts, enabling a unified comparison of cognitive models and revealing detailed mechanisms underlying choice behaviour. Our approach also estimates the dimensionality of behaviour3 and offers insights into algorithms learned by meta-reinforcement learning artificial intelligence agents. Overall, we present a systematic approach for discovering interpretable cognitive strategies in decision-making, offering insights into neural mechanisms and a foundation for studying healthy and dysfunctional cognition.
Computational models, Human behaviour, Learning algorithms
Carbonate formation and fluctuating habitability on Mars
Original Paper | Planetary science | 2025-07-01 20:00 EDT
Edwin S. Kite, Benjamin M. Tutolo, Madison L. Turner, Heather B. Franz, David G. Burtt, Thomas F. Bristow, Woodward W. Fischer, Ralph E. Milliken, Abigail A. Fraeman, Daniel Y. Zhou
The cause of Mars’s loss of surface habitability is unclear, with isotopic data suggesting a ‘missing sink’ of carbonate1. Past climates with surface and shallow-subsurface liquid water are recorded by Mars’s sedimentary rocks, including strata in the approximately 4-km-thick record at Gale Crater2. Those waters were intermittent, spatially patchy and discontinuous, and continued remarkably late in Mars’s history3–attributes that can be understood if, as on Earth, sedimentary-rock formation sequestered carbon dioxide as abundant carbonate (recently confirmed in situ at Gale4). Here we show that a negative feedback among solar luminosity, liquid water and carbonate formation can explain the existence of intermittent Martian oases. In our model, increasing solar luminosity promoted the stability of liquid water, which in turn formed carbonate, reduced the partial pressure of atmospheric carbon dioxide and limited liquid water5. Chaotic orbital forcing modulated wet-dry cycles. The negative feedback restricted liquid water to oases and Mars self-regulated as a desert planet. We model snowmelt as the water source, but the feedback can also work with groundwater as the water source. Model output suggests that Gale faithfully records the expected primary episodes of liquid water stability in the surface and near-surface environment. Eventually, atmospheric thickness approaches water’s triple point, curtailing the sustained stability of liquid water and thus habitability in the surface environment. We assume that the carbonate content found at Gale is representative, and as a result we present a testable idea rather than definitive evidence.
Planetary science
Ultrabroadband and band-selective thermal meta-emitters by machine learning
Original Paper | Green photonics | 2025-07-01 20:00 EDT
Chengyu Xiao, Mengqi Liu, Kan Yao, Yifan Zhang, Mengqi Zhang, Max Yan, Ya Sun, Xianghui Liu, Xuanyu Cui, Tongxiang Fan, Changying Zhao, Wansu Hua, Yinqiao Ying, Yuebing Zheng, Di Zhang, Cheng-Wei Qiu, Han Zhou
Thermal nanophotonics enables fundamental breakthroughs across technological applications from energy technology to information processing1,2,3,4,5,6,7,8,9,10,11. From thermal emitters to thermophotovoltaics and thermal camouflage, precise spectral engineering has been bottlenecked by trial-and-error approaches. Concurrently, machine learning has demonstrated its powerful capabilities in the design of nanophotonic and meta-materials12,13,14,15,16,17,18. However, it remains a considerable challenge to develop a general design methodology for tailoring high-performance nanophotonic emitters with ultrabroadband control and precise band selectivity, as they are constrained by predefined geometries and materials, local optimization traps and traditional algorithms. Here we propose an unconventional machine learning-based paradigm that can design a multitude of ultrabroadband and band-selective thermal meta-emitters by realizing multiparameter optimization with sparse data that encompasses three-dimensional structural complexity and material diversity. Our framework enables dual design capabilities: (1) it automates the inverse design of a vast number of possible metastructure and material combinations for spectral tailoring; (2) it has an unprecedented ability to design various three-dimensional meta-emitters by applying a three-plane modelling method that transcends the limitations of traditional, flat, two-dimensional structures. We present seven proof-of-concept meta-emitters that exhibit superior optical and radiative cooling performance surpassing current state-of-the-art designs. We provide a generalizable framework for fabricating three-dimensional nanophotonic materials, which facilitates global optimization through expanded geometric freedom and dimensionality and a comprehensive materials database.
Green photonics, Metamaterials
Nature Materials
A carbon-nanotube-based electron source with a 0.3-eV energy spread and an unconventional time delay
Original Paper | Carbon nanotubes and fullerenes | 2025-07-01 20:00 EDT
Ke Chen, Chao Yu, Xiaowei Wang, Shenghan Zhou, Li Wang, Yusong Qu, Aiwei Wang, Fan Xiao, Zhenjun Li, Chi Li, Jiayu Dai, Xiangang Wan, Ruifeng Lu, Qing Dai
Conventional metal-tip-based laser-driven electron sources are normally constrained by a trade-off between energy spread and pulse width due to optical-field-induced free electron acceleration. This makes it challenging to surpass the current state-of-the-art, which exhibits energy spreads exceeding 1 eV and pulse durations of hundreds of femtoseconds. Here we report an unconventional delayed emission from a one-dimensional carbon-nanotube-based electron source. By utilizing a special pump-probe approach, we apply 7-fs laser pulses to the carbon-nanotube emitters and observe free electron emission tens of femtoseconds after the pulse. This delayed emission results in a substantially reduced energy spread of approximately 0.3 eV and an electron pulse width of about 13 fs. Through time-dependent density functional theory calculations, we find that the delayed emission is driven by the interplay of collective oscillations and electron-electron interactions. Our results may provide a promising technology for developing cutting-edge ultrafast electron sources.
Carbon nanotubes and fullerenes
Nature Physics
Anyonic braiding in a chiral Mach-Zehnder interferometer
Original Paper | Quantum Hall | 2025-07-01 20:00 EDT
Bikash Ghosh, Maria Labendik, Liliia Musina, Vladimir Umansky, Moty Heiblum, David F. Mross
Fractional quantum statistics are the defining characteristic of anyons. Measuring the phase generated by an exchange of anyons is challenging, as standard interferometry set-ups–such as the Fabry-Pérot interferometer–suffer from charging effects that obscure the interference signal. Here we present the observation of anyonic interference and exchange phases in an optical-like Mach-Zehnder interferometer based on co-propagating interface modes. By avoiding backscattering and deleterious charging effects, this set-up enables pristine and robust Aharonov-Bohm interference without any phase slips. At various fractional filling factors, the observed flux periodicities agree with the fundamental fractionally charged excitations that correspond to Jain states and depend only on the bulk topological order. To probe the anyonic statistics, we used a small, charged top gate in the interferometer bulk to induce localized quasiparticles without modifying the Aharonov-Bohm phase. The added quasiparticles introduce periodic phase slips. The sign and magnitude of the observed phase slips align with the expected value at filling 1/3, but their direction shows systematic deviations at fillings 2/5 and 3/7. Control over added individual quasiparticles in this design is essential for measuring the coveted non-abelian statistics in the future.
Quantum Hall, Quantum mechanics
Physical Review Letters
Classical Simulation of Circuits with Realistic Odd-Dimensional Gottesman-Kitaev-Preskill States
Research article | Quantum circuits | 2025-07-01 06:00 EDT
Cameron Calcluth, Oliver Hahn, Juani Bermejo-Vega, Alessandro Ferraro, and Giulia Ferrini
Classically simulating circuits with bosonic codes is challenging due to the prohibitive cost of simulating quantum systems with many, possibly infinite, energy levels. We propose an algorithm to simulate circuits with encoded Gottesman-Kitaev-Preskill (GKP) states, specifically for odd-dimensional encoded qudits. Our approach is tailored to be especially effective in the most challenging but practically relevant regime, where the codeword states exhibit high (but finite) squeezing. Our algorithm leverages the Zak-Gross Wigner function introduced by Davis, Fabre, and Chabaud, which represents infinitely squeezed encoded stabilizer states positively. The run-time of the algorithm scales with the negativity of the Wigner function, allowing for efficient simulation of certain large-scale circuits—namely, input stabilizer GKP states undergoing generalized GKP-encoded Clifford operations followed by modular measurement—with a high degree of squeezing. For stabilizer GKP states exhibiting 12 dB of squeezing, our algorithm can simulate circuits with up to 1000 modes with less than double the number of samples required for a single input mode, which is in stark contrast to existing simulators. Therefore, this approach holds significant potential for benchmarking early implementations of quantum computing architectures utilizing bosonic codes.
Phys. Rev. Lett. 135, 010601 (2025)
Quantum circuits, Quantum computation, Quantum information processing, Quantum information processing with continuous variables, Quantum information theory, Qudits
Experimental Quantum Fingerprinting without the Shared Randomness Loophole
Research article | Quantum communication | 2025-07-01 06:00 EDT
Ao Shen, Yu-Shuo Lu, Xiping Wu, Jinping Lin, Xiao-Yu Cao, Chengfang Ge, Shan-Feng Shao, Hua-Lei Yin, Lai Zhou, and Zhiliang Yuan
Quantum fingerprinting (QF) promises exponential reduction of information transmission in executing communication complexity tasks. Practicality and quantum advantage of this novel protocol has been recently demonstrated using weak coherent pulses to carry the fingerprinting information. However, all coherent QF implementations rely upon a direct optical link to maintain coherence between the users, which does not comply with the protocol’s rule that the users must not have any access to a shared randomness. To close this loophole, we propose, and experimentally demonstrate, a novel protocol based on asynchronous coincidence pairing from the interference result between coherent optical fields that are remotely and independently prepared. Over a length of 20 km telecom fiber, our QF setup has outperformed the best-known classical algorithm, for the first time without being susceptible to shared randomness. Our result paves the way toward practical applications of QF in communication complexity.
Phys. Rev. Lett. 135, 010801 (2025)
Quantum communication, Quantum networks, Quantum protocols
Practical Framework for Analyzing High-Dimensional Quantum Key Distribution Setups
Research article | Quantum communication | 2025-07-01 06:00 EDT
Florian Kanitschar and Marcus Huber
High-dimensional (HD) entanglement promises both enhanced key rates and overcoming obstacles faced by modern-day quantum communication. However, modern convex optimization-based security arguments are limited by computational constraints; thus, accessible dimensions are far exceeded by progress in HD photonics, bringing forth a need for efficient methods to compute key rates for large encoding dimensions. In response to this problem, we present a flexible analytic framework facilitated by the dual of a semidefinite program and diagonalizing operators inspired by entanglement-witness theory, enabling the efficient computation of key rates in high-dimensional systems. To facilitate the latter, we show how matrix completion techniques can be incorporated to effectively yield improved, computable bounds on the key rate in paradigmatic high-dimensional systems of time- or frequency-bin entangled photons and beyond, revealing the potential for very high-dimensions to surpass low dimensional protocols already with existing technology. In our accompanying work, (F. Kanitschar and M. Huber, Composable finite-size security of high-dimensional quantum key distribution protocols), available on arXiv, we show how our findings can be used to establish finite-size security against coherent attacks for general HD-QKD protocols both in the fixed- and variable-length scenario.
Phys. Rev. Lett. 135, 010802 (2025)
Quantum communication, Quantum communication, protocols & technology, Quantum protocols
Absorption of Fermionic Dark Matter in the PICO-60 ${\mathrm{C}}{3}{\mathrm{F}}{8}$ Bubble Chamber
Research article | Dark matter direct detection | 2025-07-01 06:00 EDT
E. Adams et al. (PICO Collaboration)
*et al.*Using a bubble chamber, world-leading constraints are placed on the absorption of hypothetical fermionic dark matter, including the first limits on spin-dependent absorptive interactions.
Phys. Rev. Lett. 135, 011001 (2025)
Dark matter direct detection, Particle dark matter, Dark matter detectors
Preponderant Orbital Polarization in Relativistic Magnetovortical Matter
Research article | Gauge theories | 2025-07-01 06:00 EDT
Kenji Fukushima, Koichi Hattori, and Kazuya Mameda
We establish thermodynamic stability and gauge invariance in the magnetovortical matter of Dirac fermions under the coexistent rotation and strong magnetic field. The corresponding partition function reveals that the orbital contribution to bulk thermodynamics preponderates over the conventional contribution from anomaly-related spin effects. This orbital preponderance macroscopically manifests itself in the sign inversion of the induced charge and current in the magnetovortical matter, and can be tested experimentally as the flip of the angular momentum polarization of magnetovortical matter when the magnetic field strength is increased.
Phys. Rev. Lett. 135, 011601 (2025)
Gauge theories, Landau levels, Quantum field theory, Spin polarization, Thermodynamics, Angular momentum
Novel Approach to Investigate ATOMKI Anomaly Using Coherent CAPTAIN-Mills Detectors
Research article | Electroweak interactions in nuclear physics | 2025-07-01 06:00 EDT
Bhaskar Dutta, Bai-Shan Hu, Wei-Chih Huang, and Richard G. Van de Water
ATOMKI nuclear anomaly has suggested a new BSM (beyond the standard model) boson with mass $\sim 17\text{ }\text{ }\mathrm{MeV}$ emitted from excited nuclei and quickly decays into a pair of ${e}^{+}{e}^{- }$. In order to search for the new particle, we propose a new approach that utilizes the ongoing coherent CAPTAIN-Mills (CCM) ten-ton LAr (liquid argon) detectors. The neutrons from the Lujan target can scatter inelastically, but the PMT glass in the CCM detector can produce the new boson which solves the ATOMKI anomaly. The new boson can be detected from its decay to a ${e}^{+}{e}^{- }$ pair. We find that CCM probes a large area of the anomaly-allowable parameter space. We also show the prediction for a 100-ton LAr detector and five-ton EOS water detector.
Phys. Rev. Lett. 135, 011801 (2025)
Electroweak interactions in nuclear physics, Hypothetical particle physics models, Nuclear decay, Nucleon induced nuclear reactions, Phenomenology, Hypothetical gauge bosons, Ab initio calculations, Dark matter detectors, Nuclear many-body theory
Dark Matter Search Results from $4.2\text{ }\text{ }\text{Tonne}\text{- }\text{Years}$ of Exposure of the LUX-ZEPLIN (LZ) Experiment
Research article | Dark matter direct detection | 2025-07-01 06:00 EDT
J. Aalbers et al. (LZ Collaboration)
*et al.*Seven metric tons of liquid xenon get closer than ever to revealing WIMPs.
Phys. Rev. Lett. 135, 011802 (2025)
Dark matter direct detection, Particle dark matter, Weakly interacting massive particles, Dark matter detectors, Time-projection chambers
Hadronic Vacuum Polarization for the Muon $g- 2$ from Lattice QCD: Long-Distance and Full Light-Quark Connected Contribution
Research article | Magnetic moment | 2025-07-01 06:00 EDT
Alexei Bazavov, Claude W. Bernard, David A. Clarke, Christine Davies, Carleton DeTar, Aida X. El-Khadra, Elvira Gámiz, Steven Gottlieb, Anthony V. Grebe, Leon Hostetler, William I. Jay, Hwancheol Jeong, Andreas S. Kronfeld, Shaun Lahert, Jack Laiho, G. Peter Lepage, Michael Lynch, Andrew T. Lytle, Craig McNeile, Ethan T. Neil, Curtis T. Peterson, James N. Simone, Jacob W. Sitison, Ruth S. Van de Water, and Alejandro Vaquero (Fermilab Lattice, HPQCD, and MILC Collaborations)
We present results for the dominant light-quark connected contribution to the long-distance window of the hadronic vacuum polarization (HVP) contribution to the muon $g- 2$ from lattice quantum chromodynamics. Specifically, with a new determination of the lattice scale on MILC’s physical-mass HISQ ensembles, using the ${\mathrm{\Omega }}^{- }$ baryon mass, we obtain a result of ${a}{\mu }^{ll,\mathrm{LD}}(\mathrm{conn})=400.2(2.3{)}{\mathrm{stat}}(3.7{)}{\mathrm{syst}}[4.3{]}{\text{total}}\times{}\phantom{\rule{0ex}{0ex}}{10}^{- 10}$. Summing this result with our recent determinations of the light-quark connected contributions to the short- and intermediate-distance windows, we obtain a subpercent precision determination of the light-quark-connected contribution to HVP of ${a}{\mu }^{ll}(\mathrm{conn})=655.2(2.3{)}{\mathrm{stat}}(3.9{)}{\mathrm{syst}}[4.5{]}{\text{total}}\times{}{10}^{- 10}$. Finally, as a consistency check, we verify that an independent analysis of the full contribution is in agreement with the sum of individual windows. We discuss our future plans for improvements of our HVP calculations to meet the target precision of the Fermilab $g- 2$ experiment.
Phys. Rev. Lett. 135, 011901 (2025)
Magnetic moment, Muons, Lattice QCD
Wave-Kinetic Dynamics of Forced-Dissipated Turbulent Internal Gravity Waves
Research article | Stratified geophysical flows | 2025-07-01 06:00 EDT
Vincent Labarre, Giorgio Krstulovic, and Sergey Nazarenko
An investigation of internal gravity waves provides valuable insights into the dynamics of stratified media such as ocean and atmospheric systems.
Phys. Rev. Lett. 135, 014101 (2025)
Stratified geophysical flows, Stratified turbulence, Wave-turbulence interactions, Weak turbulence
Photonic Rabi Oscillations in Defective Plasma Photonic Crystals
Research article | Laser-plasma interactions | 2025-07-01 06:00 EDT
Xiao-Bo Zhang, Su-Ming Weng, Hong Ai, Xin Qiao, Ju-Kui Xue, and Zheng-Ming Sheng
By interacting a femtosecond probe laser pulse with a defective plasma photonic crystal, the Rabi oscillation frequency can be flexibly tuned, providing a novel way to manipulate laser pulse propagation for various high-intensity applications.
Phys. Rev. Lett. 135, 015101 (2025)
Laser-plasma interactions, Plasma optics, Plasma crystals, Rabi model
Symmetry-Based Classification of Exact Flat Bands in Single and Bilayer Moir'e Systems
Research article | Flat bands | 2025-07-01 06:00 EDT
Siddhartha Sarkar, Xiaohan Wan, Shi-Zeng Lin, and Kai Sun
Landau levels have been central to the discovery of exotic quantum phases and their unprecedentedly deep roots in geometry and topology. A powerful concept called ‘’vortexability’’ extends this framework to moir'e systems. In this Letter, we show that vortexable systems support not only Landau-level-like flat bands but also entirely new types with distinct topological properties. Notably, while ${n}{b}$ Landau levels have total Chern number $C={n}{b}$, vortexable moir'e systems can host ${n}{b}$ flat bands with $C=1\ne {n}{b}$. We provide a complete classification of such exact flat bands in single and bilayer systems with Dirac or quadratic band crossings, identifying the symmetry conditions that govern their number and topology. Up to six flat bands can be symmetry protected. We construct explicit wave functions, showing that sublattice-polarized states always sum to Chern number $\pm{}1$ and satisfy ideal non-Abelian quantum geometry. When the Berry curvature is sharply peaked, we show that a topological heavy-fermion description remains valid—even for bands with high degeneracy.
Phys. Rev. Lett. 135, 016501 (2025)
Flat bands, Strongly correlated systems, Topological materials, Twisted bilayer graphene
Quasisymmetry-Constrained Spin Ferromagnetism in Altermagnets
Research article | Magnetic order | 2025-07-01 06:00 EDT
Mercè Roig, Yue Yu, Rune C. Ekman, Andreas Kreisel, Brian M. Andersen, and Daniel F. Agterberg
Altermagnets break time-reversal symmetry, and their spin-orbit coupling (SOC) allows for an anomalous Hall effect (AHE) that depends on the direction of the N'eel ordering vector. The AHE and the ferromagnetic spin moment share the same symmetry and hence are usually proportional. However, density functional theory (DFT) calculations find that the AHE exists with negligible ferromagnetic spin moment for some compounds, whereas it reaches sizable values for other altermagnets. By examining realistic minimal models for altermagnetism in which the DFT phenomenology is captured, we uncover a general SOC-enabled quasisymmetry, the uniaxial spin space group, that provides a natural explanation for the amplitude of the ferromagnetic spin moment across the vast range of different altermagnetic materials. Additionally, we derive analytic expressions for the magnetic anisotropy energy, providing a simple means of identifying the preferred N'eel vector orientation for altermagnets.
Phys. Rev. Lett. 135, 016703 (2025)
Magnetic order, Spin-orbit coupling, Altermagnets, Symmetries in condensed matter, Tight-binding model
Phyllotactic Structures in Radially Growing Spatial Symmetry Breaking Systems
Research article | Diffusion | 2025-07-01 06:00 EDT
G. Facchini, M. A. Budroni, G. Schuszter, Fabian Brau, and A. De Wit
Phyllotactic patterns, where elements such as leaves, seeds, or droplets arrange along alternate spirals, are fascinating examples of complex structures encountered in nature. In botany, their symmetries develop when a new primordium periodically grows in the largest gap left between the previous one and the apex. Experiments using ferrofluid droplets have shown that phyllotactic patterns can also spontaneously form when identical elements repulsing each other are periodically released at a given distance from an injection center and are advected radially at a constant speed. Here, we show that phyllotactic structures can also genuinely develop in the large class of spatial symmetry breaking systems with an intrinsic wavelength in the case of radial growth. The constraint of maintaining a fixed wavelength between spots while expanding radially either diffusively or advectively generalizes the concept of temporal release of repulsing agents in botany to new classes of systems. We explore this on three different systems: numerically on two models describing reaction-driven phase transitions and spatial Turing patterns, respectively, and experimentally on chemical precipitation patterns. This paves the way to engineer new complex self-organized structures in a panoply of different systems, ranging from spinodal decomposition, chemical, biological or optical Turing structures, and Liesegang patterns, to name a few.
Phys. Rev. Lett. 135, 018001 (2025)
Diffusion, Growth, Pattern formation, Patterning, Self-assembly
Comment on ‘’Accurate Correlation Potentials from the Self-Consistent Random Phase Approximation’’
Article commentary | | 2025-07-01 06:00 EDT
Chandra Shahi and John P. Perdew
Phys. Rev. Lett. 135, 019601 (2025)
Trushin et al. Reply:
Reply | | 2025-07-01 06:00 EDT
Egor Trushin, Steffen Fauser, Andreas Mölkner, Jannis Erhard, and Andreas Görling
Phys. Rev. Lett. 135, 019602 (2025)
Physical Review X
Experimental Signatures of Hilbert-Space Ergodicity: Universal Bitstring Distributions and Applications in Noise Learning
Research article | Nonequilibrium statistical mechanics | 2025-07-01 06:00 EDT
Adam L. Shaw, Daniel K. Mark, Joonhee Choi, Ran Finkelstein, Pascal Scholl, Soonwon Choi, and Manuel Endres
An analog quantum simulator shows that while local parts of a quantum system appear thermalized, global properties exhibit persistent, universal fluctuations–offering new insight into quantum thermalization.
Phys. Rev. X 15, 031001 (2025)
Nonequilibrium statistical mechanics, Quantum fluctuations & noise, Quantum information processing, Quantum simulation
Decoherence and Wave-Function Deformation of ${D}_{4}$ Non-Abelian Topological Order
Research article | Open quantum systems & decoherence | 2025-07-01 06:00 EDT
Pablo Sala, Jason Alicea, and Ruben Verresen
Non-Abelian topological systems show greater resistance to a certain type of noise than simpler Abelian ones, revealing new potential for building more robust quantum memories.
Phys. Rev. X 15, 031002 (2025)
Open quantum systems & decoherence, Quantum information theory, Topological order
arXiv
The Ising model and random fields of scales
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-02 20:00 EDT
Random fields of scales result when the class of musical scales is thought as a set of sites, and a site can be in one of two possible states (or spins): On or Off. We present a flexible simulated annealing model that produces generic configurations arising from equilibrium states (or Gibbs measures) associated to hamiltonian energy functions defined in terms of musical interactions with parameters that can be manipulated to customize properties of the scales. The starting point is to think of the set of scales as the combinatorial class of integer compositions and the final result is an effective thermodynamic search engine implemented in an open access application for the 12-TET tuning system: Scaletor.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph), Probability (math.PR)
41 pages, 23 figures, additional material at this https URL
Electrostatic Charge Fractionalization and Unconventional Superconductivity in Strained Monolayer Graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Elias Andrade, Alejandro Jimeno-Pozo, Pierre A. Pantaleon, Francisco Guinea, Gerardo G. Naumis
Two-dimensional systems with flat bands support correlated phases such as superconductivity and charge fractionalization. While twisted moire systems like twisted bilayer graphene have revealed such states, they remain complex to control. Here, we study monolayer graphene under uniaxial periodic strain, which forms a 1D moire and hosts two flat, sublattice-polarized bands. It is shown that this system exhibits features akin to its twisted counterparts, such as a pinning of the Fermi level to the van Hove singularity and unconventional superconductivity. We also found inhomogeneous charge density waves for rational fractional fillings of the unit cell
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 4 figures and supplementary material. Comments are very welcome
Majoranas with a twist: Tunable Majorana zero modes in altermagnetic heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Andreas Hadjipaschalis, Sayed Ali Akbar Ghorashi, Jennifer Cano
Altermagnetism provides new routes to realize Majorana zero modes with vanishing net magnetization. We consider a recently proposed heterostructure consisting of a semiconducting wire on top of an altermagnet and with proximity-induced superconductivity. We demonstrate that rotating the wire serves as a tuning knob to induce the topological phase. For $ d$ -, $ g$ - and $ i$ -wave altermagnetic pairing, we derive angle-dependent topological gap-closing conditions. We derive symmetry constraints on angles where the induced altermagnetism must vanish, which we verify by explicit models. Our results imply that a bent or curved wire realizes a spatially-dependent topological invariant with Majorana zero modes pinned to positions where the topological invariant changes. This provides a new experimental set-up whereby a single wire can host both topologically trivial and nontrivial regimes without $ in$ $ situ$ tuning.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages
Detection of 2D SPT phases under decoherence
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Naren Manjunath, Alex Turzillo, Chong Wang
We propose a bulk order parameter for extracting symmetry-protected topological (SPT) invariants of quantum many-body mixed states on a two dimensional lattice using partial symmetries. The procedure builds on the partial symmetry order parameter recently developed by some of the authors to study SPT phases of pure states and adapts them to the decohered setting. For a symmetry $ G = E \times A$ where $ E$ is a strong symmetry and $ A$ is a weak symmetry, we show that the partial symmetry order parameter detects SPT invariants jointly protected by $ E$ and $ A$ . We demonstrate this explicitly using a class of mixed states obtained from CZX-type models with $ \mathbb{Z}_2\times\mathbb{Z}_2$ symmetry and subjecting them to noise that weakens one of the $ \mathbb{Z}_2$ symmetries. We also comment on the practical detection of SPT invariants in quantum simulators through randomized measurements.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
6+4 pages
Majorana zero modes in semiconductor-superconductor hybrid structures: Defining topology in short and disordered nanowires through Majorana splitting
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Majorana zero modes (MZMs) are bound midgap excitations at the ends of a 1D topological superconductor, which must come in pairs. If the two MZMs in the pair are sufficiently well-separated by a distance much larger than their individual localization length, then the MZMs behave as non-Abelian anyons which can be braided to carry out fault-tolerant topological quantum computation. In this topological' regime of well-separated MZMs, their overlap is exponentially small, leading to exponentially small Majorana splitting, thus enabling the MZMs to be topologically protected by the superconducting gap. In real experimental samples, however, the existence of disorder and the finite length of the 1D wire considerably complicates the situation leading to ambiguities in defining topology’ since the Majorana splitting between the two end modes may not necessarily be small in disordered wires of short length. We theoretically study this situation by calculating the splitting in experimentally relevant short disordered wires, and explicitly investigating the applicability of the `exponential protection’ constraint as a function of disorder, wire length, and other system parameters. We find that the exponential regime is highly constrained, and is suppressed for disorder somewhat less than the topological superconducting gap. We provide detailed results and discuss the implications of our theory for the currently active experimental search for MZMs in superconductor-semiconductor hybrid platforms.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 pages, 14 figures
Robustness of real-space topology in moiré systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Kryštof Kolář, Kang Yang, Felix von Oppen, Christophe Mora
The appearance of fractional Chern insulators in moiré systems can be rationalized by the presence of a fictitious magnetic field associated with the spatial texture of layer-resolved electronic wavefunctions. Here, we present a systematic study of real-space topology and the associated fictitious magnetic fields in moiré systems. We first show that at the level of individual Bloch wavefunctions, the real-space Chern number, akin to a Pontryagin index, is a fragile marker. It generically vanishes except for specific limits where the Bloch functions exhibit fine-tuned zeroes within the unit cell, such as the chiral limit of twisted bilayer graphene (TBG) or the adiabatic regime of twisted homobilayer transition metal dichalcogenides (TMD). We then show that these limitations do not apply to textures associated with ensembles of Bloch wavefunctions, such as entire bands or the ensemble of states at a given energy. The Chern number of these textures defines a robust topological index protected by a spectral gap. We find that symmetries constrain it to be nonzero for both twisted TMDs and TBG across all twist angles and levels of corrugation, implying experimental signatures in scanning tunneling microscopy measurements. We also study real-space topology within the topological heavy fermion model of TBG, finding that the real-space topological features are supported only by the light c-electrons.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Identifying Anyonic Topological Order in Fractional Quantum Anomalous Hall Systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Recently observed fractional quantum anomalous Hall materials (FQAH) are candidates for topological quantum hardware, but their required anyon states are elusive. We point out dependence on monodromy in the fragile band topology in 2-cohomotopy. An algebro-topological theorem of Larmore & Thomas (1980) then identifies FQAH anyons over momentum space. Admissible braiding phases are 2C-th roots of unity, for C the Chern number. This lays the foundation for understanding symmetry-protected topological order in FQAH systems, reducing the problem to computations in equivariant cohomotopy.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Mathematical Physics (math-ph), Algebraic Topology (math.AT), Quantum Physics (quant-ph)
4+2 pages, a couple of figures
Mixed valence Mott insulator and composite excitation in twisted bilayer graphene
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Jing-Yu Zhao, Boran Zhou, Ya-Hui Zhang
Interplay of strong correlation and flat topological band has been a central problem in moiré systems such as the magic angle twisted bilayer graphene (TBG). Recent studies show that Mott-like states may still be possible in TBG despite the Wannier obstruction. However, the nature of such unconventional states is still not well understood. In this work we construct the ground state wavefunction and exotic excitations of a symmetric correlated semimetal or insulator at even integer filling using a parton mean field theory of the topological heavy fermion model. We label the valence of the $ f$ orbital based on its occupation $ n_f$ . At $ \nu=-2$ , we show that the $ f$ orbital is not in the simple $ f^{2+}$ valence expected from a trivial Mott localization. Instead, around $ 1/3$ of AA sites are self doped, with holes entering the $ c$ orbitals away from AA sites. As a result, the $ f$ orbital is in a superposition of $ f^{2+}$ and $ f^{3+}$ valences and should not be viewed as local moment. We dub the phase as \textit{mixed valence Mott insulator}. This unconventional insulator has a large hybridization $ \langle c^\dagger f \rangle\neq 0$ and is sharply distinct from the usual kondo breakdown' picture. In most of the momentum space away from the $ \Gamma$ point, there is a Mott gap equal to the Hubbard $ U$ . At the $ \Gamma$ point, we have a charge transfer gap’ much smaller than $ U$ . In particular, the top of the lower band is dominated by a composite excitation, which is a linear combination of $ |f^{1+}\rangle\langle f^{2+}|$ and $ |f^{2+}\rangle\langle f^{3+}|$ with a sign structure such that it is orthogonal to the microscopic $ f$ operator. At $ \nu=0$ , similar approach leads to a Mott semimetal. We hope this work will inspire more explorations of the Anderson models with a large hybridization, a regime which may host new physics beyond the familiar Kondo or heavy fermion systems.
Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 10 figures
Superconductivity via paramagnon and magnon exchange in a 2D near-ferromagnetic full metal and ferromagnetic half-metal
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-02 20:00 EDT
Zachary M Raines, Andrey V Chubukov
We study superconductivity in paramagnetic and ferromagnetically-ordered phases in a two-dimensional electron system with parabolic fermionic dispersion and short-range repulsive interaction. In the paramagnetic phase, we find that a weak momentum dependence of a paramagnon propagator parametrically reduces the onset temperature for the pairing compared to that in phenomenological theories which assume a strong dispersion of a paramagnon and also changes the topology of the gap function. In the ferromagnetic phase, we show that the order instantly polarizes low-energy fermionic excitations. We derive the fully renormalized pairing interaction between low-energy fermions, mediated by two transverse Goldstone modes and show that it is attractive in a spatially-odd channel. The pairing temperature in the ferromagnetic phase is found to be a fraction of the Fermi energy, significantly larger than in the paramagnetic phase near the transition. Our results are relevant for understanding superconductivity in proximity to itinerant ferromagnetism in multi-valley graphene systems, particularly the ones with full valley and spin polarization.
Superconductivity (cond-mat.supr-con)
13 pages, 13 figures
Superconductivity induced by spin-orbit coupling in a two-valley ferromagnet
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-02 20:00 EDT
Zachary M Raines, Andrey V Chubukov
We analyze the origin of superconductivity in a ferromagnetically ordered state of multi-layer graphene systems placed in proximity to WSe$ _2$ . We model these materials by a two-valley system of interacting fermions with small pockets and Ising spin-orbit coupling. The model yields a canted ferromagnetic order, which gives rise to a half-metal. We obtain the magnon spectrum and derive two sets of magnon-mediated 4-fermion interactions: spin-flip interactions mediated by a single magnon and spin-preserving interactions mediated by two magnons. We argue that both processes have to be included on equal footing into the magnon-mediated pairing interaction between low-energy fermions from the filled bands. Then the full magnon-mediated interaction satisfies Adler criterion and for a valley-odd/spatially-even order parameter contains a universal attractive piece. This term is induced by spin-orbit coupling and is confined to energies which are parametrically smaller than the Fermi energy. We argue that, due to retardation, this magnon-mediated attraction gives rise to superconductivity despite that there exists a stronger static repulsion, in close analogy with how phonon-mediated attraction gives rise to pairing in the presence of stronger Coulomb (Hubbard) repulsion.
Superconductivity (cond-mat.supr-con)
6 pages, 4 figures
Electronic structure and optical absorption of armchair graphene/boron nitride lateral heterostructures from first principles and models
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Elisa Serrano Richaud, Sylvain Latil, Lorenzo Sponza
We investigate the electronic and optical properties of lateral heterostructures made of alternated armchair ribbons of graphene and hexagonal boron nitride. We employ ab initio theories (DFT and the G0W0 method) as well as a tight-binding ladder model originally introduced to study the gapwidth of isolated nanoribbons. After investigating the charge distribution across the interface, we identify the nature of the states around the gap and scrutinize their evolution as a function of the characteristic dimensions of the system (the graphene ribbons’ width N and the boron nitride ribbons’ width L). We also disclose how the very interface between graphene and boron nitride changes the electronic properties of both materials with respect to the corresponding isolated nanoribbons. Finally we discuss the light absorption properties of these systems by deriving specific selection rules for the heterostructures and calculating spectra from first principles in the independent particle and the random phase approximations
Materials Science (cond-mat.mtrl-sci)
Kibble-Zurek dynamics across the first-order quantum transitions of quantum Ising chains in the thermodynamic limit
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-02 20:00 EDT
Andrea Pelissetto, Davide Rossini, Ettore Vicari
We study the out-of-equilibrium Kibble-Zurek (KZ) dynamics in quantum Ising chains in a transverse field, driven by a time-dependent longitudinal field $ h(t)=t/t_s$ ($ t_s$ is the time scale of the protocol), across their first-order quantum transitions (FOQTs) at $ h=0$ . The KZ protocol starts at time $ t_i<0$ from the negatively magnetized ground state for $ h_i = t_i/t_s<0$ . Then, the system evolves unitarily up to a time $ t_f > 0$ , such that the magnetization of the state at time $ t_f$ is positive. In finite-size systems, the KZ dynamics develops out-of-equilibrium finite-size scaling (OFSS) behaviors. Their scaling variables depend either exponentially or with a power law on the size, depending on the boundary conditions (BC). The OFSS functions can be computed in effective models restricted to appropriate low-energy (magnetized and/or kink) states. The KZ scaling behavior drastically changes in the thermodynamic limit (TL), defined as the infinite-size limit keeping $ t$ and $ t_s$ fixed, which appears substantially unrelated with the OFSS regime, because it involves higher-energy multi-kink states, which are irrelevant in the OFSS limit. The numerical analyses of the KZ dynamics in the TL show the emergence of a quantum spinodal-like scaling behavior at the FOQTs for all considered BC, which is independent of the BC. The longitudinal magnetization changes sign at $ h(t)=h\ast>0$ , where $ h\ast$ decreases with increasing $ t_s$ , as $ h\ast\sim 1/\ln t_s$ . Moreover, in the large-$ t_s$ limit, the time-dependence of the magnetization is described by a universal function of $ \Omega = t/\tau_s$ , with $ \tau_s = t_s/\ln t_s$ .
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
19 pages
Deformation band patterns and dislocation structures in finite strain crystal viscoplasticity
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Deformation band patterning in single crystals is investigated using a finite strain crystal viscoplasticity model based on the evolution of dislocation densities. In the presence of strong latent hardening and weak rate dependence, the deformation organizes into laminate microstructures consisting of single-slip regions separated by dislocation walls. The influence of material and numerical parameters on the nucleation and morphology of these patterns is analyzed in 2D single crystals under plane strain compression. Pattern formation is also observed in 3D single-crystal cylinders subjected to tension, where the characteristic size of deformation microstructures is found to depend on mesh size and boundary conditions in the absence of an intrinsic material length scale. To address this limitation, strain gradient plasticity is introduced, providing a length scale that governs the size of the patterns. Finally, we demonstrate that deformation patterns and dislocation structures also emerge in 2D and 3D polycrystals, highlighting the generality of the phenomenon.
Materials Science (cond-mat.mtrl-sci)
Gliding microtubules exhibit tunable collective rotation driven by chiral active forces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Madhuvanthi Guruprasad Athani, Nathan Prouse, Niranjan Sarpangala, Patrick Noerr, Guillaume Schiano-Lomoriello, Ankush Gargeshwari Kumar, Fereshteh L. Memarian, Jeremie Gaillard, Laurent Blanchoin, Linda S. Hirst, Kinjal Dasbiswas, Ajay Gopinathan, Ondřej Kučera, Daniel A. Beller
How chirality propagates across scales remains an open question in many biological and synthetic systems. An especially clear manifestation of this propagation is found in in vitro gliding assays of cytoskeletal filaments on surfaces, driven by molecular motors. These assays have become model systems of active matter dynamics, as they spontaneously organize into diverse dynamical states, including collective motions with chiral rotation. However, the microscopic mechanisms underlying these chiral collective dynamics have remained unclear. Here, we investigate rotating active nematic order in microtubule gliding assay experiments under two stabilization conditions, each on two types of substrates. We propose that chirality in active forces exerted by motors on microtubules represents a viable mechanism for this large-scale chirality. Using Brownian dynamics simulations of self-propelled, semiflexible filaments with chiral activity, we demonstrate that coherently rotating active nematic order emerges by this mechanism even in the absence of curvature, i.e. shape chirality, of the constituent filaments. Moreover, we predict that the angular speed and handedness of the collective rotation can be tuned by modulating filament stiffness. Our findings identify a new set of sufficient microscopic ingredients for predictable propagation of chiral handedness from the molecular to the material scale in living and active matter.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
29 pages, 19 figures. Supplementary movies available at this https URL
Temperature chaos as a logical consequence of reentrant transition in spin glasses
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-02 20:00 EDT
Hidetoshi Nishimori, Masayuki Ohzeki, Manaka Okuyama
Temperature chaos is a striking phenomenon in spin glasses, where even slight changes in temperature lead to a complete reconfiguration of the spin state. Another intriguing effect is the reentrant transition, in which lowering the temperature drives the system from a ferromagnetic phase into a less ordered spin-glass or paramagnetic phase. In the present paper, we reveal an unexpected connection between these seemingly unrelated phenomena in the finite-dimensional Edwards-Anderson model of spin glasses by introducing a generalized formulation that incorporates correlations among disorder variables. Assuming the existence of a spin glass phase at finite temperature, we establish that temperature chaos arises as a logical consequence of reentrance in the Edwards-Anderson model. Our findings uncover a previously hidden mathematical structure relating reentrance and temperature chaos, offering a new perspective on the physics of spin glasses beyond the mean-field theory.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
13 pages, 11 figures
Triplet nodal lines and Chern bands in XCuCl$_{3}$ (X= K, Tl)
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Charles B. Walker, Matthew Stern, Judit Romhányi
We investigate the symmetry-enforced line nodes of the triplet excitations of XCuCl$ _{3}$ (X= K, Tl), showing that they are protected by the nonsymmorphic symmetries and are unaffected by the microscopic details, such as interaction and anisotropy strength, as long as the ground state and the symmetry group remain unaltered. Extending the conventionally used isotropic spin model for XCuCl$ _{3}$ , our analysis includes all the symmetry-allowed anisotropies and gives a detailed account of the role they play in the band topology of triplets. We show that the triplet line nodes carry nontrivial Berry phases and compute their $ Z_2$ topological indices. To investigate the effect of breaking the nonsymmorphic symmetry protecting the triplet nodes, we apply a magnetic field tilted away from the high symmetry $ (010)$ axis. We find that while the g-tensor anisotropy behaves as a trivial mass gapping out the triplets, exchange anisotropies supply a nontrivial momentum-dependent mass term. Analogous to Haldane’s original model, the competition of these mass terms determines the nature of the band topology in XCuCl$ _{3}$ . To enable an analytic study of the band topology we derive an effective Dirac Hamiltonian and validate it by computing the band structure and topological indices in the nodal line and gapped phases from the linear bond-wave formalism.
Strongly Correlated Electrons (cond-mat.str-el)
17 pages, 8 figures
Homotopy continuation method for solving Dyson equation fully self-consistently: theory and application to NdNiO2
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Solution of the Dyson equation for the small-gap systems can be plagued by large non-converging iterations. In addition to the convergence issues, due to a high non-linearity, the Dyson equation may have multiple solutions. We apply the homotopy continuation approach to control the behavior of iterations. We used the homotopy continuation to locate multiple fully self-consistent GW solutions for NdNiO2 solid and to establish the corresponding Hartree-Fock limits. Some of the solutions found are qualitatively new and help to understand the nature of electron correlation in this material. We show that there are multiple low-energy charge-transfer solutions leading to a formation of charge-density waves. Our results qualitatively agree with the experimental conductivity measurements. To rationalize the structure of solutions, we compare the k-point occupations and generalize the concept of natural difference orbitals for correlated periodic solids.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con), Chemical Physics (physics.chem-ph)
Topology-ferrimagnetism intertwining via weak interactions in Lieb lattices
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-02 20:00 EDT
Lei Chen, Bei-Bei Wang, Jianmin Yuan, Long Zhang, Jinsen Han, Yongqiang Li
A common wisdom about quantum many-body systems is that emergent phases typically fall into either the Landau-Ginzburg paradigm or topological classifications. Experimentally realizing the intertwined emergence of spontaneous symmetry breaking and topological order remains challenging. Here, we present an experimentally accessible platform for studying magnetic topological states in a spin-orbit-coupled Lieb lattice. Remarkably, we observe the coexistence of topological characteristics, quantified by the Chern number and Bott index, with spontaneous symmetry-breaking orders, such as ferrimagnetism, in the many-body ground states. Computational analyses combining dynamical mean-field theory and Hartree-Fock approximations reveal a pronounced parameter regime where magnetic topological insulators emerge even under weak interactions. This unconventional phenomenon originates from the Lieb lattice’s unique band structure, which facilitates the synergy between interaction-driven symmetry breaking and spin-orbit coupling induced band inversion. Crucially, spin polarization and spin winding co-emerge as inherently coupled phenomena due to their shared origin in the same interacting, spinful atoms. We further propose a specific experimental implementation scheme for ultracold atoms, utilizing currently available Raman lattice techniques. Our findings pave the way for exploring the interplay between symmetry-broken states and topological order in strongly correlated systems.
Quantum Gases (cond-mat.quant-gas)
Engineering NV Centers via Hydrogen-Driven Defect Chemistry in CVD Diamonds for Quantum Applications: NVHx Dissociations into NV, Origin of 468nm Center, and Cause of Brown Coloration
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Mubashir Mansoor, Kamil Czelej, Sally Eaton-Magaña, Mehya Mansoor, Rümeysa Salci, Maryam Mansoor, Taryn Linzmeyer, Yahya Sorkhe, Kyaw S. Moe, Ömer Özyildirim, Kouki Kitajima, Mehmet Ali Sarsil, Taylan Erol, Gökay Hamamci, Onur Ergen, Adnan Kurt, Arya Andre Akhavan, Zuhal Er, Sergei Rubanov, Nikolai M. Kazuchits, Aisha Gokce, Nick Davies, Servet Timur, Steven Prawer, Alexander Zaitsev, Mustafa Ürgen
Achieving high NV center conversion efficiency remains a key challenge in advancing diamond-based quantum technologies. The generally accepted mechanism for NV formation is that irradiation-induced vacancies become mobile during annealing and are trapped by substitutional nitrogen. However, the suggested mechanism does not consider the presence and role of hydrogen in the diamond and its influence on the NV formation pathway. This is despite ab-initio calculations, which strongly suggest the formation of hydrogen-passivated NV centers during CVD diamond growth. Recent experimental observations showing a strong spatial correlation between NV centers, brown coloration, and the 468 nm luminescence center in as-grown CVD diamonds prompted us to investigate the atomistic origin of these phenomena in the presence of NxVHy-type complex defects. We used hybrid density functional theory DFT calculations and spectroscopic analysis of CVD diamonds grown with varying nitrogen content to investigate defect equilibria during growth. We identified the 468 nm center as the NVH- defect, a hydrogen-passivated NV center, and assigned the characteristic UV-VIS absorption bands at 270 360 and 520 nm to NxVHy complexes. Our findings reveal that hydrogen plays a central role in stabilizing these defects during growth. We further showed that NVHx complex defects dissociate into NV centers and interstitial hydrogen during post-growth irradiation and annealing, complementing vacancy trapping by substitutional nitrogen. These results provide a unified picture of the defect chemistry underlying brown coloration, 468 nm center, and NV formation in CVD diamonds, offering new insights for optimizing diamond synthesis and processing for quantum applications by taking advantage of hydrogens role and dissociation of NVHx complexes.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph), Computational Physics (physics.comp-ph)
Preprint, 56 pages, 15 figures, 1 table
Phase field dislocation dynamics study of grain boundary-dislocation interactions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Brayan Murgas, Avanish Mishra, Nithin Mathew, Abigail Hunter
A new phase field dislocation dynamics formulation is presented, which couples micromechanical solvers and the time-dependent Ginzburg-Landau equation. Grain boundary (GB)-dislocation interactions are studied by describing GBs as inclusions. Grain boundary properties are computed from Molecular Statics simulations and an additional contribution to the total energy that takes into account the GB energy is considered in the calculations. Interaction of a screw dislocation with minimum energy and metastable states of low and high angle $ \langle$ 110$ \rangle$ symmetric tilt grain boundaries are studied. We show good agreement between predictions from our phase field dislocation dynamics formulation and molecular dynamics simulations of grain boundary-dislocation interactions.
Materials Science (cond-mat.mtrl-sci)
Main text 27 pages, entire text 49 pages
Termination-Dependent Resistive Switching in SrTiO$_3$ Valence Change Memory Cells
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Marko Mladenović, Manasa Kaniselvan, Christoph Weilenmann, Alexandros Emboras, Mathieu Luisier
Valence change memory (VCM) cells based on SrTiO$ _3$ (STO), a perovskite oxide, are a promising type of emerging memory device. While the operational principle of most VCM cells relies on the growth and dissolution of one or multiple conductive filaments, those based on STO are known to exhibit a distinctive, ‘interface-type’ switching, which is associated with the modulation of the Schottky barrier at their active electrode. Still, a detailed picture of the processes that lead to interface-type switching is not available. In this work, we use a fully atomistic and ab initio model to study the resistive switching of a Pt-STO-Ti stack. We identify that the termination of the crystalline STO plays a decisive role in the switching mechanism, depending on the relative band alignment between the material and the Pt electrode. In particular, we show that the accumulation of oxygen vacancies at the Pt side can be at the origin of resistive switching in TiO$ _2$ -terminated devices by lowering the conduction band minimum of the STO layer, thus facilitating transmission through the Schottky barrier. Moreover, we investigate the possibility of filamentary switching in STO and reveal that it is most likely to occur at the Pt electrode of the SrO-terminated cells.
Materials Science (cond-mat.mtrl-sci)
Quenching of excitons at grain boundaries in C60 thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Rysa Greenwood, Bradley G. Guislain, MengXing Na, Alexandra B. Tully, Sergey Zhdanovich, Jerry Icban Dadap, Sydney K. Y. Dufresne, Vanessa King, Jiabin Yu, Giorgio Levy, Arthur K. Mills, Matteo Michiardi, Andrea Damascelli, Sarah A. Burke, David J. Jones
Exciton lifetimes play a critical role in the performance of organic optoelectronic devices. In this work, we investigate how the presence of multiple rotational domains, and therefore grain boundaries, impacts exciton dynamics in thin films of C60/Au(111) using time and angle-resolved photoemission spectroscopy (TR-ARPES). We find that films with multiple rotational domains exhibit shorter exciton lifetimes and evidence of exciton-exciton annihilation, even when one domain predominates. Scanning tunneling microscopy (STM) measurements reveal electronic structure changes resulting from a locally reduced dielectric constant at grain boundaries, providing a mechanism for lifetime reduction through exciton funneling and other additional decay channels. These findings highlight the critical role of film quality in determining intrinsic exciton lifetimes, and show that minuscule amounts of disorder that are nearly undetectable by ensemble measurements can significantly impact dynamics. These results imply that precise structural control is essential for optimize the performance of organic optoelectronic devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
19 pages, 3 figures
Origami of Multi-Layered Spaced Sheets
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Guowei Wayne Tu, Evgueni T. Filipov
Two-dimensional (2D) origami tessellations such as the Miura-ori are often generalized to build three-dimensional (3D) architected materials with sandwich or cellular structures. However, such 3D blocks are densely packed with continuity of the internal material, while for many engineering structures with multi-physical functionality, it is necessary to have thin sheets that are separately spaced and sparsely connected. This work presents a framework for the design and analysis of multi-layered spaced origami, which provides an origami solution for 3D structures where multiple flat sheets are intentionally spaced apart. We connect Miura-ori sheets with sparsely installed thin-sheet parallelogram-like linkages. To explore how this connectivity approach affects the behavior of the origami system, we model the rigid-folding kinematics using analytic trigonometry and rigid-body transformations, and we characterize the elastic-folding mechanics by generalizing a reduced order bar and hinge model for these 3D assemblies. The orientation of the linkages in the multi-layered spaced origami determines which of three folding paths the system will follow including a flat foldable type, a self-locking type, and a double-branch type. When the origami is flat foldable, a maximized packing ratio and a uniform in-plane shear stiffness can be achieved by strategically choosing the link orientation. We show possible applications by demonstrating how the multi-layered spaced origami can be used to build deployable acoustic cloaks and heat shields.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Computational Physics (physics.comp-ph)
Presented at IDETC 2023 and EMI 2024
Journal of the Mechanics and Physics of Solids 190 (2024): 105730
AstroECP: towards more practical Electron Channeling Contrast Imaging
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
M. Haroon Qaiser, Lukas Berners, Robin J. Scales, Tianbi Zhang, Martin Heller, Jiri Dluhos, Sandra Korte-Kerzel, T. Ben Britton
Electron channeling contrast imaging (ECCI) is a scanning electron microscopy (SEM) based technique that enables bulk-sample characterization of crystallographic defects (e.g. dislocations, stacking faults, low angle boundaries). Despite its potential, ECCI remains underused for quantitative defect analysis as compared to transmission electron microscope (TEM) based methods. Here, we overcome barriers that limit the use of ECCI including optimizing signal-to-noise contrast, precise determination of the incident beam vector with calibrated and easy to use simulations and experimental selected area electron channeling patterns (SA-ECP). We introduce a systematic ECCI workflow, alongside a new open-source software tool (AstroECP), that includes calibration of stage tilting, SA-ECP field of view, and the energy that forms the ECP/ECCI contrast using dynamical simulations. The functionality of this workflow is demonstrated with case studies that include threading dislocations in GaAs and the cross validation of precession based ECCI-contrast, which is otherwise known as Electron Channeling Orientation Determination (eCHORD). To assist the reader, we also provide best practice guidelines for ECCI implementation to promote high-resolution defect imaging in the SEM.
Materials Science (cond-mat.mtrl-sci), Instrumentation and Detectors (physics.ins-det)
as submitted version
Femtosecond photocurrents by the Dresselhaus bulk spin-galvanic effect in an inversion-asymmetric ferromagnet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Junwei Tong, Zdenek Kaspar, Afnan Alostaz, Reza Rouzegar, Chihun In, Tim Titze, Maximilian Staabs, Genaro Bierhance, Yanzhao Wu, Holger Grisk, Jakob Walowski, Markus Münzenberg, Felicitas Gerhard, Johannes Kleinlein, Tobias Kießling, Charles Gould, Laurens W. Molenkamp, Xianmin Zhang, Daniel Steil, Tom S. Seifert, Tobias Kampfrath
We study ultrafast photocurrents in thin films of a model ferromagnetic metal with broken bulk inversion symmetry, the half-metallic Heusler compound NiMnSb, following excitation with an optical pump pulse with photon energy 1.55 eV. Remarkably, in terms of the direction of the sample magnetization M, all photocurrents are found to be a superposition of a component with Rashba- and Dresselhaus-type symmetry. We explain the Dresselhaus bulk photocurrent as follows: Pump-induced electron heating induces an excess of spin {\mu}_s||M, which transfers spin angular momentum into states with Dresselhaus-type spin-momentum locking. The resulting charge current relaxes on a time scale of 10 fs by momentum relaxation and, thus, follows {\mu}_s quasi-instantaneously. The relaxation of {\mu}_s is governed by the cooling of the electrons and not by the significantly slower spin-lattice relaxation of half-metals. Our findings add the Dresselhaus spin-galvanic effect (SGE) to the set of ultrafast spin-charge-conversion phenomena. They indicate a route to more efficient spintronic terahertz emitters and detectors based on the volume scaling of the bulk SGE.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
14 pages, 4 figures
Generation of Pure Spin Current with Insulating Antiferromagnetic Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Yingwei Chen, Junyi Ji, Liangliang Hong, Xiangang Wan, Hongjun Xiang
The generation of pure spin currents is critical for low-dissipation spintronic applications, yet existing methods relying on spin-orbit coupling or ferromagnetic interfaces face challenges in material compatibility and operational robustness. We propose a paradigm-shifting approach to generate symmetry-protected pure spin currents by applying mechanical stress on insulating antiferromagnetic materials, i.e., the pure piezospintronic effect. We first classify magnetic point groups enabling pure piezospintronic effects. A novel first-principles method is developed to compute the spin dipole moments and coefficients of the piezospintronic effect. Integrating these methodologies with high-throughput screening, we identify FeOOH, Cr2O3 and NaMnX (X=As, Bi, P, Sb) with significant pure piezospintronic effects. Interestingly, we reveal that the ionic displacement contribution dominates the piezospintronic effect, in contrast to the piezoelectric effect. Our study not only provides first-principles approach for investigating spin dipole moment related phenomena (e.g., ferrotoroidicity, fractional quantum spin dipole moment, piezospintronics), but also provide promising piezospintronic materials for experimental verification and industrial applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Complete Boundary Phase Diagram of the Spin-$\frac{1}{2}$ XXZ Chain with Boundary Fields in the Anti-Ferromagnetic Gapped Regime
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Parameshwar R. Pasnoori, Yicheng Tang, Junhyun Lee, J. H. Pixley, Patrick Azaria, Natan Andrei
We consider the spin $ \frac{1}{2}$ XXZ chain with diagonal boundary fields and solve it exactly using Bethe ansatz in the gapped anti-ferromagnetic regime and obtain the complete phase boundary diagram. Depending on the values of the boundary fields, the system exhibits several phases which can be categorized based on the ground state exhibited by the system and also based on the number of bound states localized at the boundaries. We show that the Hilbert space is comprised of a certain number of towers whose number depends on the number of boundary bound states exhibited by the system. The system undergoes boundary phase transitions when boundary fields are varied across certain critical values. There exist two types of phase transitions. In the first type the ground state of the system undergoes a change. In the second type, named the `Eigenstate phase transition’, the number of towers of the Hilbert space changes, which is again associated with the change in the number of boundary bound states exhibited by the system. We use the DMRG and exact diagonalization techniques to probe the signature of the Eigenstate phase transition and the ground state phase transition by analyzing the spin profiles in each eigenstate.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
arXiv admin note: substantial text overlap with arXiv:2212.14832
Enhancing ferroelectric stability: Wide-range of adaptive control in epitaxial HfO2/ZrO2 superlattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Jingxuan Li, Shiqing Deng, Liyang Ma, Yangyang Si, Chao Zhou, Kefan Wang, Sizhe Huang, Jiyuan Yang, Yunlong Tang, Yu-Chieh Ku, Chang-Yang Kuo, Yijie Li, Sujit Das, Shi Liu, Zuhuang Chen
The metastability of the polar phase in HfO2, despite its excellent compatibility with the complementary metal-oxide-semiconductor process, remains a key obstacle for its industrial applications. Traditional stabilization approaches, such as doping, often induce crystal defects and impose constraints on the thickness of ferroelectric HfO2 thin films. These limitations render the ferroelectric properties vulnerable to degradation, particularly due to phase transitions under operational conditions. Here, we demonstrate robust ferroelectricity in high-quality epitaxial (HfO2)n/(ZrO2)n superlattices, which exhibit significantly enhanced ferroelectric stability across an extended thickness range. Optimized-period superlattices maintain stable ferroelectricity from up to 100 nm, excellent fatigue resistance exceeding 109 switching cycles, and a low coercive field of ~0.85 MV/cm. First-principles calculations reveal that the kinetic energy barrier of phase transition and interfacial formation energy are crucial factors in suppressing the formation of non-polar phases. This work establishes a versatile platform for exploring high-performance fluorite-structured superlattices and advances the integration of HfO2-based ferroelectrics into a broader range of applications.
Materials Science (cond-mat.mtrl-sci)
25pages, 4 figures
Second-order microscopic nonlinear susceptibility in a centrosymmetric material: application to imaging valence electron motion
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Chance Ornelas-Skarin, Tatiana Bezriadina, Matthias Fuchs, Shambhu Ghimire, J. B. Hastings, Quynh L Nguyen, Gilberto de la Peña, Takahiro Sato, Sharon Shwartz, Mariano Trigo, Diling Zhu, Daria Popova-Gorelova, David A. Reis
We report measurements of phase-matched nonlinear x-ray and optical sum-frequency generation from single-crystal silicon using sub-resonant 0.95 eV laser pulses and 9.5 keV hard x-ray pulses from the LCLS free-electron laser. The sum-frequency signal appears as energy and momentum sidebands to the elastic Bragg peak. It is proportional to the magnitude squared of the relevant temporal and spatial Fourier components of the optically induced microscopic charges/currents. We measure the first- and second-order sideband to the 220 Bragg peak and find that the efficiency is maximized when the applied field is along the reciprocal lattice vector. For an optical intensity of $ \sim10^{12} \text{W}/\text{cm}^2$ , we measure peak efficiencies of $ 3\times 10^{-7}$ and $ 3\times 10^{-10}$ for the first and second-order sideband respectively (relative to the elastic Bragg peak). The first-order sideband is consistent with induced microscopic currents along the applied electric field (consistent with an isotropic response). The second-order sideband depends nontrivially on the optical field orientation and is consistent with an anisotropic response originating from induced charges along the bonds with C$ _{3v}$ site symmetry. The results agree well with first-principles Bloch-Floquet calculations.
Materials Science (cond-mat.mtrl-sci)
Process-aware and high-fidelity microstructure generation using stable diffusion
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Hoang Cuong Phan, Minh Tien Tran, Chihun Lee, Hoheok Kim, Sehyok Oh, Dong-Kyu Kim, Ho Won Lee
Synthesizing realistic microstructure images conditioned on processing parameters is crucial for understanding process-structure relationships in materials design. However, this task remains challenging due to limited training micrographs and the continuous nature of processing variables. To overcome these challenges, we present a novel process-aware generative modeling approach based on Stable Diffusion 3.5 Large (SD3.5-Large), a state-of-the-art text-to-image diffusion model adapted for microstructure generation. Our method introduces numeric-aware embeddings that encode continuous variables (annealing temperature, time, and magnification) directly into the model’s conditioning, enabling controlled image generation under specified process conditions and capturing process-driven microstructural variations. To address data scarcity and computational constraints, we fine-tune only a small fraction of the model’s weights via DreamBooth and Low-Rank Adaptation (LoRA), efficiently transferring the pre-trained model to the materials domain. We validate realism using a semantic segmentation model based on a fine-tuned U-Net with a VGG16 encoder on 24 labeled micrographs. It achieves 97.1% accuracy and 85.7% mean IoU, outperforming previous methods. Quantitative analyses using physical descriptors and spatial statistics show strong agreement between synthetic and real microstructures. Specifically, two-point correlation and lineal-path errors remain below 2.1% and 0.6%, respectively. Our method represents the first adaptation of SD3.5-Large for process-aware microstructure generation, offering a scalable approach for data-driven materials design.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
46 pages, 13 figures, 5 tables, 3rd Word Congress on Artificial Intelligence in Materials & Manufacturing 2025
Effects of Antisite Defects on Seebeck Coefficient in Fe_2VAl – Analyses based on Bipolar Random Anderson Model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Takami Tohyama, Hidetoshi Fukuyama
A microscopic mechanism is proposed for a dramatic sign change of the Seebeck coefficient from positive to negative sign by the introduction of antisite defects in Fe$ _2$ VAl based on bipolar random Anderson model (BPRAM), which incorporates hybridization effects between randomly distributed antisites and host bands, where the valence and conduction bands are treated separately due to their separation in momentum space. Applying a self-consistent T-matrix approximation, we find that antisite defects in Fe$ _2$ VAl induce new states in the band overlap region, resulting in a scattering rate that is higher for hole carriers in the valence band than that for electron carriers in the conduction band, leading to negative Seebeck coefficient. This mechanism of sign change presents a potential new approach for controlling thermoelectric properties in semimetallic systems without changing carrier concentration.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 8 figures
Influence of oxygen-defects on intraband terahertz conductivity of carbon nanotubes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Maksim Paukov, Shuang Sun, Dmitry Krasnikov, Arina Radivon, Gennady Komandin, Andrey Vyshnevyy, Emil Chiglintsev, Stanislav Colar, Kirill Brekhov, Kirill Zaytsev, Sergei Garnov, Nadzeya Valynets, Albert Nasibulin, Aleksey Arsenin, Valentyn Volkov, Alexander Chernov, Yan Zhang, Maria Burdanova
The exceptional charge transport properties of single-walled carbon nanotubes (SWCNTs) enable numerous ultrafast optoelectronic applications. Modifying SWCNTs by introducing defects significantly impacts the performance of nanotube-based devices, making defect characterization crucial. This research tracked these effects in oxygen plasma-treated SWCNT thin films. Sub-picosecond electric fields of varying strengths and additional photoexcitation were used to assess how defects influence charge carrier transport. Changes in effective conductivity within the terahertz (THz) range were found to be strongly dependent on impurity levels. The plasmon resonance shift to higher THz frequencies aligns with the defect-induced reduction in conductivity and slowed carrier migration within the network. An increase in THz field strength resulted in diminished conductivity due to intraband absorption bleaching. To address the emergence of hot charge carriers, a modified Drude model, which considers non-equilibrium charge carrier distribution via fielddependent scattering rates, was applied. The dominant charge-impurity scattering rate in plasma-treated samples corresponded with an increase in defects. Additionally, the impact of defects on charge carrier dynamics on a picosecond timescale was examined. The modeled plasma-treated SWCNTs wire-grid polarizer for the THz range reveals the potential for multi-level engineering of THz devices to customize properties through controlled defect populations.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Extracting Contact Forces in Cohesive Granular Ensembles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Abrar Naseer, Karen E. Daniels, Tejas G. Murthy
Interparticle cohesion is prevalent in stored powders, geological formations, and infrastructure engineering, yet a comprehensive understanding of the effects of its micro-mechanics on bulk properties has not been established experimentally. One challenge has been that while photoelasticy has been widely and successfully used to measure the vector contact forces within dry granular systems, where the particle-particle interactions are solely frictional and compressive in nature, it has seen little development in systems where tensile forces are present. The key difficulty has been the inability to distinguish between compressive and tensile forces, which appear identically within the photoelastic response.
Here, we present a novel approach which solves this problem, by an extension to the open-source PeGS (Photoelastic Grain Solver) software available at this https URL. Our new implementation divides the procedure of finding vector contact forces into two steps: first evaluating the vector contact forces on the non-cohesive particles present in the ensemble, followed by using an equilibrium constraint to solve for the forces in the bonded particles. We find that in the dilute limit, for up to 25% bonded dimers, we can solve for all forces since each particle has only one force bearing contact that can potentially transmit tensile forces. While the case of dimers is an idealised version of cohesive granular ensemble, it provides an important first step towards experimentally studying the micro-mechanics of cohesive granular materials.
Soft Condensed Matter (cond-mat.soft)
4 pages, 4 figures, submitted in Powders and Grains Conference and the review is pending
Efficient GPU-Accelerated Training of a Neuroevolution Potential with Analytical Gradients
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-02 20:00 EDT
Hongfu Huang, Junhao Peng, Kaiqi Li, Jian Zhou, Zhimei Sun
Machine-learning interatomic potentials (MLIPs) such as neuroevolution potentials (NEP) combine quantum-mechanical accuracy with computational efficiency significantly accelerate atomistic dynamic simulations. Trained by derivative-free optimization, the normal NEP achieves good accuracy, but suffers from inefficiency due to the high-dimensional parameter search. To overcome this problem, we present a gradient-optimized NEP (GNEP) training framework employing explicit analytical gradients and the Adam optimizer. This approach greatly improves training efficiency and convergence speedily while maintaining accuracy and physical interpretability. By applying GNEP to the training of Sb-Te material systems(datasets include crystalline, liquid, and disordered phases), the fitting time has been substantially reduced-often by orders of magnitude-compared to the NEP training framework. The fitted potentials are validated by DFT reference calculations, demonstrating satisfactory agreement in equation of state and radial distribution functions. These results confirm that GNEP retains high predictive accuracy and transferability while considerably improved computational efficiency, making it well-suited for large-scale molecular dynamics simulations.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Interaction-Driven Giant Electrostatic Modulation of Ion Permeation in Atomically Small Capillaries
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Dhal Biswabhusan, Yechan Noh, Sanat Nalini Paltasingh, Chandrakar Naman, Siva Sankar Nemala, Rathi Aparna, Kaushik Suvigya, Andrea Capasso, Saroj Kumar Nayak, Li-Hsien Yeh, Kalon Gopinadhan
Manipulating the electrostatic double layer and tuning the conductance in nanofluidic systems at salt concentrations of 100 mM or higher has been a persistent challenge. The primary reasons are (i) the short electrostatic proximity length, ~3-10 Å, and (ii) difficulties in fabricating atomically small capillaries. Here, we successfully fabricate in-plane vermiculite laminates with transport heights of ~3-5 Å, which exhibit a cation selectivity close to 1 even at a 1000 mM concentration, suggesting an overlapping electrostatic double layer. For gate voltages from -2 V to +1 V, the K+-intercalated vermiculite shows a remarkable conductivity modulation exceeding 1400% at a 1000 mM KCl concentration. The gated ON/OFF ratio is mostly unaffected by the ion concentration (10-1000 mM), which confirms that the electrostatic double layer overlaps with the collective ion movement within the channel with reduced activation energy. In contrast, vermiculite laminates intercalated with Ca2+ and Al3+ ions display reduced conductance with increasing negative gate voltage, highlighting the importance of ion-specific gating effects under Å-scale confinement. Our findings contribute to a deeper understanding of electrostatic phenomena occurring in highly confined fluidic channels, opening the way to the exploration of the vast library of two-dimensional materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft), Applied Physics (physics.app-ph), Fluid Dynamics (physics.flu-dyn)
37 pages, 5 figures
Temperature dependent Resonant X-ray Inelastic Scattering at Ni L3-edge for NaNiO2 and LiNiO2
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Quentin Jacquet (1), Kurt Kummer (2), Marie Guignard (3), Elisa Grepin (4, 5 and 6), Sathiya Mariyappan (4, 5 and 6), Nicholas B. Brookes (2), Sandrine Lyonnard (1) ((1) Univ. Grenoble, Alpes, CEA, CNRS, Grenoble INP, IRIG, SyMMES, F-38000 Grenoble, France, (2) European Synchrotron Radiation Facility, F-38043 Grenoble Cedex, France, (3) Univ. Bordeaux, CNRS, Bordeaux INP, ICMCB, UMR 5026, Pessac, France, (4) Chimie du Solide-Energie, UMR 8260, College de France, Paris Cedex 05, France, (5) Sorbonne Universite, 4 Place Jussieu, Paris, France, (6) Reseau sur le Stockage Electrochimique de l Energie RS2E, France)
LiNiO2 is a promising cathode material for Li-ion battery but its atomic and electronic structure is under debate. Indeed, two sets of Ni-O distances are identified from local structural probes that are related with either Jahn-Teller distortion or bond disproportionation of NiO6 octahedra. Moreover, LiNiO2 undergoes a monoclinic to rhombohedral transition at 200 K which origin is still unclear. On the other hand, isostructural NaNiO2 shows differences from LiNiO2, as it is a well-known Jahn-Teller distorted system, and it undergoes monoclinic to rhombohedral transition at 500 K associated to the loss of the Jahn-Teller distortion. To understand better these differences, we report here Ni L3-edge Resonant inelastic X-ray scattering experiments on LiNiO2 and NaNiO2 at different temperatures (25 to 520 K) and follow the spectral changes below and above the phase transition temperatures. The observed RIXS spectra and the mapping indicate strong spectral changes for NaNiO2 confirming the disappearance of Jahn-Teller distortion during phase transition while the changes are minor for LiNiO2 suggesting very few modifications in the local structure. Theoretical simulations of RIXS spectra are required for further understanding, however, we believe that the reported dataset can be a crucial resource for developing advanced simulations that are essential to deepening our understanding of the atomic and electronic structure of these nickelates.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Charge Regulation Effect on Nanoparticles Interaction Mediated by Polyelectrolyte
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Vijay Yadav, Prabhat Kumar Jaiswal, Rudolf Podgornik, Sunita Kumari
The ability to precisely control surface charge using charged polymers is fundamental to many nanotechnology applications, enabling the design and fabrication of materials with tailored properties and functionalities. Here, we study the effect of charge regulation (CR) on the interaction between two nanoparticles (NPs) mediated by an oppositely charged polyelectrolyte (PE) in an electrolyte solution. To this end, we employ a hybrid CR Monte Carlo (CR-MC)/molecular dynamics (MD) simulation framework to systematically explore the effects of pH, salt concentration, and polymer chain length on NP surface charge behavior. For comparison, we also conduct MD simulations under constant charge (CC) conditions. Our results reveal that CR enhances PE adsorption onto NP surfaces compared to the CC case, where polymer bridging dominates across a wide range of NP intersurface separations. This enhanced adsorption under CR leads to a weak net repulsion driven by osmotic forces. In contrast, the CC model yields a stronger net attraction due to the bridging force. Furthermore, we find that the CR effects are more pronounced at a low salt concentration, whereas at a high salt concentration, counterion screening dominates in both CR and CC cases, resulting in similar interaction profiles. These findings highlight the importance of incorporating charge regulation in characterizing NP interactions within a complex biochemical environment, particularly in the presence of low salt concentrations.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
Figures 7
Dissipation engineering of fermionic long-range order beyond Lindblad
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-02 20:00 EDT
Silvia Neri, François Damanet, Andrew J. Daley, Marialuisa Chiofalo, Jorga Yago Malo
We investigate the possibility of engineering dissipatively long-range order that is robust against heating in strongly interacting fermionic systems, relevant for atoms in cavity QED. It was previously shown [Tindall et al. this http URL. 123, 030603 (2019)] that it is possible to stabilize long-range order in a Hubbard model by exploiting a dissipative mechanism in the Lindblad limit, this latter being valid for spectrally unstructured baths. Here, we first show that this mechanism still holds when including additional spin-exchange interactions in the model, that is for the tUJ model. Moreover, by means of a Redfield approach that goes beyond the Lindblad case, we show how the stability of the engineered state depends crucially on properties of the bath spectral density and discuss the feasibility of those properties in an experiment.
Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
Binding and spontaneous condensation of excitons in narrow-gap carbon nanotubes
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Giacomo Sesti, Daniele Varsano, Elisa Molinari, Massimo Rontani
Ultraclean, undoped carbon nanotubes are always insulating, even when the gap predicted by band theory is zero. The residual, observed gap is thought to have a many-body origin. Here we theoretically show that the correlated insulator is excitonic, extending our previous claim, limited to gapless (armchair) tubes [D. Varsano, S. Sorella, D. Sangalli, M. Barborini, S. Corni, E. Molinari, M. Rontani, Nature Communications $ \mathbf{8}$ , 1461 (2017)], to $ all$ narrow-gap tubes, irrespective of their size. By enhancing the two-band model with an accurate treatment of screening, validated from first principles, we derive the scaling law of the exciton binding energy with the tube radius and chirality, and compute self-consistently the fundamental transport gap of the excitonic insulator. Our findings point to the broader connection between the exciton length scale, dictated by structure, and the stability of the excitonic phase.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages and 5 figures
Many-particle hybridization of optical transitions from zero-mode Landau levels in HgTe quantum wells
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
S. Ruffenach, S. S. Krishtopenko, A. V. Ikonnikov, C. Consejo, J. Torres, X. Baudry, P. Ballet, B. Jouault, F. Teppe
We present far-infrared magnetospectroscopy measurements of a HgTe quantum well in the inverted band structure regime over the temperature range of 2 to 60 K. The particularly low electron concentration enables us to probe the temperature evolution of all four possible optical transitions originating from zero-mode Landau levels, which are split off from the edges of the electron-like and hole-like bands. By analyzing their resonance energies, we reveal an unambiguous breakdown of the single-particle picture indicating that the explanation of the anticrossing of zero-mode Landau levels in terms of bulk and interface inversion asymmetries is insufficient. Instead, the observed behavior of the optical transitions is well explained by their hybridization driven by electron-electron interaction. We emphasize that our proposed many-particle mechanism is intrinsic to HgTe quantum wells of any crystallographic orientation, including (110) and (111) wells, where bulk and interface inversion asymmetries do not induce the anticrossing of zero-mode Landau levels.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures and Supplemental materials
Plasmonic detection of Rashba spin-orbit coupling in monolayer transition-metal dichalcogenides
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Y. Li, Z. H. Tao, Y. M. Xiao, W. Xu, Q. N. Li, F. M. Peeters, D. Neilson, M. V. Milosevic
Rashba spin-orbit coupling (RSOC) induces strong momentum-dependent spin splitting and plays a crucial role in fields like spintronics and topological photonics. We here theoretically investigate the collective excitations in monolayer transition metal dichalcogenides (ML-TMDs) hosting RSOC, and conceive an approach to precisely quantify the strength of RSOC using plasmons. We determine the electron energy loss function (EELF) and plasmon dispersions for n-type ML-TMD from the dynamic dielectric function in the framework of the standard random phase approximation (RPA). In this system, both optical and acoustic plasmon modes are observed in the EELF and plasmon dispersions. Moreover, the plasmonic and spectral properties are tunable by electron density and dependent on RSOC. Crucially, we identify a minimum energy gap between the two plasmon modes to serve as a direct spectral signature of the RSOC strength. These results establish plasmons as a non-invasive, precise, and broadly tunable technique for determining RSOC in TMD van der Waals heterostructures and devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Monolayer Two-dimensional Materials Database (ML2DDB) and Applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Zhongwei Liu, Zhimin Zhang, Xuwei Liu, Mingjia Yao, Xin He, Yuanhui Sun, Xin Chen, Lijun Zhang
The discovery of two-dimensional (2D) materials with tailored properties is critical to meet the increasing demands of high-performance applications across flexible electronics, optoelectronics, catalysis, and energy storage. However, current 2D material databases are constrained by limited scale and compositional diversity. In this study, we introduce a scalable active learning workflow that integrates deep neural networks with density functional theory (DFT) calculations to efficiently explore a vast set of candidate structures. These structures are generated through physics-informed elemental substitution strategies, enabling broad and systematic discovery of stable 2D materials. Through six iterative screening cycles, we established the creation of the Monolayer 2D Materials Database (ML2DDB), which contains 242,546 DFT-validated stable structures-an order-of-magnitude increase over the largest known 2D materials databases. In particular, the number of ternary and quaternary compounds showed the most significant increase. Combining this database with a generative diffusion model, we demonstrated effective structure generation under specified chemistry and symmetry constraints. This work accomplished an organically interconnected loop of 2D material data expansion and application, which provides a new paradigm for the discovery of new materials.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Unveiling the impact of trivalent metal cation transmutation on Cs${2}$AgM(III)Cl${6}$ double perovskites using many-body perturbation theory
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Surajit Adhikari, Priya Johari
Lead-free halide double perovskites A$ _{2}$ M(I)M(III)X$ _{6}$ have garnered significant attention in the past decade as promising alternatives to CsPbX$ _{3}$ perovskites, addressing concerns related to lead toxicity and material instability. In this work, we employ a trivalent metal cation transmutation strategy to design a series of inorganic Pb-free halide double perovskites Cs$ _{2}$ AgM(III)Cl$ _{6}$ and perform a comprehensive investigation into their potential for applications in optoelectronic devices. Our first-principles calculations, rooted in density functional theory, demonstrate that these materials possess a face-centered cubic lattice structure while showcasing remarkable thermodynamic, dynamical, and mechanical stability. The G$ _{0}$ W$ _{0}$ @PBE electronic bandgap ranges from 1.47-6.20 eV, while the Bethe-Salpeter equation (BSE) indicates strong optical absorption spanning near-infrared to ultraviolet regions for these compounds. Furthermore, the excitonic properties suggest that these perovskites exhibit intermediate exciton binding energies (0.17 to 0.60 eV) and generally longer exciton lifetimes, except for the materials with M(III) = Sc, Y, Tb, and Lu. The Fröhlich model indicates that these materials exhibit intermediate to strong carrier-phonon interactions, with hole-phonon coupling more prominent than electron-phonon coupling. Interestingly, the charge-separated polaronic states are found to be less stable than the bound exciton states, with higher polaron mobility for electrons (4.92-29.03 cm$ ^{2}$ V$ ^{-1}$ s$ ^{-1}$ ) than for holes (0.56-8.69 cm$ ^{2}$ V$ ^{-1}$ s$ ^{-1}$ ) in these materials. Overall, our study demonstrates that trivalent metal cation transmutation in Cs$ _{2}$ AgM(III)Cl$ _{6}$ enables the creation of stable and lead-free halide double perovskites with exceptional, tunable optoelectronic properties, making them ideal for flexible optoelectronic applications.
Materials Science (cond-mat.mtrl-sci)
14 pages, 3 figures, 5 tables
High pressure synthesis and structural study of AuGa2 intermetallic compound
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Azkar Saeed Ahmad, Zhuoyang Yu, Sizhe Wang, Tong Weng, Wenting Lu, Baihong Sun, Jiewu Song, Qian Zhang, Martin Kunz, Bihan Wang, Elissaios Stavrou
We report the synthesis of the AuGa2 intermetallic compound, using a direct reaction of the relevant elements at room temperature and at very low pressure. The pressure needed to synthesize the AuGa2 compound is below 1 GPa, that is at the lower limit of modern large volume presses, routinely used to synthesize other commercially available materials. This study presents a new method of synthesizing AuGa2, which is much more cost efficient and environmentally friendly than the previously used high-temperature synthesis techniques, and will open new possibilities of synthesizing other intermetallic compounds using high-pressure athermal techniques.
Materials Science (cond-mat.mtrl-sci)
8 pages, 3 figures
Ab-initio-NEGF Fundamental Roadmap for Carbon-Nanotube and Two-Dimensional-Material MOSFETs at the Scaling and VDD Limit
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Using accurate Hybrid-Functional DFT coupled with the Non-Equilibrium Green’s function (NEGF) formalism, we explore and benchmark the fundamental scaling limits of CNT-FETs against Si and 2D-material MoS$ _2$ and HfS$ _2$ Nanosheets, highlighting their potential for gate length (L) and supply voltage (VDD) scaling down to 5 nm and to 0.5 V, respectively. The highest drive current is achieved by CNT-FETs with sub 1.3 nm diameters down to $ L = 9$ nm and using VDD in the 0.45-0.5V range. Below $ L = 9$ nm, however, the HfS$ _2$ NS offers the best drive and could further scale down to $ L = 5$ nm with a reduced VDD of 0.5 V.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Structural, dielectric, and ferroelectric characteristics of the low-temperature sintered 65PMN-35PT sample for electroceramic applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
B. Ramachandran, N. Sudarshan, G. Mangamma, M.S. Ramachandra Rao
A single-phase 65PMN-35PT ceramic was synthesized at a relatively low temperature (875 oC) using a modified columbite method. X-ray diffraction analysis confirmed the single-phase formation of perovskite 65PMN-35PT with a tetragonal structure. Morphological studies indicated that the sample consisted of small grains with a size of about 2 micro-m. The dielectric properties of the material demonstrate its relaxor behavior near the ferroelectric transition temperature, TC = 457 K. The saturation and remnant polarization values of approximately 25.9 and 20.1 micro-C cm-2 were achieved for an electrically poled sample. Additionally, the poling induced a negative internal electric field of about -0.2 kV cm-1 was detected due to the presence of ferroelectric nano-grains in this bulk 65PMN-35PT sample. These observed characteristics of the pyrochlore-free 65PMN-35PT ceramic are similar to those of its single-crystal counterpart.
Materials Science (cond-mat.mtrl-sci)
9 pages, 7 figures, 1 Table and Accepted for publication in Journal of Electroceramics
Generalization performance of narrow one-hidden layer networks in the teacher-student setting
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-02 20:00 EDT
Jean Barbier, Federica Gerace, Alessandro Ingrosso, Clarissa Lauditi, Enrico M. Malatesta, Gibbs Nwemadji, Rodrigo Pérez Ortiz
Understanding the generalization abilities of neural networks for simple input-output distributions is crucial to account for their learning performance on real datasets. The classical teacher-student setting, where a network is trained from data obtained thanks to a label-generating teacher model, serves as a perfect theoretical test bed. In this context, a complete theoretical account of the performance of fully connected one-hidden layer networks in the presence of generic activation functions is lacking. In this work, we develop such a general theory for narrow networks, i.e. networks with a large number of hidden units, yet much smaller than the input dimension. Using methods from statistical physics, we provide closed-form expressions for the typical performance of both finite temperature (Bayesian) and empirical risk minimization estimators, in terms of a small number of weight statistics. In doing so, we highlight the presence of a transition where hidden neurons specialize when the number of samples is sufficiently large and proportional to the number of parameters of the network. Our theory accurately predicts the generalization error of neural networks trained on regression or classification tasks with either noisy full-batch gradient descent (Langevin dynamics) or full-batch gradient descent.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Machine Learning (cs.LG), Probability (math.PR), Statistics Theory (math.ST)
34 pages, figures
Classifying soft elastic lattices using higher-order homogenization
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Basile Audoly, Claire Lestringant, Hussein Nassar
We propose a methodology for the homogenization of periodic elastic lattices that covers the case of unstable lattices, having affine (macroscopic) or periodic (microscopic) mechanisms. The singular cell problems that are encountered when a periodic mechanism is present are naturally solved by treating the amplitude $ \theta(X)$ of the mechanism as an enrichment variable. We use asymptotic second-order homogenization to derive an effective energy capturing both the strain-gradient effect $ \nabla \varepsilon$ relevant to affine mechanisms, and the $ \nabla \theta$ regularization relevant to periodic mechanisms, if any is present. The proposed approach is illustrated with a selection of lattices displaying a variety of effective behaviors. It follows a unified pattern that leads to a classification of these effective behaviors.
Soft Condensed Matter (cond-mat.soft)
Disorder induced dynamical interband response in Dirac nodal line semimetals
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
To obtain the total response of the system, the effect of disorder cannot be neglected, as it introduces a new contribution (i.e. extrinsic) in the total response of the system. In the study of dynamical (AC) effects, the interband response exhibits an exotic resonance peak due to interband transitions. Here, the dynamical interband response of Dirac nodal line semimetal is investigated by using the quantum kinetic approach. The scattering driven effect is analyzed under the first-order Born approximation (i.e., in the weak disorder limit) and reveals a resonance peak at $ 2\tilde{\mu}$ . In contrast, the field driven intrinsic response peak depends on both the mass ($ \tilde{M}$ ) and chemical potential ($ \tilde{\mu}$ ). The results indicate that the total interband response of the 3D nodal line semimetals, is mainly dominated by the disorder induced contributions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 figures
physica status solidi (RRL) Rapid Research Letters, p.2500108 (2025)
Conformational properties of strictly two-dimensional equilibrium polymers
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
J.P. Wittmer, A. Cavallo, A. Johner
Two-dimensional monodisperse linear polymer chains are known to adopt for sufficiently large chain lengths $ N$ and surface fractions $ \phi$ compact configurations with fractal perimeters. We show here by means of Monte Carlo simulations of reversibly connected hard disks (without branching, ring formation and chain intersection) that polydisperse self-assembled equilibrium polymers with a finite scission energy $ E$ are characterized by the same universal exponents as their monodisperse peers. Consistently with a Flory-Huggins mean-field approximation, the polydispersity is characterized by a Schulz-Zimm distribution with a susceptibility exponent $ \gamma=19/16$ for all not dilute systems and the average chain length $
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
14 pages,12 figures, accepted EPJE, June 2025
Twist-Tunable Spin-to-Charge Conversion and Valley-Contrasting Effects in Graphene/TMDC Heterostructures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
We consider graphene deposited on monolayers of such transition-metal dichalcogenides like MoSe$ _2$ , WSe$ _2$ , MoS$ _2$ , and WS$ _2$ . Our key objective is to study the impact of relative twist angle between the monolayers on the proximity-induced spin-orbital effects and orbital phenomena in graphene. To do this we used an effective model Hamiltonian for low-energy states, taken from available literature. The Green function formalism is used to calculate analytical formula for the spin Hall effect and nonequilibrium spin polarization in the system. We also determine the valley Hall and valley polarization effects, and their dependence on the twist angle. We have shown that the valley Hall conductivity can take the quantized value equal to $ \pm 2 e^2/h$ .
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Creep failure in heterogeneous materials from the barrier landscape
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-02 20:00 EDT
Juan Carlos Verano-Espitia, Tero Mäkinen, Mikko J. Alava, Jérôme Weiss
Stressed under a constant load, materials creep with a final acceleration of deformation and for any given applied stress and material, the creep failure time can strongly vary. We investigate creep on sheets of paper and confront the statistics with a simple fiber bundle model of creep failure in a disordered landscape. In the experiments, acoustic emission event times $ t_j$ were recorded, and both this data and simulation event series reveal sample-dependent history effects with log-normal statistics and non-Markovian behavior. This leads to a relationship between $ t_j$ and the failure time $ t_f$ with a power law relationship, evolving with time. These effects and the predictability result from how the energy gap distribution develops during creep.
Statistical Mechanics (cond-mat.stat-mech)
5 pages, 4 figures, Letter
Testing the spin-bath view of self-attention: A Hamiltonian analysis of GPT-2 Transformer
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Satadeep Bhattacharjee, Seung-Cheol Lee
The recently proposed physics-based framework by Huo and Johnson~\cite{huo2024capturing} models the attention mechanism of Large Language Models (LLMs) as an interacting two-body spin system, offering a first-principles explanation for phenomena like repetition and bias. Building on this hypothesis, we extract the complete Query-Key weight matrices from a production-grade GPT-2 model and derive the corresponding effective Hamiltonian for every attention head. From these Hamiltonians we obtain analytic \textit{phase boundaries} logit gap criteria that predict which token should dominate the next-token distribution for a given context. A systematic evaluation on 144 heads across 20 factual-recall prompts reveals a strong negative correlation between the theoretical logit gaps and the model’s empirical token rankings ($ r\approx-0.70$ , $ p<10^{-3}$ ).Targeted ablations further show that suppressing the heads most aligned with the spin-bath predictions induces the anticipated shifts in output probabilities, confirming a causal link rather than a coincidental association. Taken together, our findings provide the first strong empirical evidence for the spin-bath analogy in a production-grade model. This validation not only furnishes a tractable, physics-inspired lens for interpretability but also provides the groundwork for novel generative models, bridging the gap between theoretical condensed matter physics and AI.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG)
Structural Order Drives Diffusion in a Granular Packing
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
David Luce, Adrien Gans, Sébastien Kiesgen de Richter, Nicolas Vandewalle
We investigate how structural ordering, i.e. crystallization, affects the flow of bidisperse granular materials in a quasi-two-dimensional silo. By systematically varying the mass fraction of two particle sizes, we finely tune the degree of local order. Using high-speed imaging and kinematic modeling, we show that crystallization significantly enhances the diffusion length $ b$ , a key parameter controlling the velocity profiles within the flowing medium. We reveal a strong correlation between $ b$ and the hexatic order parameter $ \left<|\psi_6|\right>_t$ , highlighting the role of local structural organization in governing macroscopic flow behavior. Furthermore, we demonstrate that pressure gradients within the silo promote the stabilization of orientational order even in the absence of crystallization, thus intrinsically increasing $ b$ with height. These findings establish a direct link between microstructural order, pressure, and transport properties in granular silo flows.
Soft Condensed Matter (cond-mat.soft), Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
5 pages, 6 figures
A fast algorithm for 2D Rigidity Percolation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Nina Javerzat, Daniele Notarmuzi
Rigidity Percolation is a crucial framework for describing rigidity transitions in amorphous systems. We present a new, efficient algorithm to study central-force Rigidity Percolation in two dimensions. This algorithm combines the Pebble Game algorithm, the Newman-Ziff approach to Connectivity Percolation, as well as novel rigorous results in rigidity theory, to exactly identify rigid clusters over the full bond concentration range, in a time that scales as $ N^{1.02}$ for a system of $ N$ nodes. Besides opening the way to accurate numerical studies of Rigidity Percolation, our work provides new insights on specific cluster merging mechanisms that distinguish it from the standard Connectivity Percolation problem.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Code available at this https URL
Reshaping the anomalous Hall response in tilted 3D system with disorder correction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
The anomalous Hall conductivity in the nodal line semimetals (NLSMs) due to the presence of a symmetry-protected nodal ring adds complexity in the investigation of their transport properties. By employing quantum kinetic theory and considering the weak disorder limit, we analyze the intraband and interband parts of anomalous Hall conductivity in the tilted 3D Dirac NLSMs. Our findings reveal that the net anomalous response is mainly contributed by the interband part. Further, the latter part gives non zero results by breaking inversion symmetry via tilt. We observe that the competition between the tilt and the chemical potential emerges kinks at distinct characteristic frequencies in the intrinsic interband part of the anomalous conductivity. On the other hand, the disorder driven interband component of the conductivity exhibits a prominent peak at low chemical potential, followed by a sign change. Notably, the disorder or extrinsic contribution to the response dominates over the intrinsic interband contribution, making it a crucial factor for the study of the overall response of a three-dimensional system.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Accepted in the New Journal of Physics
The interplay of ferroelectricity and magneto-transport in non-magnetic moiré superlattices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Siqi Jiang, Renjun Du, Jiawei Jiang, Gan Liu, Jiabei Huang, Yu Du, Yaqing Han, Jingkuan Xiao, Di Zhang, Fuzhuo Lian, Wanting Xu, Siqin Wang, Lei Qiao, Kenji Watanabe, Takashi Taniguchi, Xiaoxiang Xi, Wei Ren, Baigeng Wang, Alexander S. Mayorov, Kai Chang, Hongxin Yang, Lei Wang, Geliang Yu
The coupling of ferroelectricity and magnetic order provides rich tunability for engineering material properties and demonstrates great potential for uncovering novel quantum phenomena and multifunctional devices. Here, we report interfacial ferroelectricity in moiré superlattices constructed from graphene and hexagonal boron nitride. We observe ferroelectric polarization in an across-layer moiré superlattice with an intercalated layer, demonstrating a remnant polarization comparable to its non-intercalated counterpart. Remarkably, we reveal a magnetic-field enhancement of ferroelectric polarization that persists up to room temperature, showcasing an unconventional amplification of ferroelectricity in materials lacking magnetic elements. This phenomenon, consistent across devices with varying layer configurations, arises purely from electronic rather than ionic contributions. Furthermore, the ferroelectric polarization in turn modulates quantum transport characteristics, suppressing Shubnikov-de Haas oscillations and altering quantum Hall states in polarized phases. This interplay between ferroelectricity and magneto-transport in non-magnetic materials is crucial for exploring magnetoelectric effects and advancing two-dimensional memory and logic applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Nature Communications, volume 16, Article number: 5640 (2025)
Versatile multi-q antiferromagnetic charge order in correlated vdW metals
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Y. Fujisawa, P. Wu, R. Okuma, B. R. M. Smith, D. Ueta, R. Kobayashi, N. Maekawa, T. Nakamura, C-H. Hsu, Chandan De, N. Tomoda, T. Higashihara, K. Morishita, T. Kato, Z. Y. Wang, Y. Okada
Following the discovery of graphene, interest in van der Waals (vdW) materials has surged; yet, advancing “beyond graphene” physics requires the development of quantum material platforms that host versatile many-body states. Using scanning tunneling microscopy and spectroscopy at 300 mK, we uncover two competing states in vdW metal CeTe3: charge-ordered in-plane antiferromagnetic phases forming stripe and checkerboard patterns. Remarkably, the competition between them is tuned through a modest in-plane magnetic field (approximately 1.5 T), revealing significant cooperative phenomena between frustrated antiferromagnetism, charge order, and competing Fermi surface nesting. Underlying strongly intertwined many-body states are consistently signaled by density of states deformations exceeding plus/minus 30 meV scale across the Fermi level. Our findings provide a promising correlated vdW platform hosting versatile two-dimensional many-body physics, offering a fertile ground to explore topologically nontrivial multi-q charge-ordered antiferromagnetism, quantum criticality, unconventional superconductivity, and their potential interconnections.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
Equilibrium distribution of the liquid phase in an unsaturated granular material
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Lazar Loredana, Clavaud Cécile, Amon Axelle
In an unsaturated granular material, the spatial distribution of the liquid phase results from the competition between gravity and capillary forces. We show that, in the funicular regime, it can be described by a Boltzmann law, with static disorder playing the role of thermal agitation. We propose an approach based on a Langevin equation to derive this distribution, and compare our predictions with conductivity measurements giving the local water content as a function of height in a wet granular medium. We show that experimental data obtained with samples of different polydispersities collapse on a single master curve consistent with our model.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn), Geophysics (physics.geo-ph)
Decomposition of general grain boundaries
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Wei Wan, Junwen Deng, Changxin Tang
As a central part of microstructure evolution, grain boundary (GB) migration is believed to be both monolithic and unidirectional. But here, we introduce the concept of GB decomposition: one GB separates into two new GBs by controlling the Peach-Koehler forces on its disconnections. Molecular dynamics simulation is used to reveal the disconnection mechanisms and direction-dependent motion behaviors associated with the reversible decomposition of a nickel {\Sigma}7 general GB. We also observed a decomposition-like process in a high-energy diffraction microscopy (HEDM) dataset of high purity nickel polycrystal (Science 2021, 374, 189-193), and performed HEDM-data-based simulation to confirm it. The decomposition should be considered as a new GB migration behavior, based on its particularity and potential universality.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
12 pages, 5 figures, 1 tables, 66 references
Robust Ferroelectricity in Silicon Dioxide upon Intercalation of Ammonia
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Yaxin Gao, Menghao Wu, Jun-Ming Liu
The nanoelectronic applications of current ferroelectrics have been greatly impeded by their incompatibility with silicon. In this paper we propose a way to induce ferroelectricity in silicon dioxide (SiO2), which is still the most widely used dielectric material in silicon-based chips. We show first-principles evidence that the intercalation of NH3 molecules into crystalline SiO2 is exothermic, where NH3 molecules form quasi-bonds with SiO2, giving rise to large and robust polarizations. In general, such polarization can be reversed via the reformation of N-Si bondings, which is multiaxial so vertical ferroelectricity may emerge in their thin-films of any facets. When the applied external electric field is large enough, however, the system may exhibit unconventional quantized ferroelectricity of unprecedented magnitude, where NH3 may migrate for multiple lattice constants like mobile ions in ion conductors. Compared with ion conductors with charged mobile ions and ion vacancies that may lead to current leakage, herein the intercalated systems can be denoted as neutral ion conductors where both pristine SiO2 and SiO2 filled with NH3 are insulating. Similar ferroelectricity may exist in various SiO2 crystalline polymorphs, its amorphous phase, and other porous structures intercalated by NH3. Our findings may not only resolve the bottleneck issues for the compatibility of ferroelectrics and silicon, but also develop unconventional mechanisms of ferroelectricity.
Materials Science (cond-mat.mtrl-sci)
Cascade of Modal Interactions in Nanomechanical Resonators with Soft Clamping
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Zichao Li, Minxing Xu, Richard A. Norte, Alejandro M. Aragón, Peter G. Steeneken, Farbod Alijani
Cascades of dynamical phenomena, where energy and motion transfer across coupled degrees of freedom, underlie complex behavior in physical systems spanning multiple time and length scales. Here, we demonstrate that soft-clamping techniques commonly employed to enhance the quality factor of nanomechanical resonators, can also be harnessed to engineer cascaded energy transfer conditions, enabling the sequential excitation of an increasing number of coupled vibrational modes during frequency sweeps. Using Si3N4 nanostrings with soft-clamping supports, we identify the conditions for mode coupling and obtain interactions among five flexural resonances , achieving a quasi-constant amplitude of the targeted resonant response over a broad frequency range. Analytical and nonlinear reduced-order models reveal that soft clamping can not only facilitate a sequence of interactions, but also amplify the geometric nonlinearity of the driven mode, enhancing effective spring hardening by more than an order of magnitude through dispersive couplings. This ability to activate and control energy flow in nanomechanical systems offers a strategy for realizing programmable nonlinear dynamics for next-generation resonators.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Adsorbate-induced formation of a surface-polarity-driven nonperiodic superstructure
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Chi Ming Yim, Yu Zheng, Olivia R. Armitage, Dibyashree Chakraborti, Craig J. Wells, Seunghyun Khim, Andrew P. Mackenzie, Peter Wahl
The chemical and electronic properties of surfaces and interfaces are important for many technologically relevant processes, be it in information processing, where interfacial electronic properties are crucial for device performance, or in catalytic processes, which depend on the types and densities of active nucleation sites for chemical reactions. Quasi-periodic and nonperiodic crystalline surfaces offer new opportunities because of their inherent inhomogeneity, resulting in localisation and properties vastly different from those of surfaces described by conventional Bravais lattices. Here, we demonstrate the formation of a nonperiodic tiling structure on the surface of the frustrated antiferromagnet PdCrO2 due to hydrogen adsorption. The tiling structure exhibits no long-range periodicity but comprises few-atom hexagonally packed domains covering large terraces. Measurement of the local density of states by tunnelling spectroscopy reveals adsorption-driven modifications to the quasi-2D electronic structure of the surface layer, showing exciting opportunities arising from electron localisation.
Materials Science (cond-mat.mtrl-sci)
Communications Materials 6, 128 (2025)
Spontaneous emergence of altermagnetism in the single-orbital extended Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Jin-Wei Dong, Yu-Han Lin, Ruiqing Fu, Xianxin Wu, Gang Su, Ziqiang Wang, Sen Zhou
Altermagnetism (AM), the recently discovered third class of collinear magnetic order, is characterized by non-relativistic momentum-dependent spin-split electronic structure with compensated zero net magnetization. It can arise from the conventional antiferromagnetism by introducing local anisotropy on the two opposite-spin sublattices, either through structural changes in local crystallographic symmetry or spontaneous emergence of local staggered orbital order from electron correlations in multi-orbital systems. Here, we demonstrate on the two-dimensional square lattice that a $ d$ -wave AM can emerge spontaneously in the single-orbital extended Hubbard model, without invoking the spin-orbital coupling and multi-orbital physics. We carry out mean-field studies on the concrete single-orbital $ t$ -$ U$ -$ V$ model with $ U$ and $ V$ the onsite and nearest-neighbor Coulomb interactions, obtaining the ground states, analyzing their properties, and determining the phase diagram in the $ U$ -$ V$ plane. The $ d$ -wave AM with novel spin-transport behavior is found to be stabilized in a wide region of the phase diagram when the system is doped away from half-filling, actualized by the coexistence of onsite antiferromagnetic order and complex $ d$ -wave nearest-neighbor spin bond orders. Our findings provide an alternative route to achieve AM and substantially expand the range of candidate AM materials.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 3 figures
Quantum state transfer and maximal entanglement between distant qubits using a minimal quasicrystal pump
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Arnob Kumar Ghosh, Rubén Seoane Souto, Vahid Azimi-Mousolou, Annica M. Black-Schaffer, Patric Holmvall
Coherent quantum state transfer over macroscopic distances between non-neighboring elements in quantum circuits is a crucial component to increase connectivity and simplify quantum information processing. To facilitate such transfers, an efficient and easily controllable quantum pump would be highly beneficial. In this work, we demonstrate such a quantum pump based on a one-dimensional quasicrystal Fibonacci chain (FC). In particular, we utilize the unique properties of quasicrystals to pump the edge-localized winding states between the two distant ends of the chain by only minimal manipulation of the FC at its end points. We establish the necessary conditions for successful state transfer within a fully time-dependent picture and also demonstrate robustness of the transfer protocol against disorder. We then couple external qubits to each end of the FC and establish highly adaptable functionality as a quantum bus with both on-demand switching of the qubit states and generation of maximally entangled Bell states between the qubits. Thanks to the minimal control parameters, the setup is well-suited for implementation across diverse experimental platforms, thus establishing quasicrystals as an efficient platform for versatile quantum information processing.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
10+8 pages, 5+10 figures; Comments are welcome
Higher-order bulk photovoltaic effects, quantum geometry and application to $p$-wave magnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
The injection and shift currents are generalized to the $ \ell $ th-order injection and shift currents for the longitudinal conductivities in the two-band model, where $ \ell $ is the power of the applied electric field. In addition, the formulas for the higher-order injection current are expressed in terms of the quantum metric and the higher-order shift current in terms of the higher-order quantum connection. Then, they are applied to $ p$ -wave magnets. It is shown that the injection and shift currents are zero. On the other hand, the $ \ell $ th-order injection and shift currents with odd $ \ell $ are nonzero when the direction of the Néel vector of the $ p$ -wave magnet points to an in-plane direction.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 4 figures
Microscopic evidence for Fulde-Ferrel-Larkin-Ovchinnikov state and multiband effects in KFe$_2$As$_2$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-02 20:00 EDT
X. Y. Liu, Z. Kao, J. Luo, J. Yang, A. F. Fang, J. Zhao, R. Zhou, Guo-qing Zheng
The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state is a superconducting phase characterized by broken translational-symmetry, where Cooper pairs form with non-zero momentum between Zeeman-split Fermi surfaces. This state is highly sensitive to band structure and pairing symmetry. In multiband superconductors, the FFLO state can significantly deviate from its standard form, but experimental verification has remained challenging. Here, we present $ ^{75}$ As nuclear magnetic resonance (NMR) measurements on the multiband superconductor KFe$ _2$ As$ 2$ . In the low-temperature, high-magnetic-field region above the upper critical field $ B{c2}$ , we observe a clear increase in the second moment of the NMR spectrum, along with a strong enhancement in the spin-lattice relaxation rate divided by temperature 1/$ T_1$ T$ . These results indicate an emergence of superconducting spin smecticity and Andreev bound states from the spatially modulation of the superconducting gap, providing microscopic evidence for the FFLO state. The obtained phase diagram reveals a distinct boundary line between the FFLO and homogenous superconducting (HSC) states with a low critical temperature of the FFLO state $ T^\ast \approx 0.2 T_c$ , which can be attributed to the multiband effects in KFe$ _2$ As$ _2$ . Our results show that the iron-based superconductors are a good material platform for studying the FFLO state and highlight the importance of the multiband effects on this exotic phase.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 4 figures
Diffusion of acceptor dopants in monoclinic $β$-Ga$_2$O$_3$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Channyung Lee, Michael A. Scarpulla, Elif Ertekin, Joel B. Varley
$ \beta$ -Ga$ 2$ O$ 3$ is a leading ultra-wide band gap semiconductor, but its performance depends on precise control over dopant incorporation and stability. In this work, we use first-principles calculations to systematically assess the diffusion behavior of eight potential deep-level substitutional acceptors (Au, Ca, Co, Cu, Fe, Mg, Mn, and Ni) in $ \beta$ -Ga$ 2$ O$ 3$ . We consider two key diffusion mechanisms: (i) interstitial diffusion under non-equilibrium conditions relevant to ion implantation, and (ii) trap-limited diffusion (TLD) under near-equilibrium thermal annealing conditions. Our results reveal a strong diffusion anisotropy along the b and c axes, with dopant behavior governed by competition between diffusion and incorporation (or dissociation) activation energies. Under interstitial diffusion, Ca$ ^{2+}{\text{i}}$ and Mg$ ^{2+}{\text{i}}$ show the most favorable combination of low migration and incorporation barriers, making them promising candidates for efficient doping along the b and c axes, respectively. In contrast, Au$ ^{+}{\text{i}}$ diffuses readily, but exhibits an incorporation barrier that exceeds 5 eV, rendering it ineffective as a dopant. From a thermal stability perspective, Co$ ^{2+}{\text{i}}$ shows poor activation but high diffusion barriers, which may suppress undesirable migration at elevated temperatures. Under trap-limited diffusion, the dissociation of dopant-host complexes controls mobility. Mg$ ^{2+}{\text{i}}$ again emerges as a leading candidate, exhibiting the lowest dissociation barriers along both axes, whereas Co$ ^{2+}{\text{i}}$ and Fe$ ^{2+}_{\text{i}}$ display the highest barriers, suggesting improved dopant retention under thermal stress. Our findings guide dopant selection by balancing activation and thermal stability, essential for robust semi-insulating substrates.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Quantum Hall Effect and Chern Phases in the 1/5-Depleted Square Lattice
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Sara Aghtouman, Godfrey Gumbs, Mir Vahid Hosseini
We investigate the fractional energy spectrum and quantum Hall response of a two-dimensional 1/5-depleted square lattice subjected to a perpendicular magnetic field. Using a tight-binding model that includes both nearest-neighbor (t_1) and next-nearest-neighbor (t_2) hopping, we compute the Hofstadter butterfly and extract quantized Hall conductivities via Chern number calculations. In the absence of diagonal hopping (t_2 =0), the spectrum exhibits exact particle-hole and flux-inversion symmetries, and the total Chern number across all bands vanishes. When t_2 is introduced, these symmetries are broken, the butterfly becomes deformed, new gaps open, and -remarkably-a nonzero total Chern sum can emerge, signaling unconventional topological phases. By systematically varying t_1 and t_2, we identify regimes with large individual Chern indices and parameter windows where gap stability and Hall plateaus are optimized. Our results demonstrated that lattice depletion combined with diagonal hopping provides a tunable route to engineer robust Chern insulators in both artificial and oxide-based square-lattice systems.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Scaling, Fractal Dynamics and Critical Exponents{: Application} in a non-integer dimensional Ising model
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-02 20:00 EDT
Henrique A. de Lima, Ismael S. S. Carrasco, Marcio Santos, Fernando A. Oliveira
Moving beyond simple associations, researchers need tools to quantify how variables influence each other in space and time. Correlation functions provide a mathematical framework for characterizing these essential dependencies, revealing insights into causality, structure, and hidden patterns within complex systems. In physical systems with many degrees of freedom, such as gases, liquids, and solids, a statistical analysis of these correlations is essential. For a field $ \Psi(\vec{x},t)$ that depends on spatial position $ \vec{x}$ and time $ t$ , it is often necessary to understand the correlation with itself at another position and time $ \Psi(\vec{x}_0,t_0)$ . This specific function is called the autocorrelation function. In this context, the autocorrelation function for order–parameter fluctuations, introduced by Fisher, provides an important mathematical framework for understanding the second-order phase transition at equilibrium. However, his analysis is restricted to a Euclidean space of dimension $ d$ , and an exponent $ \eta$ is introduced to correct the spatial behavior of the correlation function at $ T=T_c$ . In recent work, Lima et al demonstrated that at $ T_c$ a fractal analysis is necessary for a complete description of the correlation function. In this study, we investigate the fundamental physics and mathematics underlying phase transitions. In particular, we show that the application of modern fractional differentials allows us to write down an equation for the correlation function that recovers the correct exponents below the upper critical dimension. We obtain the exact expression for the Fisher exponent $ \eta$ . Furthermore, we examine the Rushbrooke scaling relation, which has been questioned in certain magnetic systems, and, drawing on results from the Ising model, we confirm that both our relations and the Rushbrooke scaling law hold even when $ d$ is not an integer.
Statistical Mechanics (cond-mat.stat-mech)
Development of an Atomic Layer Deposition System for Deposition of Alumina as a Hydrogen Permeation Barrier
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-02 20:00 EDT
Zachary R. Robinson, Jeffrey Woodward, Alexander C. Kozen, Joshua Ruby, Tyler Liao, Luke Herter, Rashad Ahmadov, Mark D. Wittman, Matthew Sharpe
Tritium permeation into and through materials poses a critical challenge for the development of nuclear fusion reactors. Minimizing tritium permeation is essential for the safe and efficient use of available fuel supplies. In this work, we present the design, construction, and validation of custom atomic layer deposition (ALD) and deuterium permeation measurement systems aimed at developing thin-film hydrogen permeation barriers. Using the ALD system, we deposited conformal Al2O3 films on copper foil substrates and characterized their growth behavior, morphology, and composition. ALD growth rates of 1.1 angstrom/cycle were achieved for temperatures between 100 degrees C and 210 degrees C. Permeation measurements on bare and ALD-coated copper foils revealed a significant reduction in deuterium flux with the addition of a 10nm Al2O3 layer. While bare copper followed diffusion-limited transport consistent with Sievert’s law, the ALD-coated samples exhibited surface-limited, pore-mediated transport with linear pressure dependence. Arrhenius analysis showed distinct differences in activation energy for the two transport regimes, and permeation reduction factors (PRFs) exceeding an order of magnitude were observed. These results demonstrate the potential of ALD-grown Al2O3 films as effective hydrogen isotope barriers and provide a foundation for future studies on film optimization and integration into fusion-relevant components.
Materials Science (cond-mat.mtrl-sci)
Suppression of shot noise at a Kondo destruction quantum critical point
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Yiming Wang, Shouvik Sur, Fang Xie, Haoyu Hu, Silke Paschen, Douglas Natelson, Qimiao Si
Strange metal behavior has been observed in an expanding list of quantum materials, with heavy fermion metals serving as a prototype setting. Among the intriguing questions is the nature of charge carriers; there is an increasing recognition that the quasiparticles are lost, as captured by Kondo destruction quantum criticality. Among the recent experimental advances is the measurement of shot noise in a heavy-fermion strange metal. We are thus motivated to study current fluctuations by advancing a minimal Bose-Fermi Kondo lattice model, which admits a well-defined large-$ N$ limit. Showing that the model in equilibrium captures the essential physics of Kondo destruction, we proceed to derive quantum kinetic equations and compute shot noise to the leading nontrivial order in $ 1/N$ . Our results reveal a strong suppression of the shot noise at the Kondo destruction quantum critical point, thereby providing the understanding of the striking experiment. Broader implications of our results are discussed.
Strongly Correlated Electrons (cond-mat.str-el), Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 + 6 pages, 4 figures
Ultrafast electron heating as the dominant driving force of photoinduced terahertz spin currents
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Reza Rouzegar, Pilar Jimenez-Cavero, Oliver Gueckstock, Mohamed Amine Wahada, Quentin Remy, Irene Lucas, Gerhard Jacob, Mathias Kläui, Michel Hehn, Georg Woltersdorf, Tobias Kampfrath, Tom. S. Seifert
Ultrafast spintronics strongly relies on the generation, transport, manipulation and detection of terahertz spin currents (TSCs). In F|HM stacks consisting of a ferromagnetic layer F and a heavy-metal layer HM, ultrafast spin currents are typically triggered by femtosecond optical laser pulses. A key open question is whether the initial step, optical excitation and injection of spin currents, can be controlled by tuning the photon energy of the femtosecond pulse. While many theoretical works suggest a marked impact of photon-energy and of highly excited non-thermal electrons, profound experimental evidence is lacking. Here, we use terahertz-emission spectroscopy to study TSCs triggered with two different photon energies of 1.5 eV and 3 eV. We study a wide range of magnetic systems covering metallic ferromagnets, ferrimagnetic insulators, half-metals, as well as systems including tunneling barriers, and rare-earth metallic alloys. We find that variation of the exciting photon energy does not change the dynamics and only slightly the amplitude of the induced TSC in all sample systems. Our results reveal that the ultrafast pump-induced heating of electrons is a highly efficient process for generating TSCs, whereas highly excited primary photoelectrons are of minor importance.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 4 figures
Orbital Hall Effect and Angular Momentum Dynamics in Confined Geometries
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-02 20:00 EDT
Egor I. Kiselev, Benoît Douçot, Roderich Moessner
We present an analysis of the orbital Hall effect (OHE) in a strip geometry and derive a formula for the orbital angular momentum (OAM) accumulation at the edges. The result is expressed in terms of band structure parameters and scattering rates, providing a link between experimental observations of the OHE and the underlying microscopics. A key result is that the effective OAM decay rate follows a Dykonov-Perel-like scaling and is inversely proportional to the electron scattering rate, even if the latter is small. Furthermore, investigating OAM transport in an inhomogeneous setting, we show that non-Ohmic flows and spatially varying electric fields result in contributions to the OHE which are distinct from the well known intrinsic and extrinsic mechanisms.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Quantum Carpets of Higgs particles in a Supersolid
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-02 20:00 EDT
Koushik Mukherjee, Malte Schubert, Ralf Klemt, Thomas Bland, Tilman Pfau, Stephanie Reimann
Supersolids formed from dipolar Bose-Einstein condensates (BECs) exhibit spontaneous density modulation while maintaining global phase coherence. This state of matter supports gapped amplitude (Higgs) excitations featuring a quadratic dispersion relation. While Higgs modes are typically strongly damped due to coupling with other amplitude and phase modes, imposing an experimentally realistic toroidal geometry allows us to numerically study the time evolution and dispersion of a localized Higgs quasiparticle excitation, with minimal residual coupling to sound modes. Strikingly, the quadratic dispersion leads to the occurrence of (fractional) revivals, similar to those seen in the optical Talbot effect or the so-called quantum carpets. The revival times provide a novel method for determining the effective mass of the Higgs particle through a non-spectroscopic approach. These results pave the way for further studies of coherent Higgs dynamics and mutual interactions between Higgs particles.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
11 pages, 7 figures
Charge pumps, pivot Hamiltonians and symmetry-protected topological phases
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-02 20:00 EDT
Nick. G. Jones, Ryan Thorngren, Ruben Verresen, Abhishodh Prakash
Generalised charge pumps are topological obstructions to trivialising loops in the space of symmetric gapped Hamiltonians. We show that given mild conditions on such pumps, the associated loop has high-symmetry points which must be in distinct symmetry-protected topological (SPT) phases. To further elucidate the connection between pumps and SPTs, we focus on closed paths, pivot loops', defined by two Hamiltonians, where the first is unitarily evolved by the second pivot’ Hamiltonian. While such pivot loops have been studied as entanglers for SPTs, here we explore their connection to pumps. We construct families of pivot loops which pump charge for various symmetry groups, often leading to SPT phases – including dipole SPTs. Intriguingly, we find examples where non-trivial pumps do not lead to genuine SPTs but still entangle representation-SPTs (RSPTs). We use the anomaly associated to the non-trivial pump to explain the a priori `unnecessary’ criticality between these RSPTs. We also find that particularly nice pivot families form circles in Hamiltonian space, which we show is equivalent to the Hamiltonians satisfying the Dolan-Grady relation – known from the study of integrable models. This additional structure allows us to derive more powerful constraints on the phase diagram. Natural examples of such circular loops arise from pivoting with the Onsager-integrable chiral clock models, containing the aforementioned RSPT example. In fact, we show that these Onsager pivots underlie general group cohomology-based pumps in one spatial dimension. Finally, we recast the above in the language of equivariant families of Hamiltonians and relate the invariants of the pump to the candidate SPTs. We also highlight how certain SPTs arise in cases where the equivariant family is labelled by spaces that are not manifolds.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
Beyond von Mises Truss Models: Emergent Bistability in Mechanical Metamaterials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-02 20:00 EDT
Md Nahid Hasan, Taylor E. Greenwood, Sharat Paul, Bolei Deng, Qihan Liu, Yong Lin Kong, Pai Wang
We observe and analyze the phenomenon of bistability emergent from cooperative stiffening in hyper-elastic metamaterials. Using experimental and numerical results of identical geometric designs, we show evidence that a single unit is unistable while combining two units can result in bistability. Our study demonstrates that the von Mises truss model cannot describe such emergent behavior. Hence, we construct a novel and simple analytical model to explain this phenomenon.
Soft Condensed Matter (cond-mat.soft)
Microsecond-scale high-survival and number-resolved detection of ytterbium atom arrays
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-02 20:00 EDT
Alessandro Muzi Falconi, Riccardo Panza, Sara Sbernardori, Riccardo Forti, Ralf Klemt, Omar Abdel Karim, Matteo Marinelli, Francesco Scazza
Scalable atom-based quantum platforms for simulation, computing, and metrology require fast high-fidelity, low-loss imaging of individual atoms. Standard fluorescence detection methods rely on continuous cooling, limiting the detection range to one atom and imposing long imaging times that constrain the experimental cycle and mid-circuit conditional operations. Here, we demonstrate fast and low-loss single-atom imaging in optical tweezers without active cooling, enabled by the favorable properties of ytterbium. Collecting fluorescence over microsecond timescales, we reach single-atom discrimination fidelities above 99.9% and single-shot survival probabilities above 99.5%. Through interleaved recooling pulses, as short as a few hundred microseconds for atoms in magic traps, we perform tens of consecutive detections with constant atom-retention probability per image - an essential step toward fast atom re-use in tweezer-based processors and clocks. Our scheme does not induce parity projection in multiply-occupied traps, enabling number-resolved single-shot detection of several atoms per site. This allows us to study the near-deterministic preparation of single atoms in tweezers driven by blue-detuned light-assisted collisions. Moreover, the near-diffraction-limited spatial resolution of our low-loss imaging enables number-resolved microscopy in dense arrays, opening the way to direct site-occupancy readout in optical lattices for density fluctuation and correlation measurements in quantum simulators.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
8+10 pages, 4+6 figures