CMP Journal 2026-09-10
Statistics
Nature Physics: 1
Science: 18
Physical Review Letters: 30
Physical Review X: 1
arXiv: 87
Research Square: 1
Nature Physics
Trion Hall effect in electron-hole double layers
Original Paper | Bose-Einstein condensates | 2026-09-09 20:00 EDT
Raghav Chaturvedi, Phuong X. Nguyen, Patrick Knüppel, Kenji Watanabe, Takashi Taniguchi, Kin Fai Mak, Jie Shan
The realization of Coulomb-coupled electron-hole double layers has enabled the exploration of equilibrium excitons–bound electron-hole pairs–without a magnetic field. Doping an exciton fluid with additional electrons or holes further creates an equilibrium fluid of trions–bound states of two electrons and one hole and vice versa. Therefore, a trion Hall effect under a magnetic field is expected but has not been demonstrated. Here we report the observation of the trion Hall effect in MoSe2/WSe2 heterostructures, which support Coulomb-coupled layers of electrons and holes with continuously tunable densities. The effect arises from the Lorentz force on trions subjected to a perpendicular magnetic field. By combining magnetotransport and Coulomb drag measurements, we find that an electron-like Hall effect emerges on the hole layer in the presence of negatively charged trions because of Coulomb drag. Furthermore, the effect disappears when trions dissociate at elevated temperatures or high doping densities. These results suggest that transition metal dichalcogenide heterostructures are a candidate for realizing trion-based quantum Hall phenomena.
Bose-Einstein condensates, Quantum fluids and solids, Two-dimensional materials
Science
Open framework-based Brønsted acid-Lewis base interfaces boost proton transfer in the fuel cells
Research Article | Fuel cells | 2026-09-10 03:00 EDT
Qianli Ma马千里), Jiarui Yang杨嘉睿), Jie Li李婕), Zihan Zhao赵子涵), Feiyu Yue岳飞宇), Jianwei Yang杨建伟), Shuang Zhao赵爽), Wenhan Sheng盛文涵), Tang Wang王堂), Shangnan Zhao周尚楠), Junwen Zhou周俊文), Wenli Xu许文莉), Yanli Lu陆艳丽), Ke Wu吴珂), Xianghao Han韩向豪), Xilin Jia贾茜霖), Wenxiu Yang杨文秀), Qianyou Wang王乾有), Yujing Li李煜璟), Zipeng Zhao赵紫鹏), Yu Han韩宇), Shucheng Sun孙树成), Teng Zhang张腾), Xiao Feng冯霄), Bo Wang王博)
Limited proton conductivity within the catalyst layer induces severe ohmic polarizations and constrains power output at high hydrogen-to-electricity efficiencies in proton exchange membrane fuel cells. We demonstrate that proton transfer can be boosted by constructing Brønsted acid-Lewis base interfaces through integrating organic open frameworks with Nafion. These confined interfaces mediate low-barrier relay pathways, disrupt hydrogen bonding to expedite water network reorganization, facilitate consecutive proton transfer, and enrich protons locally. Compared with Nafion, the complexes exhibit an order-of-magnitude increase in proton self-diffusion coefficient, a 6.5-fold rise in proton conductivity, and a 55% reduction in activation energy. When integrated with commercial platinum on carbon, they deliver a fourfold increase in rated power output relative to the baseline, outperforming representative state-of-the-art membrane electrode assemblies with advanced catalysts under similar conditions.
Unphosphorylated tyrosines mediate PD-1 inhibition of T cell signaling condensate formation
Research Article | Signal transduction | 2026-09-10 03:00 EDT
Monica Sharma, Zachary B. Katz, David C. Dewitt, Kiersten M. Ruff, Akashdip Singh, Huan Lan, Wilson Phung, Jeffery Tom, Aimin Song, Jawahar Sudhamsu, John Davies, John G. Quinn, Rohit V. Pappu, Andrey S. Shaw
T cell receptor (TCR) engagement stimulates formation of a biomolecular condensate, including the scaffold protein linker of activated T cells (LAT). We investigated whether the immune-inhibitory receptor programmed cell death protein 1 (PD-1) inhibits by impeding TCR-induced LAT condensation. In vitro reconstitutions revealed that the cytoplasmic domain of PD-1 directly inhibited LAT condensation. This inhibitory interaction required tyrosine residues in the two inhibitory motifs of PD-1. Contrary to current working models, tyrosine phosphorylation eliminated PD-1 inhibition. Replacing tyrosine with tryptophan reconstituted PD-1 inhibition in T cells, confirming that phosphorylation does not mediate this effect. These findings support the concept that hydrogen bond-donating aromatic residues within inhibitory motifs provide the primary mechanism that explains how inhibitory receptors disrupt signaling networks and block immune activation.
The parent bodies of Ryugu and Ivuna formed before those of other carbonaceous chondrites
Research Article | Cosmochemistry | 2026-09-10 03:00 EDT
Noriyuki Kawasaki, Kazuhide Nagashima, Naoya Sakamoto, Wataru Fujiya, Sota Arakawa, Ken-ichi Bajo, Noriko T. Kita, Kouki Kitajima, Alexander N. Krot, Gary R. Huss, Yoshinari Abe, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Martin Bizzarro, Audrey Bouvier, Richard W. Carlson, Marc Chaussidon, Byeon-Gak Choi, Nicolas Dauphas, Andrew M. Davis, Tommaso Di Rocco, Ryota Fukai, Ikshu Gautam, Makiko K. Haba, Yuki Hibiya, Hiroshi Hidaka, Hisashi Homma, Tsuyoshi Iizuka, Trevor R. Ireland, Akira Ishikawa, Shoichi Itoh, Thorsten Kleine, Shintaro Komatani, Ming-Chang Liu, Yuki Masuda, Kazuko Motomura, Frédéric Moynier, Izumi Nakai, Ann Nguyen, Larry Nittler, Andreas Pack, Changkun Park, Laurette Piani, Liping Qin, Sara S. Russell, Maria Schönbächler, Kentaro Terada, Yasuko Terada, Tomohiro Usui, Sohei Wada, Meenakshi Wadhwa, Richard J. Walker, Katsuyuki Yamashita, Qing-Zhu Yin, Tetsuya Yokoyama, Shigekazu Yoneda, Edward D. Young, Hiroharu Yui, Ai-Cheng Zhang, Tomoki Nakamura, Hiroshi Naraoka, Takaaki Noguchi, Ryuji Okazaki, Kanako Sakamoto, Hikaru Yabuta, Masanao Abe, Akiko Miyazaki, Aiko Nakato, Masahiro Nishimura, Tatsuaki Okada, Toru Yada, Kasumi Yogata, Satoru Nakazawa, Takanao Saiki, Satoshi Tanaka, Fuyuto Terui, Yuichi Tsuda, Sei-ichiro Watanabe, Makoto Yoshikawa, Shogo Tachibana, Hisayoshi Yurimoto
Most carbonaceous chondrite (CC) meteorites contain abundant chondrules, millimeter-scale spherical inclusions of previously molten material. Ivuna-type carbonaceous chondrites (CIs) do not contain chondrules, nor do samples of the carbonaceous asteroid Ryugu. CIs and Ryugu share isotopic properties distinct from those of other CCs, implying that their parent bodies formed at a different time or place than those of other CCs. We applied manganese-chromium dating and oxygen isotope thermometry to Ryugu and Ivuna samples. The results indicate that the parent bodies of Ryugu and Ivuna formed less than 2 million years after the beginning of Solar System formation–before the majority of chondrules in CCs and the parent bodies of other CCs formed. This implies that Ryugu and CIs are remnants of an earlier generation of carbonaceous planetesimals.
Extensive and differential platinum chemotherapy mutagenesis in livers of children
Research Article | Cancer genomics | 2026-09-10 03:00 EDT
Anna Wenger, Jean-Baptiste Vannier, Henry Lee-Six, Robin Loesch, Giulia Emanuelli, Manas Dave, Mehdi Layeghifard, Andrew R. J. Lawson, Federico Abascal, Pantelis A. Nicola, Taryn D. Treger, Toochi Ogbonnah, Conor Parks, Thomas R. W. Oliver, Jonathan Kennedy, Angus Hodder, Nathaniel D. Anderson, Felipe Luz Torres Silva, Mi K. Trinh, Thomas Dowe, Marwo Habarwaa, James J. Sun, Sergio Assia-Zamora, Miriam Cortes-Cerisuelo, Wayel Jassem, Charlotte Town, Anil Dhawan, Vandana Jain, Karin Straathof, Maesha Deheragoda, Iñigo Martincorena, Liina Palm, J. Ciaran Hutchinson, Tim H. H. Coorens, Claire Trayers, Mariia Yuneva, Nigel Heaton, Adam Shlien, Yoh Zen, Foad J. Rouhani, Sam Behjati
Childhood cancer survivors often experience late adverse effects that may be linked to chemotherapy mutagenesis. We studied chemotherapy mutagenesis in normal pediatric tissues using duplex sequencing (NanoSeq) to enable the detection of mutations from single DNA molecules. We found that platinum chemotherapeutics increased the mutation burdens of normal pediatric tissues to levels seen in adults. In the liver, platinum agents imparted a tissue-specific mutational signature that was absent from other tissues. Gene-focused duplex sequencing revealed that chemotherapy mutagenesis generates a great diversity of nonsynonymous variants, some of which may have functional potential, such as leukemogenic variants in blood. Our findings demonstrate extensive chemotherapy mutagenesis in normal tissues of children, which may provide a plausible link between chemotherapy exposure and adverse effects in later life.
Discovery of an intrinsic non-Hermitian phase transition in a bulk condensed-matter system
Research Article | Many-body dynamics | 2026-09-10 03:00 EDT
Jingwen Li, Michael Turaev, Masakazu Matsubara, Kristin Kliemt, Cornelius Krellner, Shovon Pal, Manfred Fiebig, Johann Kroha
Across regular phase transitions, systems remain in thermal equilibrium. However, when a system is driven far from equilibrium, non-Hermitian phase transitions may arise where the dynamical behavior–rather than steady properties–undergoes a qualitative change at a critical, so-called exceptional point. We experimentally realize a non-Hermitian phase transition in a bulk condensed-matter system. Optical excitation creates charge carriers in ferromagnetic europium monoxide. In a temperature-dependent interplay with the Hermitian transition to ferromagnetic order, a non-Hermitian change of the relaxation dynamics occurs, manifesting in our time-resolved reflection data as the transition from biexponential real to single-exponential complex decay. Our theory models this behavior and suggests that non-Hermitian phase transitions may generically emerge in bulk condensed matter.
The complete telomere-to-telomere sequence of a mouse Y chromosome
Research Article | Genomics | 2026-09-10 03:00 EDT
Qilin Li, Junli Liu, Si Chen, Yixuan Hu, Dengfeng Li, Zhuojie Su, Yanxiao Zhang, Xiaochun Yu
The mouse Y chromosome is essential for male reproduction, yet the GRCm39 reference contains 25 gaps, particularly in repetitive and complex regions. Here, we assembled a telomere-to-telomere Y chromosome (mT2T Y) of 95.21 Mb from a C57BL/6 mouse incorporating parental genomes. This assembly fills all gaps, corrects structural errors, and adds over 8.70 Mb of previously unassembled sequence to the reference genome. We annotated 142 previously unidentified genes, identified Y specific satellite arrays, and mapped homologous recombination loci in the pseudoautosomal region (PAR). Analysis of X Y homologous gene expression revealed a Y chromosome dosage compensation mechanism. By combining mT2T Y with T2T mhaESC, we completed the T2T assembly of all C57BL/6 chromosomes, designated T2T mhaESC+Y, providing a complete C57BL/6 reference genome.
Lean adipocyte oxylipin signaling restrains breast cancer through ferroptosis
Research Article | Cancer metabolism | 2026-09-10 03:00 EDT
Meghan C. Curtin, Abigail E. Jackson, Mark D. Lee, Elisabeth A. Brown, J. Alan Maschek, David H. Lum, James E. Cox, Alana L. Welm, Keren I. Hilgendorf
Obesity increases breast cancer risk and tumor aggressiveness, yet the mechanisms underlying this association remain unclear. In this work, we identify a tumor-suppressive lipid signaling pathway in which mammary adipocytes secrete the oxylipin 9S-hydroxyoctadecadienoic acid (9S-HODE). 9S-HODE induces ferroptosis in breast cancer cells by disrupting iron homeostasis. Adipocytes in obese mammary tissue produce less 9S-HODE, and tumors in obese mice exhibit reduced ferroptosis. Accordingly, ferroptosis inhibition accelerates tumor growth in lean mice, and restoring 9S-HODE suppresses tumor growth in obese mice. In humans, mammary 9S-HODE content is inversely correlated with body mass index, and 9S-HODE inhibits patient-derived breast cancer organoid growth. These findings identify the loss of adipocyte-derived 9S-HODE as a mechanism by which obesity promotes breast cancer and suggest that the restoration of ferroptosis-inducing lipid signaling may be a therapeutic strategy.
Hydroclimatic-driven pulse enrichment amplifies riverine microplastic export in developing countries
Research Article | Microplastics | 2026-09-10 03:00 EDT
Hehao Qin, Maodian Liu, Yanxu Zhang, Qianru Zhang, Changhao Xiao, Chengzhen Zhou, Xingrui Cai, Xinran Qiu, Xuejun Wang
Rivers are key conduits in the global microplastic cycle, but how much they export to ` ocean and what controls this export remain unresolved. Here, we present a global daily dataset of riverine microplastic concentrations and exports and find that rivers delivered far more microplastics to the ocean than most previous estimates suggest. Ninety-six percent of this export originated in the Global South, with Southeast and East Asia contributing >50% of the total flux. Furthermore, ~70% of global freshwater discharge exhibits “pulse enrichment,” whereby rainfall-driven high flows trigger spikes in microplastic concentrations and fluxes; 80% of these cases occur in developing countries. Without stronger upstream controls on plastic production and waste management, climate-driven increases in extreme rainfall may intensify these pulses, worsening marine microplastic pollution.
Chronic type II interferon promotes tumor growth through mitochondrial RNA-induced type I interferon and prostaglandin synthesis
Research Article | Cancer immunology | 2026-09-10 03:00 EDT
Melissa A. Johnson, Siva Karthik Varanasi, Kailash Chandra Mangalhara, Kathryn Lande, Gladys R. Rojas, Pau B. Esparza-Moltó, Mack B. Reynolds, Neva Olliffe, Karl Wessendorf-Rodriguez, Sagnika Ghosh, Dan Chen, Alexandra G. Moyzis, Matthew P. Donnelly, Rebecca Chinn, Ziyan Xu, Kym J. Grae, Victoria Tripple, Michael A. LaPorta, Christian M. Metallo, Diana C. Hargreaves, Susan M. Kaech, Gerald S. Shadel
Interferons (IFNs) are proinflammatory cytokines that promote immune cell engagement to eliminate malignant cells. Paradoxically, chronic interferon signaling can also activate anti-inflammatory mechanisms that allow cancer cells to evade the immune system. In this study, we sought to determine the cellular mechanisms underlying this switch from antitumorigenic to protumorigenic interferon activity. We show that chronic type II interferon (IFN-II) exposure distinctively induced tumor growth by activating a type I interferon (IFN-I) response mediated by release of double-stranded mitochondrial RNA (ds-mtRNA) into the cytoplasm. This IFN-I signal synergized with IFN-II to enhance tumor growth by increasing immunosuppressive prostaglandin E2 (PGE2) synthesis through increased cyclooxygenase 2 expression. Elimination of PGE2 synthesis in immunotherapy-resistant melanoma cells restored their responsiveness to anti-PD1 treatment, indicating that this covert mtRNA-IFN-prostaglandin pathway could be a therapeutic target to combat immunotherapy resistance.
Glycan recognition by a plant damage-sensing immune receptor
Research Article | 2026-09-10 03:00 EDT
Pedro Jiménez-Sandoval, Owen Kentish, Caroline Broyart, Hyun Kyung Lee, Klara Culjak, Uwe Osswald, Meriem Aitouguinane, Emanuele Tettamanti, Manon Schmidli, Lu Zhang, Louis-Philippe Maier, Charles Roussin-Léveillée, Diego José Berlanga, Marina Martin-Dacal, Miguel Angel Torres, Varun Kumar, Patricia Fernández-Calvo, José M. Jimenez-Gomez, Philippe Reymond, Alberto P. Macho, Fabian Pfrengle, Lucía Jordá, Antonio Molina, Julia Santiago
Pathogens target and degrade the extracellular matrix surrounding plant cells. A central question is how cell wall-derived damage-associated molecular patterns (DAMPs) are recognized and integrated to trigger immune responses. We address this question by determining the structure of the extracellular multidomain of the IGP1 receptor in both apo form and bound to the cellulose-derived DAMP cellotriose. Structural analyses reveal that constitutive interactions of Leucine Rich Repeat (LRR)-malectin domains preconfigure IGP1 for ligand recognition and that the receptor features a highly specific sugar-binding pocket in the LRR domain capable of distinguishing fine variations in glycan structures. By directly sensing cello-oligomers, IGP1 operates as a cell wall surveillance receptor that links pathogen-induced wall degradation to immune alerting, equipping plants to mount rapid and robust defense responses.
Endurance beyond 10 billion cycles in wurtzite ferroelectrics by confining nitrogen vacancies
Research Article | Ferroelectrics | 2026-09-10 03:00 EDT
Ruiqing Wang, Feng Zhu, Haoji Qian, Jiuren Zhou, Wenxin Sun, Siying Zheng, Jiajia Chen, Bochang Li, Yan Liu, Peng Zhou, Yue Hao, Genquan Han
Wurtzite ferroelectrics could provide a route to wafer-scale integrated ferroelectric memories but are limited by endurance, typically failing at ~108 cycles. We identified nitrogen-vacancy (VN) clustering and long-range percolative migration as the defect-mediated pathways that drive leakage-current growth and dielectric breakdown. We combined a spatially engineered aluminum scandium nitride/aluminum nitride (AlScN/AlN) superlattice with a dynamic recovery protocol to spatially and energetically confine VN evolution that stabilized defect topology under cyclic electrical stress and suppressed hard breakdown and ferroelectric degradation. We demonstrated endurance beyond 1010 cycles in wurtzite ferroelectrics under a complete-switching criterion (remnant polarization ≥ 100 microcoulombs per square centimeter). These findings establish VN confinement as a scalable defect-topology framework that couples atomic-scale defect stability to reliable ultradense ferroelectric memories and provide guidance for next-generation nonvolatile memory technologies.
Growth rate overrides the benefit of extended growing season from boreal to semiarid conifers
Research Article | Tree physiology | 2026-09-10 03:00 EDT
Antoine Cabon, Patrick Fonti, Georg von Arx, Franco Biondi, J. Julio Camarero, Filipe Campelo, Marco Carrer, Katarina Čufar, Henri Cuny, Annie Deslauriers, Marek Fajstavr, Marina Fonti, David Frank, Alessio Giovannelli, Andreas Gruber, Jožica Gričar, Vladimír Gryc, Aylin Güney, Minhui He, Petr Horáček, Jianguo Huang, Malcolm Hughes, Yuan Jiang, Hans-Peter Kahle, Gregory King, Alexander V. Kirdyanov, Elena Larysch, Xiaoxia Li, Eryuan Liang, Martín de Luis, Harri Mäkinen, Edurne Martínez del Castillo, Sergei Mikhailov, Tobias Walter Miller, Kiyomi Morino, Cristina Nabais, Walter Oberhuber, Momchil Panayotov, Richard L. Peters, Peter Prislan, Sergio Rossi, Seyedehmasoumeh Saderi, Antonio Saracino, Luigi Saulino, Roberto Silvestro, Thomas Seifert, Anne Sophie Sergent, Dominik Florian Stangler, Marko Stojanović, Vaclav Treml, Hanuš Vavrčík, Joana Vieira, Wenjin Wang, Gerhard Wieser, Bao Yang, Yiping Zhang, Emanuele Ziaco, Cyrille B. K. Rathgeber
Climate warming lengthens the productive season in extratropical forests. Yet there is inconclusive evidence on whether this in turn elicits enhanced tree growth and forest carbon sequestration. In this study, we used cellular observations of conifer wood formation spanning boreal to semiarid forests to quantify the relative importance of cambial growth rate versus season length in driving annual cell production, the key process underlying woody growth. We found that rate is the primary driver of annual cell production. Furthermore, whereas the growing season lengthens with annual temperature, growth rate exhibited an optimum at ~6°C, beyond which increasingly dry conditions compromise wood production gains. The negative impact of warming on intra-annual growth dynamics can thus largely offset the benefit of longer growing season on future forest carbon storage.
Paleogenomics and habitat modeling reveal temperate Eurasian origins of woolly rhinoceroses
Research Article | Ancient dna | 2026-09-10 03:00 EDT
Xiao-Le Lei雷晓乐, Jiaoyang Ruan阮骄杨, Xueyuan Liang梁雪原, Raquel Teixeira, Jiangyue Zhang张江月, Alexandre Gilardet, Xu Zhou周旭, Yu Han张江月, Zhihan Zhao赵致晗, Hai-Yan Yue岳海岩, Maxim Kozlikin, Sergey Vasiliev, Stanislav Medvedev, Sergei Kruskop, Song Xing邢松, Ting Wang王婷, Vera Basova, Lijuan Ma马丽娟, Bohua Shi史博华, Qingfeng Shao邵庆丰, Katerina Douka, Michael Shunkov, Alexandra Buzhilova, Love Dalén, He Yu韩雨
The woolly rhinoceros was a prominent Ice Age megafaunal species, and there is limited knowledge regarding its origin and responses to past glacial cycles. We sequenced 29 mitochondrial and 14 nuclear genomes from Pleistocene specimens across Eurasia and modeled the species’ habitats over the past 500,000 years. Our results suggest that its maternal genetic diversity mainly evolved in temperate Eurasia around 460 thousand to 420 thousand years ago during a prolonged glacial-interglacial transition. We found that a ~170-thousand-year-old East Asian individual was ancestral to all later populations, indicating East Asia as one possible origin of Late Pleistocene ancestry. We also identified the Altai region as a major climatic refugium. These findings highlight the crucial role of temperate Eurasia in the evolution of woolly rhinoceroses and the diversification of cold-adapted megafauna.
Mechanism of membrane perforation in rotavirus cell entry
Research Article | Viral entry | 2026-09-10 03:00 EDT
Marilina de Sautu, Conny Leistner, Tomas Kirchhausen, Simon Jenni, Stephen C. Harrison
Cell entry of nonenveloped animal viruses requires translocation of a macromolecular assembly across a cellular membrane. Double-stranded RNA viruses introduce into the target cell an inner capsid particle that does not uncoat further. Instead, it extrudes capped viral mRNA by virtue of polymerase and capping activities within it. As described here, we used cryogenic electron tomography to visualize the full course of rhesus rotavirus entry, from cell attachment and virion uptake to release of the subviral particle. The cryo-tomograms and subtomogram averaging of classified subparticles link high-resolution structures of the virion and its components with time series from live-cell fluorescence microscopy. We outline the mechanism of each step in the entry process, including the membrane perforation step that transfers a subviral particle into the cytosol.
Manipulation of protein translation and stem cell self-renewal by CRISPR activation of rRNA transcription
Research Article | Cell biology | 2026-09-10 03:00 EDT
Maximilian Wiesbeck, Emilie L. Alard, Florencia Merino, Niti Chowdhury, Luisa Egert, Anna Danese, Simon Imhof, Matilde Iraci Borgia, Akshaya Rajan, Nadine Fernandez-Novel Marx, Edina Kepesidis, Anna Köferle, Luis Miguel Cerron-Alvan, Franziska Vierl, Thi-Tram Truong, Manja Thorwirth, Lorina Bilalli, André Santos Dias Mourão, Jovica Ninkovic, Rico Schieweck, Markus Diefenbacher, Stefanie M. Hauck, Paul A. Trainor, Faraz K. Mardakheh, Magdalena Götz, Stefan H. Stricker
Ribosomal RNA (rRNA) transcription rates vary during development, and their dysregulation is linked to diseases such as cancer and ribosomopathies. Owing to their high abundance and genomic redundancy, the functional significance of rRNA levels remains unclear. We developed TAPIR (Targeted Activation of Protein Translation), a CRISPR-based approach to elevate rRNA levels by inducing 47S ribosomal DNA transcription. TAPIR increased nucleolar size and enhanced protein synthesis, even in rapidly proliferating cells. In neural stem cells, elevated translation promoted self-renewal and proliferation in vitro and in vivo. Furthermore, TAPIR enabled the modeling and partial rescue of associated disease phenotypes. Our findings reveal that rRNA levels directly regulate translational output and that protein synthesis capacity can act as a key determinant of mammalian stem cell behavior.
Giant tunneling electroresistance in sliding ferroelectrics
Research Article | Ferroelectrics | 2026-09-10 03:00 EDT
Yue Wang, Yu Zhao, Yifei Zhang, Liutianyi Zhang, Zijian Zhong, Sishuo Liu, Chentao Hou, Fanxin Liu, Bin-Bin Zhang, Zhongming Wei, Yue-Yang Liu, Han Wang, Ping-Heng Tan, Jiangbin Wu
Nonvolatile memories should store information reliably while consuming little energy. Ferroelectric tunnel junctions offer compact readout, but conventional ionic displacement ferroelectrics can fatigue, and two-dimensional sliding ferroelectrics are robust but generate weak readout in two terminal devices. We engineered a van der Waals junction using rhombohedral molybdenum disulfide, hexagonal boron nitride, monolayer graphene, and chromium. This architecture converts small sliding polarization into synergistic modulation of tunneling barrier height and carrier concentration. The devices showed tunneling electroresistance above 10 million, a high conductance state current density of 222 amperes per square centimeter at 0.5 volts, and an endurance beyond 100 billion cycles while switching with 13-nanosecond pulses at an estimated energy of 6.5 femtojoules, offering a route to compact low-power memory.
In situ structure of the human ciliary transition zone links linker defects to primary ciliary dyskinesia
Research Article | 2026-09-10 03:00 EDT
Haixia Zhou, Lea Terbeck, Andrew Berical, Marine Brunet, Sven M. Lange, Jacob R. Anderson, Heike Olbrich, Diana Carolin Bracht, Kai Wohlgemuth, Cynthia Rieck, Johanna Raidt, Jürgen Klingauf, Sivagurunathan Sutharsan, Huda Mussaffi, Dario Prais, Victoria Dunphy, Sachiko T. Homma, Paul Guichard, Virginie Hamel, Finn J. Hawkins, Heymut Omran, Alan Brown
The ciliary transition zone (TZ) regulates ciliary proteome composition, yet its molecular architecture, protein content, and contribution to motile ciliopathies remain poorly defined. We applied in situ cryo-electron tomography and subtomogram averaging to human multiciliated epithelial cells. This approach resolved TZ-specific doublet microtubules at subnanometer resolution and identified nine constituent proteins. We identified that ECT2L and DZANK1 form the major linker complexes between adjacent TZ doublet microtubules. Biallelic loss-of-function variants in either gene cause primary ciliary dyskinesia. ECT2L and DZANK1 deficiency disrupted TZ architecture, caused microtubular abnormalities and abnormal bulbous ciliary tips, and impaired mucociliary clearance. These findings establish a direct genetic link between TZ defects and human motile ciliopathy, and illustrate how in situ structural biology can uncover mechanisms of human disease.
Noncoding transcription controls the developmental dynamics of long-range gene regulation
Research Article | 2026-09-10 03:00 EDT
Philippe J. Batut, Michael S. Levine
The genomic regions regulating gene expression are often themselves transcribed into a variety of noncoding RNAs (ncRNAs). However, the regulatory roles of this noncoding transcription remain largely unknown. By using live imaging, we reveal that the sequential transcription of ncRNAs emanating from distinct regulatory elements underlies gene activation in Drosophila embryos. Single-allele co-visualization uncovers that optimal gene activation is achieved by only moderate levels of enhancer activity. Disrupting enhancer-associated ncRNAs causes precocious gene activation, providing evidence that ncRNAs control the timing of gene expression in development. We further show that enhancer transcription can regulate long-range interactions within complex regulatory landscapes. We propose that ncRNAs locally modulate regulatory element activity in cis to shape genome organization and orchestrate the temporal control of gene expression in development.
Physical Review Letters
What Is the Maximum Density of Microwave Control Lines in a Superconducting Quantum Computer?
Article | Quantum Information, Science, and Technology | 2026-09-09 06:00 EDT
Nikolas Klemola Tango, Mar Francis De Guzman, Slawomir Simbierowicz, Yuri Henriqson Accordi, Ville Nuutinen, Massimo Borrelli, and Russell E. Lake
Scaling up superconducting quantum computers requires denser control wiring, introducing microwave crosstalk along the entire cryogenic signal path rather than only near the chip. Here, we introduce a framework that combines microwave transmission-line theory with a quantum Hamiltonian description t…
Phys. Rev. Lett. 137, 110202 (2026)
Quantum Information, Science, and Technology
Generating Honeycomb-Structured Entanglement with a Reconfigurable Spatially Structured Pump
Article | Quantum Information, Science, and Technology | 2026-09-09 06:00 EDT
Yu Guo, Xiaozhou Pan, Shengshuai Liu, Guanjun Zeng, Kai Zhang, and Jietai Jing
Multipartite entanglement is a fundamental resource for quantum information processing. Various degrees of freedom of light, such as time, frequency, and space, have been widely exploited to create large-scale entangled quantum sources, enhancing information transmission capacity. Here, we demonstra…
Phys. Rev. Lett. 137, 110203 (2026)
Quantum Information, Science, and Technology
Network-Irreducible Multiparty Entanglement in Quantum Matter
Article | Quantum Information, Science, and Technology | 2026-09-09 06:00 EDT
Liuke Lyu, Pedro Lauand, and William Witczak-Krempa
We show that the standard approach to characterize collective entanglement via genuine multiparty entanglement (GME) leads to an area law in ground and thermal Gibbs states of local Hamiltonians. To capture the truly collective part one needs to go beyond this short-range contribution tied to interf…
Phys. Rev. Lett. 137, 110204 (2026)
Quantum Information, Science, and Technology
Local Reversibility and Divergent Markov Length in $1+1$-D Directed Percolation
Article | Quantum Information, Science, and Technology | 2026-09-09 06:00 EDT
Yu-Hsueh Chen and Tarun Grover
Recent progress in open many-body quantum systems has highlighted the importance of the Markov length, the characteristic scale over which conditional correlations decay. It has been proposed that nonequilibrium phases of matter can be defined as equivalence classes of states connected by short-time…
Phys. Rev. Lett. 137, 110402 (2026)
Quantum Information, Science, and Technology
Practical Roadmap to Measurement-Altered Criticality in Rydberg Arrays
Article | Quantum Information, Science, and Technology | 2026-09-09 06:00 EDT
Stephen Naus, Yue Liu, Sara Murciano, Pablo Sala, Manuel Endres, and Jason Alicea
Weak measurements have been predicted to dramatically alter universal properties of quantum critical wave functions, though experimental validation remains an open problem. Here we devise a practical scheme for realizing measurement-altered criticality in a chain of Rydberg atoms tuned to Ising and …
Phys. Rev. Lett. 137, 110403 (2026)
Quantum Information, Science, and Technology
Fundamental Limits on Quantum Bit Error Rate and Distance in Quantum Key Distribution
Article | Quantum Information, Science, and Technology | 2026-09-09 06:00 EDT
Stefano Pirandola
Quantum key distribution (QKD) enables information-theoretic secure communication, yet its ultimate tolerance to noise and achievable transmission distance remain fundamentally constrained. We establish the maximum quantum bit error rate (QBER) compatible with secure QKD and derive corresponding upp…
Phys. Rev. Lett. 137, 110801 (2026)
Quantum Information, Science, and Technology
Experimental Demonstration of Asynchronous Measurement-Device-Independent Quantum Cryptographic Conferencing
Article | Quantum Information, Science, and Technology | 2026-09-09 06:00 EDT
Haotao Zhu, Zhenhua Li, Shuai Zhao, Xiaodan Lyu, Shihao Ru, Yizhi Huang, Zitong Xu, Rui Qu, and Weibo Gao
Quantum networks enable a variety of quantum information processing tasks, where multiuser quantum communication is one of the important objectives. Quantum cryptographic conferencing (QCC) serves as an essential solution to establish secure keys to realize secure multiuser communications. However, …
Phys. Rev. Lett. 137, 110802 (2026)
Quantum Information, Science, and Technology
Updated Constraints on the Injection Energy of Positrons Generating the Galactic 511 keV $γ$-Ray Line
Article | Cosmology, Astrophysics, and Gravitation | 2026-09-09 06:00 EDT
Souradeep Das, Mark R. Krumholz, Roland M. Crocker, Thomas Siegert, and Laura Eisenberger
Even 50 years after the discovery of a positron annihilation line from the inner Galaxy, no class of astrophysical sources has emerged as a definitive explanation for both the emission morphology and flux. Positrons produced by dark matter annihilation or decay have been proposed, but the mass of an…
Phys. Rev. Lett. 137, 111003 (2026)
Cosmology, Astrophysics, and Gravitation
Not-Quite-Primordial Black Holes
Article | Cosmology, Astrophysics, and Gravitation | 2026-09-09 06:00 EDT
Wenzer Qin, Soubhik Kumar, Priyamvada Natarajan, and Neal Weiner
We propose a new mechanism for the formation of seeds of supermassive black holes at early cosmic epochs. Our scenario explores density fluctuations that are enhanced relative to expectations, but with amplitudes that are not large enough to form primordial black holes, and that can still lead …
Phys. Rev. Lett. 137, 111004 (2026)
Cosmology, Astrophysics, and Gravitation
Six-Loop Gravitational Interactions at the Sixth Post-Newtonian Order
Article | Cosmology, Astrophysics, and Gravitation | 2026-09-09 06:00 EDT
Giacomo Brunello, Manoj K. Mandal, Pierpaolo Mastrolia, Raj Patil, Matteo Pegorin, Jonathan Ronca, Sid Smith, Jan Steinhoff, and William J. Torres Bobadilla
We compute the gravitational interaction of two coalescing compact objects at sixth post-Newtonian order in the static limit, employing the diagrammatic approach within the effective field theory framework of general relativity. The calculation requires the evaluation of six-loop Feynman diagrams th…
Phys. Rev. Lett. 137, 111401 (2026)
Cosmology, Astrophysics, and Gravitation
Complete Computation of All Three-Loop Five-Point Massless Planar Integrals
Article | Particles and Fields | 2026-09-09 06:00 EDT
Dmitry Chicherin, Yu Wu, Zihao Wu, Yongqun Xu, Shun-Qing Zhang, and Yang Zhang
We calculate all three-loop, five-point, massless planar Feynman integral families in the dimensional regularization scheme. This is a new milestone in Feynman integral computations. The analysis covers four distinct families of Feynman integrals for this configuration, for all of which we derive th…
Phys. Rev. Lett. 137, 111603 (2026)
Particles and Fields
Regge Spectral Generator and Form Factors from Hard Exclusive Amplitudes in Holographic QCD
Article | Particles and Fields | 2026-09-09 06:00 EDT
Guy F. de Téramond, Stanley J. Brodsky, and Hans Günter Dosch
We show that the infinite tower of hard exclusive amplitudes in holographic light-front QCD leads to a spectral generator that encodes the full Regge spectrum. The construction assumes a Poisson distribution of Fock-state components, where represents the average parton multiplicity above th…
Phys. Rev. Lett. 137, 111903 (2026)
Particles and Fields
Quark and Gluon Tomography of the Helium-4 Nucleus
Article | Particles and Fields | 2026-09-09 06:00 EDT
V. Martínez-Fernández, B. Pire, P. Sznajder, and J. Wagner
QCD collinear factorization allows coherent hard exclusive reactions to reveal the quark-gluon structure of light nuclei, enabling their 3D tomography. In this Letter, we investigate elastic form factors and deeply virtual Compton scattering on a helium-4 target. We achieve unprecedented theoretical…
Phys. Rev. Lett. 137, 111905 (2026)
Particles and Fields
Investigation of Medium Modifications to $^{12}\mathrm{C}$ Structure Functions in the Resonance Region
Article | Nuclear Physics | 2026-09-09 06:00 EDT
S. Alsalmi et al. (The JUPITER Collaboration: JLab E02-109 E04-001 E06-009)
We present results from a high precision experimental study of the nuclear modification of the longitudinal () to transverse () structure function ratio for bound nucleons in the resonance region. The inclusive electron scattering cross sections were measured in Jefferson Lab Experimental Hall C…
Phys. Rev. Lett. 137, 112501 (2026)
Nuclear Physics
Spatially Resolved Temperature Measurement Using Rydberg Doppler Broadening Thermometry
Article | Atomic, Molecular, and Optical Physics | 2026-09-09 06:00 EDT
K. N. Trivedi, M. Carminati, Èlia Solé Cardona, T. Bonaccorsi, R. Donofrio, B. Bégoc, and O. Morsch
We demonstrate a technique for spatially resolved temperature measurement utilizing Rydberg Doppler broadening thermometry. This method employs two focused laser beams arranged perpendicularly to excite laser-cooled atoms from the ground state to a Rydberg state via a two-photon absorption process. …
Phys. Rev. Lett. 137, 113401 (2026)
Atomic, Molecular, and Optical Physics
Low-Entropy Arrays of Microwave-Shielded Molecules Prepared by Interaction Blockade
Article | Atomic, Molecular, and Optical Physics | 2026-09-09 06:00 EDT
Tijs Karman, Sebastian Will, and Zoe Z. Yan
Ultracold molecules are becoming an increasingly important technology for quantum simulation, computation, and sensing, but their state preparation in large, low-entropy arrays remains a key challenge. We propose to deterministically load single molecules into optical tweezer arrays or lattices from…
Phys. Rev. Lett. 137, 113402 (2026)
Atomic, Molecular, and Optical Physics
Hybrid Qubit-Oscillator Module from Motional States of Two Interacting Atoms
Article | Atomic, Molecular, and Optical Physics | 2026-09-09 06:00 EDT
Jaeyong Hwang, Tianrui Xu, Sean R. Muleady, Steven K. Pampel, Gur Lubin, Dawson P. Hewatt, Cindy A. Regal, and Ana Maria Rey
We propose a qubit-oscillator platform based on the motional states of two interacting atoms in an optical tweezer. By stroboscopically modulating an engineered trap with tunable anharmonicity, we implement a complete set of bosonic operations and their qubit-controlled counterparts with high fideli…
Phys. Rev. Lett. 137, 113403 (2026)
Atomic, Molecular, and Optical Physics
Measuring and Correcting Nanosecond Pulse Distortions in Quantum-Dot Spin Qubits
Article | Atomic, Molecular, and Optical Physics | 2026-09-09 06:00 EDT
Jiheng Duan, Fernando Torres-Leal, and John M. Nichol
Gate-defined semiconductor quantum dots utilize fast electrical control to manipulate spin and charge states of individual electrons. Electrical pulse distortions can limit control fidelities but are difficult to measure at the device level. Here, we use detuning-axis pulsed spectroscopy to characte…
Phys. Rev. Lett. 137, 113601 (2026)
Atomic, Molecular, and Optical Physics
Programmable Branched Flow of Light
Article | Atomic, Molecular, and Optical Physics | 2026-09-09 06:00 EDT
Shan-shan Chang, Daxing Xiong, Ze-huan Zheng, Li-Wei Wang, Yan-qing Lu, Lu-Jian Chen, Jian-Hua Jiang, and Jin-hui Chen
Wave transport in disordered media is obscured by complex multiple scattering, yet prior experiments lack precise, reconfigurable control over microscopic disorder potentials. Using photoaligned nematic liquid crystals, we implement programmable spatial optical potentials to deterministically tailor…
Phys. Rev. Lett. 137, 113802 (2026)
Atomic, Molecular, and Optical Physics
Observation of Hexagonal Close-Packed Water Ice at Conditions in Ice Giant Planetary Interiors
Article | Physics of Fluids, Earth & Planetary Science, and Climate | 2026-09-09 06:00 EDT
Alexis Forestier, Gunnar Weck, Sandra Ninet, Gaston Garbarino, Mohamed Mezouar, Frédéric Datchi, and Paul Loubeyre
Researchers crushed and heated ice between diamond anvils to confirm the existence of a phase of ice that could be present in the warm mantles of ice giants.
Phys. Rev. Lett. 137, 114101 (2026)
Physics of Fluids, Earth & Planetary Science, and Climate
Waiting Time Distribution and Multifractality Analysis of Solar Flares
Article | Plasma and Solar Physics, Accelerators and Beams | 2026-09-09 06:00 EDT
S. Mestici, M. Berretti, F. Berrilli, and R. Benzi
The statistical properties of solar flare occurrence are critical for understanding coronal energy release, yet the nature of their underlying dynamics remains heavily debated. Analyzing over two decades of soft x-ray observations from a comprehensive geostationary operational environmental satellit…
Phys. Rev. Lett. 137, 115201 (2026)
Plasma and Solar Physics, Accelerators and Beams
Moiré-Modulated $\mathrm{Γ}$ Valley in Twisted Bilayer and Twisted Double-Bilayer ${\mathrm{MoTe}}_{2}$
Article | Condensed Matter and Materials | 2026-09-09 06:00 EDT
Wanying Chen, Hongyun Zhang, Jinxi Lu, Yu Gu, Qiyun Xu, Fei Wang, Xuanxi Cai, Jiansong Li, Jiayong Xiao, Rui Chen, Kenji Watanabe, Takashi Taniguchi, Jose Avila, Pavel Dudin, Matthew D. Watson, Pu Yu, Shengwei Jiang, Wenhui Duan, Tingxin Li, Chong Wang, and Shuyun Zhou
Angle-Resolved Photoemission Spectroscopy measurements on twisted bilayer and double-bilayer MoTe₂, combined with theory, reveal remote electronic bands that follow twist-induced lattice relaxation, establishing a direct link between atomic reconstruction and electronic structure in moiré semiconductors.
Phys. Rev. Lett. 137, 116401 (2026)
Condensed Matter and Materials
Engineering Quantum Criticality in the Integer Quantum Hall Regime through a Screening Layer
Article | Condensed Matter and Materials | 2026-09-09 06:00 EDT
C. T. Tai, P. T. Madathil, A. Gupta, L. N. Pfeiffer, K. W. Baldwin, and M. Shayegan
A universal scaling exponent corresponds to a dynamic exponent in the integer quantum Hall regime in a bilayer GaAs quantum well device.
Phys. Rev. Lett. 137, 116501 (2026)
Condensed Matter and Materials
Hyperspin Altermagnets
Article | Condensed Matter and Materials | 2026-09-09 06:00 EDT
Hai-Yang Ma, Yuanchang Li, Hu Xu, Shengbai Zhang, and Jin-Feng Jia
The behavior of spin quantum in -space is key to identifying altermagnets (AMs) as the third kind of fundamental collinear magnetism. By contrast, noncollinear magnets--though abundant in nature--lack well-defined spin quantum numbers, and the resulting spin textures are often highly complex, which l…
Phys. Rev. Lett. 137, 116704 (2026)
Condensed Matter and Materials
Autferroics-Based True Random Number Generators with Enhanced Performance
Article | Condensed Matter and Materials | 2026-09-09 06:00 EDT
Jun-Jie Zhang, Shuai Dong, and Boris I. Yakobson
Physical entropy-driven true random number generators are essential for emerging probabilistic computing paradigms, but conventional implementations based on magnetic tunneling junctions have reached their performance plateaus limited by inherent tradeoffs and weak tunability. Here, autferroics, a s…
Phys. Rev. Lett. 137, 116801 (2026)
Condensed Matter and Materials
Ordered Electromagnetic Dissipation via Admittance Scaling
Article | Condensed Matter and Materials | 2026-09-09 06:00 EDT
Yingjian Sun, Haoran Liang, Yixing Huang, Weijie Li, and Ying Li
A long-standing challenge in electromagnetic dissipative systems is that dissipation and phase evolution are fundamentally entangled through the underlying admittance dynamics, leading to oscillatory and path-dependent response trajectories under tuning. In this Letter, we identify an admittance-sca…
Phys. Rev. Lett. 137, 116903 (2026)
Condensed Matter and Materials
Enhanced Terahertz Emission Enabled by Circular Photogalvanic Effect
Article | Condensed Matter and Materials | 2026-09-09 06:00 EDT
Da Tian, Lei Wang, Zhongqiang Chen, Anke Song, Kankan Xu, Zhikang Jiang, Jialiang Huang, Wei Zhang, Lei Wang, Junwei Liu, Qiannan Li, Zhichao Chen, Jingbo Wu, Kebin Fan, Huabing Wang, Jian Chen, Peiheng Wu, Caihong Zhang, Xuefeng Wang, Ke Xia, and Biaobing Jin
The circular photogalvanic effect in topological heterostructures offers a controllable route to enhanced, field-free terahertz emission, distinct from conventional spin-to-charge conversion.
Phys. Rev. Lett. 137, 116904 (2026)
Condensed Matter and Materials
Tensor-Network Markov-Chain Monte Carlo: Efficient Sampling of Three-Dimensional Spin Glasses
Article | Statistical Physics; Classical, Nonlinear, and Complex Systems | 2026-09-09 06:00 EDT
Tao Chen, Jing Liu, Youjin Deng, and Pan Zhang
Sampling equilibrium configurations of three-dimensional (3D) spin glasses with quenched disorder remains a fundamental challenge in statistical physics. The rugged energy landscape, pronounced critical slowing down, and intrinsic ergodicity breaking render standard Monte Carlo methods severely inef…
Phys. Rev. Lett. 137, 117101 (2026)
Statistical Physics; Classical, Nonlinear, and Complex Systems
Hybrid Topological Defects in Ferroelectric Nematic Fluids
Article | Polymers, Chemical Physics, Soft Matter, and Biological Physics | 2026-09-09 06:00 EDT
Shengzhu Yi, Chao Zhou, Zening Hong, Xinming Chu, Zhongjie Ma, Mingjun Huang, Satoshi Aya, Rui Zhang, and Qi-Huo Wei
We investigate the evolution of topological defects in polar fluids driven by discrete inversion symmetry breaking across the nematic-to-ferroelectric nematic phase transition. Using photopatterned surface alignment to prescribe well-defined initial defect configurations in the nematic phase, we tra…
Phys. Rev. Lett. 137, 118101 (2026)
Polymers, Chemical Physics, Soft Matter, and Biological Physics
Flocking Beyond One Species: Novel Phase Coexistence in a Generalized Two-Species Vicsek Model
Article | Polymers, Chemical Physics, Soft Matter, and Biological Physics | 2026-09-09 06:00 EDT
Eloise Lardet, Letian Chen, and Thibault Bertrand
A hallmark in natural systems, self-organization often stems from very simple interaction rules between individual agents. While single-species self-propelled particle systems are well understood, the behavior of binary mixtures with general alignment interactions remains largely unexplored with a f…
Phys. Rev. Lett. 137, 118303 (2026)
Polymers, Chemical Physics, Soft Matter, and Biological Physics
Physical Review X
General Quantum Circuit Framework for Extended Wigner’s Friend Scenarios: Logically and Causally Consistent Reasoning without Absolute Measurement Events
Article | 2026-09-09 06:00 EDT
V. Vilasini and Mischa P. Woods
Researchers develop a quantum circuit framework for extended Wigner's friend scenarios, resolving logical paradoxes by tracking Heisenberg cuts.
Phys. Rev. X 16, 031062 (2026)
arXiv
Hamiltonian fingerprints of a collective mode across the BCS-BEC crossover
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Collective excitations can survive profound changes in the microscopic degrees of freedom that generate them. We track a layer-odd collective response from an exact weak-coupling hybridisation anchor into the paired regime of an attractive Hubbard bilayer and find that its Hamiltonian sensitivities evolve in a manner consistent with a crossover from single-particle interlayer hybridisation towards collective pair superexchange. At weak coupling, an exact identity for identical tunnel-coupled layers fixes a relative-phase Gaussian kernel zero at $ 2t_h$ , independent of the intralayer hopping. Sign-free determinant quantum Monte Carlo reveals an interaction-driven softening of the many-body spectral scale without analytic continuation, while Gaussian response theory supplies the continuous pole interpretation and shows a shift from layer-density to relative-pair-phase character. In the paired regime, the characteristic response scale acquires a growing fractional sensitivity to the intralayer hopping and an interaction dependence partway towards the $ 1/U$ law. These results show how a collective excitation can be tracked across a fermion-to-composite-boson crossover while constraining changes in its microscopic drive.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Gases (cond-mat.quant-gas), Superconductivity (cond-mat.supr-con)
36 Pages, 6 Figs
The energetics of force errors in machine-learned molecular dynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Peng Kang, Da Wan, Shulin Bai, Vincent Michaud-Rioux, Zhen Li, Yu Liu, Lei Zheng, Li-Dong Zhao
The energetic effect of a force error depends on atomic motion. We establish a directional residual-work coefficient combining directional curvature mismatch with the spatial distribution of the residual response. For conservative potentials force-matched at an anchor, it determines the leading signed work at the first crossing of a small force-error budget. At a 474-atom lithium-electrolyte interface, predictions fixed before future reference evaluations differ from measurements by less than 4.6% of predicted work across 24 prescribed endpoints. Changing only the initial velocity direction at fixed structure and initial total kinetic energy reverses the force-work ranking. At the same admitted time of 0.25 fs, one direction gives an 11.6% larger maximum force residual but 36.1% less work. The reversal recurs at a second structure. The framework connects force tolerances to reference-energy transfer, providing a physical basis for potential assessment and adaptive reference allocation.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
24 pages, 8 figures
Two-magnon response from light scattering in altermagnets
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Shuyi Li, Lexu Zhao, Chunjing Jia
Altermagnetism is a recently established class of magnetic order that combines fully compensated moments with momentum-dependent spin splitting, yet identifying its spectroscopic fingerprints remains an open challenge. In this work, we investigate finite-momentum two-magnon excitations in a two-dimensional $ d$ -wave altermagnet by calculating the two-magnon light scattering intensity in different polarization channels. Using linear spin-wave theory and further incorporating the leading $ 1/S$ quantum corrections, we demonstrate that the characteristic magnon splitting of altermagnets shifts the upper edge of the two-magnon continuum and the corresponding spectral features to higher energy at $ \boldsymbol{X}=(\pi,0)$ relative to the conventional antiferromagnet, by an amount linear in the exchange anisotropy $ |\delta J_2|$ , while leaving the response at the Brillouin-zone center unchanged. Although magnon-magnon interactions strongly redistribute spectral weight toward lower energies, the energy scale associated with the high-energy momentum-selective reconstruction remains robust. The interactions additionally generate a pronounced low-energy two-peak structure that has no counterpart within linear spin-wave theory. At $ \boldsymbol{K}=(\pi/2,\pi/2)$ , we show that the interacting two-magnon resonance is twofold degenerate in the conventional antiferromagnetic phase, while a finite altermagnetic exchange anisotropy lifts this degeneracy, producing two peaks whose separation is linear in $ |\delta J_2|$ . The characteristic energy scales underlying both features are intrinsic to the two-magnon sector rather than to a specific scattering operator. These findings highlight the potential of finite-momentum two-magnon spectroscopy for identifying altermagnetic order in insulating magnets and motivate momentum-resolved resonant inelastic x-ray scattering studies of candidate altermagnetic materials.
Strongly Correlated Electrons (cond-mat.str-el)
Finite-Temperature Flat-Band Ferromagnetism in the Kagome Hubbard Model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Alon Strugatsky, Roser Valení, Jonas B. Profe
Kagome metals exhibit a rich interplay of topology, electronic correlations, and lattice dynamics. Recent discoveries of Kagome materials with a flat band near the Fermi level have revealed a variety of correlated electronic phases. However, elucidating their microscopic origin remains challenging, as realistic descriptions require accounting for multiple orbitals and competing interactions on an equal footing. To disentangle correlation effects from material-specific details and identify the essential physics of the flat-band regime, we study the single-orbital Kagome-Hubbard model at flat-band fillings using dynamical mean-field theory. We find strong signatures of flat-band ferromagnetism, consistent with exact and mean-field ground-state results. Moreover, we uncover an unconventional quasi-ordered phase in which a partially filled spin-polarized flat band pinned at the Fermi level gives rise to persistent local spin fluctuations down to zero temperature, in striking contrast to the classical behavior expected for a conventional ferromagnet. Our results demonstrate that these anomalous fluctuations are an intrinsic consequence of the flat-band degeneracy and establish a minimal framework for understanding correlation effects in flat-band Kagome systems.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 3 figures
Distinguishability Transitions from Global Quantum Snapshots
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Catherine McCarthy, Sarang Gopalakrishnan, Romain Vasseur
Quantum states generated by generic time evolution are locally featureless: local measurements return random outcomes that are identical for all states. However, global snapshots in the computational basis are surprisingly effective at distinguishing between quantum states. We explore the ability of Bayesian classifiers to discriminate between many random quantum states using a small number of measurement outcomes. We identify a phase transition in the ability of the classifier to distinguish between $ k$ candidate states with $ m$ shots controlled by the variable $ x = m / \ln k$ , and derive the threshold value $ x_c$ . We extend our results to low-depth circuits near the onset of anti-concentration, as well as to noisy circuits and phase-random states.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
Transient and universal regimes in quantum reaction-transport kinetics
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Hossein Hosseinabadi, Roderich Moessner
Quantum reaction-transport systems consist of coherently propagating particles that irreversibly react upon encounter. Their relaxation is commonly classified as reaction-limited or transport-limited, depending on the relative timescales of reaction and particle transport. We show that this expectation fails in low dimensions by studying the quantum binary annihilation, $ A+A \to \emptyset$ , where reaction processes acquire singular fluctuation corrections below the upper critical dimension $ D_c=2$ . Consequently, fluctuations dominate the asymptotic kinetics for $ D<2$ . In one dimension, they render mean-field relaxation transient and drive the system toward a transport-limited regime with $ n\sim t^{-1/2}$ , governed by a quantum-Zeno scale even for arbitrarily weak loss. At $ D=2$ , the kinetics acquires logarithmic corrections, whereas above two dimensions mean-field scaling is asymptotically restored. At and below the upper critical dimension, mean-field behavior can nevertheless persist over parametrically long crossover times before the asymptotic fluctuation-dominated regime emerges. We also show that the same fluctuations generate effective elastic collisions despite the absence of microscopic coherent interactions. In $ D>1$ , these collisions redistribute momentum populations and are parametrically faster than losses in the transport-limited regime, allowing the system to approach a quasi-stationary thermal state.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
19 pages, 6 figures
Implicit size dependence of the valence electron concentration criterion in high-entropy alloys
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
The valence electron concentration (VEC) is the most widely used predictor of FCC against BCC stability in high-entropy alloys (HEAs), yet it is a compositional average carrying no information about atomic size. Using the macroscopic atom model, we show that the mixing enthalpy is almost size-blind, shifting by less than 6% even when constituent volumes differ by a factor of 2, so that size can act only on the electron count. That action equals exactly the covariance of the atomic surface $ V^{2/3}$ with the valence electron count, divided by its mean. This covariance is not free. Volume and valence are strongly anti-correlated across the elements used to build HEAs, so the size-corrected count is an affine rescaling of VEC over 265 characterized alloys and improves no prediction. VEC already encodes atomic size, which explains its success and locates its failure among large, electron-rich elements. Chemistry sets the enthalpy through one switch element.
Materials Science (cond-mat.mtrl-sci)
Non-Hermitian topology in driven-dissipative systems: correspondence with quantum correlations and a resource for entanglement
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Niladri Chakraborty, Clara C. Wanjura
Directional amplification, in which signals are amplified selectively depending on their propagation direction, is a key resource for quantum information processing and stands in one-to-one correspondence with non-trivial non-Hermitian topology. So far, this correspondence has concerned the mean fields, and thus classical response. Here we turn to the quantum fluctuations, giving access to correlations and entanglement. For phase-preserving amplifiers, we derive analytic expressions for the normal and anomalous correlations, showing that non-trivial topology produces correlations that grow exponentially with the distance between modes and approach the largest values compatible with the uncertainty relations. The associated correlation length diverges at the topological phase transition. Entanglement nonetheless remains local, set by the competition between normalised anomalous correlations and the asymmetry of the mode occupations. For the bosonic Kitaev chain, a phase-sensitive amplifier, the system instead splits into two halves that are internally fully correlated yet mutually uncorrelated. Our work prepares the ground for exploring the quantum properties of non-Hermitian topological systems with state-of-the-art platforms such as cavity optomechanics and superconducting circuits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics), Quantum Physics (quant-ph)
main text: 9 pages, 5 figures. Comments welcome!
Phase stability and mechanical response of Ag-interlayered Al/Cu resistance spot-welded joints
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Shuang Lin, Kyubok Lee, Jiahui Ye, Ho Kwon, Shun-Li Shang, Allison M. Beesea, Xun Liu, Jingjing Li, Zi-Kui Liu
Dissimilar Al/Cu joints are essential to battery-pack assemblies; however, their mechanical strength is limited by brittle Al-Cu intermetallic compounds (IMCs) such as Al2Cu and Al4Cu9. Interlayer strategies to suppress these phases remain largely empirical, lacking a predictive framework linking interlayer chemistry to the phases that form and to their intrinsic mechanical character. Here an Ag interlayer is introduced and combines computational thermodynamics, first-principles calculations, microstructural characterization, and mechanical testing into a single self-consistent description of the joint. CALculation of PHAse Diagrams (CALPHAD) equilibrium and Scheil simulations predict the solidification path of the Al-rich Al-Ag fusion zone and explain why Cu incorporation is limited when Ag is present; energy-dispersive X-ray spectroscopy (EDS) and electron backscatter diffraction (EBSD) confirm an FCC Al-Ag solid solution as the dominant constituent. First-principles phonon calculations within the quasiharmonic approximation yield finite-temperature entropy and Gibbs energy, benchmarked against CALPHAD, while elastic constants assess ductility via the Pugh criterion (i.e., the bulk/shear (B/G) modulus ratio). All Al-Ag phases, including the observed solid solution, exceed the Pugh threshold of 1.75, whereas the targeted Al-Cu IMCs do not, giving a mechanistic basis for the interlayer’s effectiveness. This microstructural change translates into improved performance: nominal strength rises from 47.9 to 67.4 MPa. Nanoindentation gives a fusion-zone reduced modulus of 82.8 GPa (Young’s modulus 82.0 GPa), versus a calculated 0 K Voigt-Reuss-Hill value of 71.4 GPa. The present work establishes a transferable CALPHAD, first-principles, and experiment workflow for rational interlayer selection in dissimilar-metal joining.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
31 pages, 13 figures and 1 table
Tuning Charge Density Wave transitions through lattice strain in NbSe3
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Antoine Gallo Frantz, Aleksander Sinchenko, Luc Ortega, Pavel Grigoriev, Vladislav Kochev, Pierre Godard, Pierre Olivier Renault, Dominique Thiaudiere, David Le Bolloch, Vincent Jacques
The Charge Density Wave (CDW) state is a perfect example of a combined structural and electronic state, both characterized by a periodic lattice distortion and an electronic modulation of condensed electrons, resulting from electron-phonon coupling. They are thus prone to be tuned by lattice strain. NbSe3 is a prototypical example of CDW states, with a chain-like structure displaying two CDWs at 145K and 59K, with wavevectors along and inclined with respect to the chain axis b. Here, we report on the evolution of the lattice structure and CDW properties in the quasi-one-dimensional charge-density-wave system NbSe3 under tensile stresses applied along and perpendicular to the chains axis b by a combination of X-ray diffraction and transport measurements. We find that the lattice structure show exotic Poissons coefficients and strongly anisotropic Youngs moduli while the evolution of the electrical resistance demonstrates shifts of both charge-density-wave critical temperatures that are strongly correlated with the lattice parameters. The two CDW transitions display different behaviours under applied stresses, and suggest that a modification of the band curvature leads to the observed transport signatures.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
9 pages, 10 figures
Emergent Electronic Bond-Order Wave in a Quasi-One-Dimensional Chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Honghao Wang, Tristan R. Cao, Pedro Schlottmann, Gang Cao
Collective order is notoriously difficult to stabilize in one dimension, where strong fluctuations suppress symmetry-breaking states. Here we report the emergence of an electronic bond-order wave (BOW) in the quasi-one-dimensional (1D) material Ba9Rh8O24, in which structural bonds become active electronic degrees of freedom that overcome 1D fluctuations to establish long-range order. Single-crystal X-ray diffraction uncovers a striking inversion of inequivalent Rh-Rh bonds across a transition TA = 180 K, where short and long bonds interchange their identities rather than undergoing conventional Peierls dimerization. This bond inversion coincides with a heat-capacity anomaly and a profound reorganization of the dielectric response with strong suppression of dielectric loss upon cooling. The BOW exhibits strongly nonlinear, frequency-dependent I-V characteristics, clockwise hysteresis, and nonvolatile memristive switching. These findings uncover an unprecedented transformation from a dynamic bond liquid to a rigid yet electrically reconfigurable BOW, establishing bond-centered electronic order as a new organizing principle for 1D quantum matter.
Strongly Correlated Electrons (cond-mat.str-el)
5 figures
A force model for dense granular flows and particle segregation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
M.P. van Schrojenstein Lantman
Dense granular flows are a common occurrence throughout nature and industry, but still exhibit phenomena that are not fully understood. One of these phenomena is the segregation of particles that constitute a dense granular flow, where particles separate due to differences in properties such as size and density. This work approaches segregation from a new perspective by developing a force model for a single particle based on the observation that there are two opposing drag forces acting on the particle. Validation of the model in mono-disperse flows reveals a family of velocity profiles, including a Bagnold profile. Further validation is done by comparing with known particle scaling laws in literature. The force model shows that the mechanism of segregation is always present in dense granular flows and that mono-disperse flows are a unique case where it is not distinctly visible. The insights in this paper prove a fundamental new way of thinking about dense granular flows and its individual particles, opening the field for new research directions.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Quantum Phase Transitions and Fractional Quantized Anomalous Hall Insulators in Rhombohedral Graphene
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Zach Hadjri, Xinlei Yue, Tonghang Han, Yuxuan Yao, Zhengguang Lu, Shenyong Ye, Junseok Seo, Jixiang Yang, Kenji Watanabe, Takashi Taniguchi, Liang Fu, Ady Stern, Long Ju
Fractional quantum anomalous Hall effect (FQAHE) has been discovered in twisted MoTe$ _2$ and rhombohedral graphene/hBN moiré superlattices. Such van der Waals heterostructures feature a tuning knob of gate displacement field $ D$ , which is absent from the conventional fractional quantum Hall systems in two-dimensional electron gases. $ D$ plays a critical role in engineering FQAHE and other emergent quantum states and provides an exciting new opportunity to explore their quantum phase transitions. However, the microscopic details of such transitions and temperature-dependent transport have remained mostly elusive. Here we report systematic resistance measurements in rhombohedral pentalayer graphene/hBN moiré superlattices. We found that the displacement field-driven phase transitions between Composite Fermi liquid, Fermi liquid, Fractional Chern insulators, and insulating states are described by semi-circle relations of the longitudinal and transverse resistivities (or conductivities), largely unexplored in the fractional quantum Hall systems. This agrees with a spatially separated two-phase picture for the phase transitions and further indicates a new insulator phase–fractional quantized anomalous Hall insulator. By comparing the temperature-dependence of longitudinal resistance with the thermal activation model, we estimated the transport gap sizes in three fractional Chern insulator states. Our work shed light on the quantum and temperature evolutions of fractional Chern insulator states–providing necessary background for anyon-braiding and gate-defined junctions in rhombohedral graphene.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
27 pages, 13 figures
Origin of Flat Bands and Role of Electron Correlation in Lutetium Hydrides
New Submission | Superconductivity (cond-mat.supr-con) | 2026-09-10 20:00 EDT
Anmol Lamichhane, Adam Denchfield, Hyeondeok Shin, Panchapakesan Ganesh, Russell J. Hemley, Hyowon Park
Lutetium hydrides (LuH$ _x$ , $ 1.75 \leq x \leq 3$ ) form a diverse series of phases, several of which superconduct under pressure. Characterizing their electronic properties has remained challenging owing to a high propensity for hydrogen defect formation, and recent angle-resolved photoemission (ARPES) measurements reveal puzzling flat-band regions that position these materials as candidates where superconductivity and flat-band physics may intersect. Here, by combining density functional theory, dynamical mean-field theory, and the constrained random-phase approximation, we uncover the microscopic origin and correlation nature of these flat bands. Across all compositions, the screened on-site Coulomb interaction is larger for H-s states than for Lu-$ d$ states due to compact hydrogen orbitals. Nevertheless, these systems remain weakly correlated metals: the nearly filled H-$ s$ shell admits little charge fluctuation, so its large interaction acts as a static level shift rather than a source of correlation. Although hydrogen primarily occupies tetrahedral sites at $ x=2$ , we discover that anti-site defects–where hydrogens occupy slightly unfavorable octahedral sites–generate both the ARPES flat-band features and the low-energy optical absorption peak, attesting to the usual defective nature of such materials in experimental samples. We further find that correlation strength is governed primarily by hydrogen orbital filling at these sites rather than the interaction magnitude itself. Consequently, we identify hydrogen orbital filling as the fundamental organizing principle dictating correlation and low-energy flat-band physics in lutetium hydrides.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
12 pages, 6 figures
Temperature-induced effective topology in many-body ultracold atomic quantum systems
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-09-10 20:00 EDT
Nitya Cuzzuol, Michele Miotto, Arianna Montorsi, Giacomo Valtolina, Luca Barbiero
Ultracold atomic quantum systems offer an unprecedentedly powerful platform for exploring interacting symmetry-protected topological phases. Here, we show that their characteristic control over temperature provides a resource for engineering effective topological regimes with no zero-temperature counterpart. Employing finite-temperature matrix-product-state calculations, we investigate experimentally accessible Hamiltonians - the interacting bosonic Su-Schrieffer-Heeger and spin-1 XXZ chains - that host a topological phase at zero temperature, as well as a fermionic dipolar ladder model whose ground state exhibits no topological order. By tracking complementary topological markers, we identify an intriguing mechanism rooted in the structure of the zero-temperature phase diagrams: in finite-size systems, excitation gaps with different magnitudes define an intermediate-temperature window where the correlations associated with the lower gap are suppressed, while those protected by the larger gap persist. This enables the emergence of effective finite-temperature regimes exhibiting topological features that are either absent or qualitatively different from those at zero temperature. Our results establish a novel route toward exploring effective topological phases in ultracold atomic quantum systems.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
Prethermal ripplons in quenched binary Bose-Einstein condensates
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-09-10 20:00 EDT
Yanda Geng, Stephen Eckel, Gretchen K. Campbell, Ian B. Spielman
Prethermal states–long-lived quasi-equilibrium configurations–occur in a wide range of physical systems that exhibit fast dephasing or reconfiguration followed by slow relaxation towards thermal equilibrium. We experimentally studied the 1D interface between immiscible 2D Bose-Einstein condensates (BECs); following a quench, the interfacial capillary waves (ripplons) quickly relaxed into a long-lived prethermal state characterized by a persistent non-equipartition of energy, evoking the classic Fermi-Pasta-Ulam-Tsingou problem. We directly measured the interface’s height profile as it evolved in time, identified the contribution of individual ripplon modes, and find that, though their individual amplitudes are thermally distributed, they are not in thermal equilibrium–high-momentum modes rapidly equilibrated with the bulk phonon modes of the 2D BEC, while lower momentum modes remained at elevated temperatures, forming a long-lived prethermal configuration for the whole system. We attribute this to kinematic isolation: the absence of energy- and momentum-conserving relaxation processes in our system at ultracold temperature.
Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech)
5 pages main text (4 figures) + 5 pages SM (3 figures)
High-pressure elastic properties of GeO2 polymorphs up to 120 GPa
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Gulshan Kumar, Sumit Ghosh, Sharad Babu Pillai, Rajkrishna Dutta
We systematically investigated the phase stability and pressure dependence of the elastic properties of four GeO2 polymorphs: rutile-, CaCl2-, alpha-PbO2-, and pyrite-type phases using theoretical calculations based on density functional theory. The elastic constants were calculated at 5 GPa intervals within the respective stability ranges of the four phases, as determined from static enthalpy calculations. We further employed a classical strain-coupled Landau free-energy expansion to describe the pressure evolution of the elastic response associated with the rutile- to CaCl2-type transition and to elucidate the origin of the elastic softening near the transition. The rutile- to CaCl2-type phase transition is consistent with a Landau-type second-order transition, with a critical pressure of 14.6 GPa obtained from the strain-based analysis. As the transition pressure approaches, elastic softening develops in the rutile-type phase, resulting in anomalous pressure dependence of the bulk and shear modulus. The calculated elastic-wave anisotropy increases markedly near the transition, primarily due to the rapid reduction in shear-wave velocity, reaching a maximum of approximately 122% at 22.5 GPa. Following the transition, the anisotropy decreases sharply in the CaCl2-type phase and exhibits a discontinuity at the CaCl2-type/alpha-PbO2 -type phase boundary. The higher-pressure alpha-PbO2- and pyrite-type phases exhibit comparatively weak pressure dependence of anisotropy, with a small discontinuity at their respective phase transition boundaries. The pyrite-type phase has the lowest anisotropy, reaching only approximately 4-5% at high pressure, consistent with the high-symmetry cubic structure and nearly isotropic elastic-wave propagation.
Materials Science (cond-mat.mtrl-sci)
Exact asymptotic equivalence between precisions of record-times and integrated currents
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
We establish an exact equivalence between the fluctuations of integrated currents and the temporal statistics of current record events in continuous-time Markov jump processes. Specifically, we show that, under minimal assumptions, the Fano factor of an integrated current coincides exactly with the squared coefficient of variation of the inter-record waiting times. This result is obtained by showing that inter-record times induce a renewal structure, since each record event resets the system to a fixed state, and that their generating function can be expressed exactly in terms of a combinatorial organization governed by Narayana numbers. The equivalence extends previous results obtained for unicyclic networks to arbitrary finite-state graphs and provides a unified representation of current fluctuations in terms of record-time observables. The results are derived within a purely probabilistic framework and clarify the structural origin of current precision in terms of first-passage-like event statistics.
Statistical Mechanics (cond-mat.stat-mech)
12 pages, 3 figures
Light-Driven Ultrafast Control of Time-Reversal Symmetry in SrTiO3
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
In Hyeok Choi, Sergei Urazhdin, Shivasheesh Varshney, Seung Gyo Jeong, Bharat Jalan, Keith A. Nelson
Light-driven control of material symmetry enables the engineering of phenomena forbidden in equilibrium. Although electromagnetic fields have been used to break time-reversal symmetry, its dynamic control on ultrafast timescales in nonmagnetic insulating oxides remains virtually unexplored. Here, we demonstrate simultaneous magnetic symmetry lowering and timereversal-symmetry breaking in cubic SrTiO3 driven by an off-resonant, elliptically polarized THz pulse. Second harmonic generation (SHG) polarimetry reveals emergent SHG circular dichroism inconsistent with third-order nonlinear processes under cubic m3m symmetry. The SHG polar patterns exhibit mirror-symmetry breaking, indicating a transient reduction to tetragonal 4/mm’m’ magnetic symmetry. Furthermore, the SHG response scales linearly with the angular momentum of THz pulse, providing direct evidence for THz-field-induced timereversal-symmetry breaking. These results establish a direct pathway for ultrafast symmetry control in non-magnetic oxides, enabling dynamic manipulation of emergent phases on ultrafast timescales.
Materials Science (cond-mat.mtrl-sci)
Gap-controlled thermalization in a SSH model version of the Fermi-Pasta-Ulam-Tsingou chain
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
José A. Aké, Gerardo G. Naumis
In classical anharmonic lattices, the resonance structure driving nonlinear mode mixing is reshaped by band gaps. However, it remains unclear whether a spectral gap hinders or promotes long-time thermalization. Here we study a dimerized Fermi-Pasta-Ulam-Tsingou chain - a classical SSH model analogue with alternating spring constants - and quantify how the acoustic-optical gap controls relaxation under alpha-type (cubic) nonlinearity. Tracking modal energies and spectral entropy via long-time symplectic simulations, we find a sharp isolation threshold when the dimerization strength reaches half its maximum value, set by the onset of the first umklapp process that allows two zone-boundary acoustic phonons to fuse into a zone-center optical phonon; below this threshold, three-wave acoustic-acoustic-optical scattering activates the optical branch on timescales of order 1e4 oscillation periods, while above it the bands remain dynamically isolated. We further show that boundary conditions reshape this picture, producing long-lived sticky states for specific mode excitations. These results establish the phononic gap as a tunable, momentum-selective filter for nonlinear energy transport, suggesting a general route to controlling thermalization in dimerized or topologically gapped nonlinear lattices.
Statistical Mechanics (cond-mat.stat-mech)
Under review for Physical Review E
Topological instability and reentrant crystallization in active solids
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Zory Davoyan, Aditya Jha, Anton Souslov
We extend the KTHNY theory of defect-mediated melting in two dimensions to the case of active solids exhibiting both non-reciprocal (odd) elasticity and Cosserat (micropolar) coupling. For perturbatively small values of non-reciprocity, melting still proceeds via defect unbinding, but the melting temperature shifts due to activity. However, at a threshold value of non-reciprocity, we discover a qualitatively distinct mechanism for 2D melting, which we call topological instability. This melting occurs through the proliferation of defect pairs at any temperature. We use a combination of field theory and simulations to characterize this zero-temperature transition in terms of the defect-pair fugacity. Surprisingly, for higher activity values, we find reentrant crystallization, where the quasi-long-range order survives even at temperatures for which the equilibrium crystal would melt. Although active solids present one realization of this topological instability, we envision core-energy-driven defect proliferation as a generic and unexplored route for two-dimensional melting.
Statistical Mechanics (cond-mat.stat-mech)
Intrinsic (valley) thermal Hall conductivity of phonons in graphene for integer quantum Hall phases
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
We calculate the intrinsic contribution to the (valley) thermal Hall conductivity of phonons in (Semenoff-gapped) graphene in the quantum Hall regime where bulk electron thermal transport is suppressed. The (valley) thermal Hall transport of phonons considered here originates from a phonon (valley) Hall viscosity induced by electron (valley) Hall conductivity and viscosity via geometric electron-phonon coupling. The so generated phonon (valley) Hall viscosity is identified with the emergent (valley) Hall viscosity recently introduced in \textit{Phys. Lett. A} \textbf{595}, 132096 (2026). While our calculations refer to graphene, they may very well be generalized to other Dirac materials like group-VI transition metal dichalcogenides. We discuss the prospect of measuring the phonon thermal Hall conductivity in graphene-based heterostructures and estimate the corresponding valley response induced by electrons in the inversion symmetry broken phase.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages
The Role of Concentration in Determining NaCl Nucleation Mechanism: A Story of Pathways Coexistence
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Deciphering the microscopic details of crystal nucleation remains a key open problem in chemical physics. For aqueous sodium chloride (NaCl), the extent to which nucleation involves amorphous ion aggregation, and the supersaturation regime in which two-step-like behavior emerges, remains actively debated. In this work, we examine NaCl nucleation at 12, 13, and 14 mol/kg ($ S = 3.2, 3.5, 3.8$ ) using unbiased path sampling with $ \infty$ RETIS. Through a combination of reaction coordinate analysis, joint and conditional probability distributions, diffusion tensor analysis, and conditional free energy landscapes, we identify nucleation pathways without a priori mechanistic assumptions. While all concentrations are governed by the same reaction coordinate, indicating that nucleus growth and structural ordering are central to crossing the barrier, the nature of reactive trajectories changes with supersaturation. At lower concentrations, nucleation mainly occurs via tightly coupled increases in cluster size and ordering, compatible with a one-step-like mechanism. As concentration increases, amorphous aggregation becomes increasingly decoupled from crystallization, and pathways involving substantial amorphous growth prior to crystallization become progressively more probable. Importantly, these pathways coexist within a single broad reaction channel rather than proceeding through distinct metastable intermediate states. Together, these results reconcile earlier, contradictory reports on NaCl nucleation mechanisms and support a view of nucleation as an ensemble of competing reactive pathways whose relative probabilities vary continuously with supersaturation. More broadly, our findings illustrate that substantial mechanistic diversity can emerge within a classical nucleation framework, without requiring distinct non-classical descriptions.
Statistical Mechanics (cond-mat.stat-mech), Chemical Physics (physics.chem-ph)
24 pages, 10 figures
Comprehensive molecular dynamics study of the dynamical properties of a dense binary hard-sphere mixture
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
Sabry G. Moustafa, Andrew J. Schultz
We present an extensive molecular dynamics (MD) study of the dynamical properties of a binary hard-sphere fluid over a wide range of packing fractions, $ \phi \approx 0.357-0.582$ . The self-diffusivity, $ D$ , and shear viscosity, $ \eta$ , are computed using an efficient implementation of the Einstein–Helfand method. The finite-size effects in $ D$ scale as $ 1/N^\alpha$ , with $ \alpha$ increasing from approximately $ 1/3$ to $ 3/4$ with increasing $ \phi$ , whereas those in $ \eta$ are negligible except for $ \phi \gtrsim 0.554$ , where they scale as $ 1/N$ . The data are then extrapolated to the thermodynamic limit to obtain $ D_{\infty}$ and $ \eta_{\infty}$ . Both coefficients show a super-Arrhenius dependence on $ \phi$ for dense states, accompanied by a breakdown of the Stokes–Einstein relation. Although both $ D_{\infty}(\phi)$ and $ \eta_{\infty}(\phi)$ data are well described by an exponential form, we demonstrate that these fits do not provide reliable estimates of the critical packing fraction, $ \phi_0$ , owing to the substantial extrapolation required beyond the accessible equilibrium range. We find the commonly assumed proportionality between $ \eta$ and the structural relaxation time, $ \tau_\alpha$ , to not hold for this system. For $ \phi\gtrsim 0.570$ , the van Hove self-correlation function $ G_s(r, \tau)$ exhibits a spatial exponential decay at intermediate times, $ \tau$ , signaling dynamic heterogeneity. The characteristic decay length scales as $ \lambda \sim \tau^\nu$ , with $ \nu \approx 1/3$ , in contrast to the conventional square-root scaling. We also investigate temporal heterogeneity through the four-point dynamic susceptibility, $ \chi_4(\tau)$ , and its peak time, $ \tau_4$ . These findings provide rigorous benchmark MD data for computational studies of glassy dynamics and establish a reference for testing theoretical models in dense disordered systems.
Soft Condensed Matter (cond-mat.soft), Other Condensed Matter (cond-mat.other)
Curvature-Induced Geometric Universality in Non-Hermitian Anderson Transitions
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-09-10 20:00 EDT
Chen Wang, Run-Qiu Yang, X. R. Wang, Hechen Ren
In Euclidean space, universality classes of Anderson transitions are primarily determined by symmetry and spatial dimensionality. Here, we present evidence for a geometry-controlled universality class of non-Hermitian Anderson transitions on hyperbolic-like lattices. In this setting, critical behavior is influenced by the large-scale hyperbolic geometry, characterized by negative curvature, exponential volume growth, and a non-Euclidean notion of spatial scaling. Finite-size scaling of participation ratios across several distinct ( {p,q} ) tilings reveals one-parameter scaling collapses with a common critical exponent ( \nu\simeq1 ) within numerical accuracy. A complementary phenomenological coarse-grained Landau-Ginzburg analysis shows how exponential correlation-volume growth suppresses critical fluctuations, offering a rationale for the observed mean-field-like scaling. Our results suggest that spatial curvature can act as an additional organizing principle for Anderson-transition universality beyond the conventional dimensionality- and symmetry-based classification.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
6 pages, 3 figures
Composition and Surface Termination Control Band Alignments in P3HT/Perovskite Heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Somayyeh Alidoust, V. Ongun Özçelik
Hybrid organic-inorganic perovskite heterostructures are emerging platforms for energy conversion and optoelectronic devices, yet the effects of composition and surface terminations on band alignment remain poorly understood. Here, using high-throughput first-principles calculations, we systematically reveal the effect of composition and surface termination on the band alignment of 820 heterostructures formed between poly(3-hexylthiophene) (P3HT) variants and conventional and mixed-cation metal halide perovskites. Band edge analysis predicts concentration dependent band alignments, with most Pb and Sn based perovskites exhibiting Type II and III behavior while mixed-cation CsMASnBr3 uniquely forms Type-I junctions with all P3HT variants. Explicit interface calculations reveal that surface termination can reverse the predicted alignment in conventional tin perovskites, while the mixed cation perovskite preserves Type-I alignment with P3HT regardless of termination. Despite negligible charge transfer, termination dependent band offsets produce markedly different carrier confinement, establishing design principles for engineering P3HT/perovskite interfaces.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
The validity of the Stokes-Einstein relation in ionic liquids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
Ionic liquids (ILs) exhibit supercooled liquids behavior even above room temperature and the Stokes-Einstein (SE) relation is often considered to be invalid in ILs as that in supercooled liquids. However, the conclusion is usually drawn based on some variants of SE relation. In this work, we have systematically investigated the validity of the Stokes-Einstein relation in ILs by performing molecular dynamics simulations of coarse-grained IL within the temperature range of 400-800 K. Both the original SE formulation, and two commonly employed variants, were examined to assess their applicability and consistency. These three formulas yield distinctly different results, indicating that the two variants are not reliable substitutes for the original SE relation. The inconsistency suggests the fact that the r in Stokes law varies with conditions. The breakdown arises from the ion correlations introduced by the strong electrostatic interactions. This proposition is further confirmed by simulations.
Soft Condensed Matter (cond-mat.soft)
The effect of Coulomb interactions of thermoelectric characteristics of Marcus molecular junctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
We present a theoretical study focused on the influence of Coulomb interactions on thermoelectric properties of molecular junctions assuming that electron transport is strongly affected by thermalized phonon modes in the molecular ambient. It is shown that the combined effect of Coulomb interactions between electrons on the molecular states and the reorganization processes in the ambient may significantly affect both Seebeck coefficient and the power factor. Specifically, we show that electron-electron interactions may counter-balance the effect of the ambient molecules reorganizations resulting in qualitative changes in the behavior of both zero-bias conductance and thermopower.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
6 pages, 4 figures,
Energy Transport Structure and Fluctuation Theorem in Nonreciprocal Harmonic Chains
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Ziwei Cheng, Geng Li, Zhanchun Tu
Nonreciprocal interactions fundamentally alter energy transport by breaking the symmetry between forward and backward responses. Here, we uncover an exact transport structure for a one-dimensional harmonic chain with asymmetric nearest-neighbor couplings. Using a Green-function approach, we demonstrate that the direction of heat transport is determined not solely by the temperature bias, but by its competition with an effective directional asymmetry. This competition can reverse the direction of heat flow, enabling cold-to-hot transport. We further show that nonreciprocity introduces an additional power channel associated with the antisymmetric sector of the interaction, leading to a generalized steady-state energy balance involving two reservoir heat currents and a nonreciprocal power current. At the fluctuation level, the heat exchanges with the two reservoirs constitute correlated yet distinct stochastic currents, whose joint scaled cumulant generating function obeys an exact Gallavotti-Cohen symmetry. Together, these results establish a unified energetic and fluctuation framework for nonreciprocal heat transport and demonstrate that directional interactions can serve as an active resource for controlling nonequilibrium energy flows.
Statistical Mechanics (cond-mat.stat-mech)
Coarse-graining to create minimalist models for dynamic, end-linked star-polymer networks
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
Tyla R. Holoman, C. Levi Petix, Michael P. Howard, Thomas M. Truskett
Although minimalist models for patchy attractive particles have revealed powerful design rules for how particle valence directs colloidal assembly, less work has focused on comparably simple models of reversible, network-forming star polymers. Here, we use relative-entropy coarse-graining and simulation results from finer-resolution bead–spring star polymers to generate 5-bead models of dynamic, end-associating four-armed poly(ethylene glycol) macromers. Our results comparing structural correlations, network connectivity, and phase behavior of the coarse- and fine-grained models provide insight into how the accuracy and transferability of the coarse-grained models depend on the state point chosen for coarse-graining. The results also reveal intrinsic trade-offs between reducing degrees of freedom and expanding the range of effective interactions in coarse-graining that impact the total number of pairwise interactions in the resulting model, with implications for its computational efficiency.
Soft Condensed Matter (cond-mat.soft), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
25 pages, 7 figures, 1 table
An encoded asymmetric ligand for metal-selective topological assembly of two-dimensional metal-organic frameworks
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Huimin Qi, Jinkun Guo, Xinyan Wu, Weishan Li, Tongyang Zhao, Ze-Fan Yao, Hao Chen, Ling Zhang, Bin Jiang, Yi Liu, Haoyang Zhang, Yunlong Fan, Tianyang Chen, Qingqing Ji, Jin-Hu Dou
Two-dimensional metal-organic frameworks (2D MOFs), with diverse topological architectures, provide a powerful platform for exploring unconventional electronic and lattice-dynamical responses. Yet their structural diversity remains fundamentally constrained by the fixed geometry of high-symmetry ligands. Here, we introduce an encoded asymmetric ligand, benzo[b]triphenylene-2,3,6,7,11,12-hexaol (BTH), for metal-selective topological assembly. By integrating multi-site coordination fields with sterically differentiated environments, BTH exhibits distinct topological programmability: different divalent metal ions direct divergent framework architectures. Specifically, coordination of BTH with divalent Cu(II) and Zn(II) ions assembles Cu-BTH-MOF with a dual-mode hexagonal pore topology and Zn-BTH-MOF with uniform hexagonal channels, respectively, as supported by PXRD Pawley refinement, structural simulations, and pore-size distribution analysis. Furthermore, this topological divergence is accompanied by a significant divergence in charge-transport properties, with Cu-BTH-MOF reaching an electrical conductivity of 1.186 x 10-3 S cm-1, more than six orders of magnitude higher than that of Zn-BTH-MOF (3.38 x 10-10 S cm-1). This work establishes ligand desymmetrization as a programmable strategy for metal-selective topological diversification in 2D MOFs.
Materials Science (cond-mat.mtrl-sci)
Heteroepitaxial Growth of PbSe on InP Substrates via Lattice-Matched III-V Buffer Layers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Biridiana Rodriguez, Mark Martino, Brody Yeung, Benjamin Sprenger, Leland Nordin
Detector cost remains a barrier to the widespread adoption of mid-wave infrared (3-5 micron) technology. PbSe, an inexpensive narrow band gap IV-VI semiconductor that has been used since the early 1940s, delivers high performance for infrared detection despite the abundance of grain boundaries in polycrystalline films. Epitaxial growth, however, could provide superior crystalline quality and interfaces, but suitable substrates remain limited for PbSe. Recent PbSe heteroepitaxy has focused primarily on III-V, II-VI and group-IV substrates that each offer a comparatively narrow range of lattice-matched alloys for heterostructure engineering. Here we show that InP-based heteroepitaxy provides access to a broader materials platform while limiting the lattice mismatch with PbSe to approximately 4%. We grow 150-nm thick PbSe films by molecular beam epitaxy on 200-nm thick In0.53Ga0.47As and In0.52Al0.48As buffers on (001) InP substrates. Reflection high-energy electron diffraction and X-ray diffraction show (001)-oriented rock-salt PbSe with an out-of-plane lattice constant of 6.12 Angstrom on both buffers. Photoluminescence (PL) is observed from room-temperature down to 12 K and the peak wavelength red-shifts from 3.7 to 5.0 microns. Under identical measurement conditions, the room-temperature peak PL intensities from films on In0.53Ga0.47As and In0.52Al0.48As are approximately 1.9x and 1.3x that of a PbSe on GaAs substrate reference, respectively. These results establish an InP-compatible platform for integrating narrow band-gap PbSe with a broad range of ternary and quaternary III-V alloys, including, for example, structures in which In0.53Ga0.47As serves as both a short-wave infrared absorber and a template for PbSe growth.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Optics (physics.optics)
Twist and strain identification in moiré heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Zhen Zhan, Federico Escudero, Dong Wang, Yiwen Liu, Ambikesh Gupta, Pierre A. Pantaleón, Francisco Guinea
The geometrical and electronic properties of moiré materials are highly sensitive to the twist and strain in the samples due to the moiré magnifying effect. Accurate identification of twist and strain in moiré materials is therefore essential. In this work, we establish a general framework to extract the twist and strain configurations from moiré images with either atomic or moiré scale resolution. With only moiré-wavelength information, we show that there is a continuous family of possible twist and strain configurations, each one accounting for different orientations of the moiré pattern. To estimate the most likely twist-strain configuration, we discuss additional constraints and methods involving the minimum elastic energy and the electronic spectra. The minimum elastic energy, in particular, reflects that shear configurations become much more favorable as the strain increases. As an example of the developed methodology, we discuss the formation and identification of strained triangular moiré patterns. Our framework provides a comprehensive approach to identify the twist and strain configurations in systems with moiré-scale resolution.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
15 pages, 5 figures. Comments are welcome!
Eight-unit-cell electronic modulations in cuprates originating from local molecular orbitals
New Submission | Superconductivity (cond-mat.supr-con) | 2026-09-10 20:00 EDT
Zhiheng Yao, Sixuan Chen, Jianfa Zhao, Shusen Ye, Weixiang Qu, Ning Xia, Yuling Dai, Luchuan Shi, Hongrui Zhang, Zhenqi Hao, Changqing Jin, Shuo Yang, Yayu Wang
The pair density wave (PDW) state with eight-unit-cell (8a0) periodicity has been widely regarded as the primary order in cuprates, yet its existence and origin remain subjects of intense debate. Using spectroscopic imaging scanning tunneling microscopy, we observe spatial modulations of the electronic states with approximately 8a0 periodicity in both the superconducting and insulating regimes of hole-doped Ca2CuO2Cl2 cuprate. We find that the 8a0 spatial patterns are generated by the formation of molecular orbitals by doped holes, which organize into 4a0\ast4a0 plaquettes as the basic unit. Our results identify the 4a0 molecular orbital as the fundamental electronic building block in cuprates, while the 8a0 PDW represents a spatial subharmonic that emerges at sufficiently high doping.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
to appear in PRL
Renewal process’s guide to fractional Navier-Stokes equations
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
The Navier-Stokes equations, which remain unsolved, are crucial equations in fluid mechanics. Discovering the solutions to the Navier-Stokes equations is one of the challenging Millennium problems. In 1900, Hilbert proposed a potential approach to tackle this problem by establishing the relationship between microscopic dynamics and the macroscopic continuum equations. The key bridge is the derivation of Boltzmann equation and the theory of probability. In this paper, we shall use the collision renewal process with arbitrarily distributed waiting times to derive the Boltzmann equation for the time evolution of the probability of the velocity and the displacement of the particle, based on which we prove that the renewal process with exponential collision waiting time is equivalent to the classical Navier-Stokes equations, and that with power-law waiting time is equivalent to the fractional Navier-Stokes equations. Since the collision renewal process with arbitrarily distributed waiting times is a random process and is easy to perform the stochastic simulations of trajectories to obtain the corresponding solution, we actually find a stochastic approach to solve the classical and fractional Navier-Stokes equations.
Statistical Mechanics (cond-mat.stat-mech)
Geodesic Trapping and Escape of Active Particles on Curved Surfaces
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
Yuzhu Chen, Vishal P. Patil, David Saintillan
Active particles on curved surfaces can become trapped along closed geodesics even without physical barriers. We show that escape from these geometric traps exposes a fundamental distinction between continuous and discrete reorientation. At high Péclet numbers, active Brownian particles escape efficiently through rotational diffusion, whereas run-and-tumble particles remain trapped much longer; at low Péclet numbers, both reduce to passive diffusion. Gaussian curvature controls escape by focusing or defocusing neighboring geodesics, producing distinct asymptotic scalings of the mean exit time.
Soft Condensed Matter (cond-mat.soft)
main text 6 pages, 4 figures
Microscopic Understanding of Thermal-magnon Transport in a Low-damping Ferrimagnetic Thin Films
New Submission | Other Condensed Matter (cond-mat.other) | 2026-09-10 20:00 EDT
Lerato Takana, Katya Mikhailova, Junwei Tong, Xiangcheng Liu, Kwangyul Hu, Juan Hofer, Guanxiong Qu, Clare Yu, Ivan Schuller, Michael Flatté, Xiaoqin Li, Yuri Suzuki
Thermally generated magnons enable heat-driven spin transport in magnetic insulators, yet the microscopic mechanisms governing their propagation remain poorly understood. Here, we investigate thermal magnon transport in low-damping Li$ _{0.5}$ Al$ _{1.0}$ Fe$ _{1.5}$ O$ _4$ /Pt nanodevices using a nonlocal spin Seebeck geometry that separates magnon transport from local thermoelectric effects. Thermal imaging establishes a detector region outside the thermal healing length, enabling intrinsic nonlocal measurements. We find that thermal magnon transport is strongly suppressed by magnetic fields far above saturation. Brillouin light scattering reveals that increasing field reduces the group velocity of backward volume magnons, providing a microscopic origin for the observed reduction in magnon spin diffusion length. We further find that thermal magnon transport decreases with increasing temperature despite an increasing magnon population. Micromagnetic simulations reproduce this behavior only when a temperature-dependent exchange stiffness is included. These results identify magnon group velocity and exchange stiffness as key parameters governing thermal magnon transport in ferrimagnetic thin films.
Other Condensed Matter (cond-mat.other)
Automated Generation of Commensurate Magnetic Structures based on Spin Space Groups and Graph Theory
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Yifan Wang, Boyang Deng, John Robertson, Weisheng Zhao, Stefan Blügel, Haichang Lu
Magnetic structures with symmetry constraints are candidates for energetically favorable configurations. Enumerating these structures is essential for identifying experimental observations and provides unbiased, linearly stable, and optimally sampled reference configurations for energy fitting when extracting spin interactions. We present SpinGraph, an automated workflow generating symmetry-distinct magnetic configurations. SpinGraph is not only compatible with the more general spin space groups, but also allows precise control of the prescribed single- or multi-Q states superposition. For finite groups, we enumerate compatible subgroups directly. For spin space groups with a continuous or special spin-only part, the finite component is enumerated first and then combined with the compatible exact spin-only constraints. These actions are translated into graph constraints in real or Fourier space. The symmetry of every generated structure is re-evaluated after construction. Finally, we integrate SpinGraph with the magnetic analysis code AMATIS to perform a thorough calculation for the spin interactions of the insulating monolayer CrI3. SpinGraph complements the last part of AMATIS and realizes the fully automated workflow for the spin Hamiltonian construction, which is essential for studying phase transitions, spin textures, magnons, and spin dynamics.
Materials Science (cond-mat.mtrl-sci)
14 pages, 2 figures, supplementary will be in the published journal
Anomalous Hall Response Induced by Correlated Disorder in the Breathing Kagome Lattice Mn$_{3}$Sn
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Tsung-Han Yang, Seng Huat Lee, Hengxin Tan, Yuanpeng Zhang, Benjamin A. Frandsen, Václav Petříček, Huibo Cao, Daniel Olds, Matthew G. Tucker, Jiaqiang Yan, Binghai Yan, Zhiqiang Mao, Qiang Zhang
Macroscopic transport tensors are generally constrained by the average crystallographic and magnetic symmetries of a material. In the kagome antiferromagnetic Weyl semimetals Mn$ {3+\delta}X$ ($ X=$ ~Sn or Ge), previous studies showed that the anomalous Hall conductivity $ \sigma{yx}$ is forbidden by the average \hexsg{} structure and coplanar inverse-triangular magnetic order. Here we report that nearly stoichiometric Mn$ 3$ Sn nevertheless exhibits a finite $ \sigma{yx}$ with large hysteresis, together with enhanced $ \sigma_{zx}$ and $ \sigma_{yz}$ , in the inverse-triangular phase below $ T_{\mathrm{N1}}\approx 440\mathrm{K}$ , whereas all AHE components vanish in the amplitude-modulated conical phase below $ T_{\mathrm{N2}}\approx 280\mathrm{K}$ . Total scattering and magnetic pair distribution function analysis reveal correlated orthorhombic distortions and noncoplanar Mn moments. First-principles calculations show that this coupled lattice-spin distortion activates the average symmetry forbidden $ \sigma_{yx}$ within the inverse-triangular phase. Its disappearance below $ T_{\mathrm{N2}}$ indicates that the correlated disorder must cooperate with a long-range inverse-triangular antiferromagnetic order capable of supporting Berry curvature. Our results establish correlated disorder as an active symmetry-breaking degree of freedom that enables topological transport inaccessible from the Bragg-average structure alone.
Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 7 figures, plus one Supplemental Material
First-principles investigation of structural, mechanical, vibrational, thermal, electronic and optical properties of Na3Bi: a topological Dirac semimetal
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Maisha Fahmida, Syed Shovon Mahbub Mahin, Suptajoy Barua, Ishtiaque M. Syed
Exploring the properties of topological materials has remained an active area of research in condensed matter physics for the past few decades. Here, we present a first-principles investigation of the structural, elasto-mechanical, thermal, electronic, and optical properties of Na3Bi, one of the earliest discovered topological Dirac semimetals, using density functional theory. The hexagonal phase of Na3Bi is found to be both mechanically and dynamically stable, exhibiting moderate elastic anisotropy with a universal anisotropy index of 0.832. The compound displays a moderate machinability index of 2.386 alongside a low hardness value of 2.005, consistent with its predominantly brittle, covalently bonded character accompanied by a slight metallic contribution. Its comparatively low Debye temperature of 181.39K points to a mechanically soft lattice with loosely bound atoms. Electronic structure calculations confirm semimetallic behavior, with well-defined Dirac points pinned at the Fermi level and a Fermi surface composed of point-like pockets. Optical analysis across a wide spectral range reveals non-selective, moderate reflectivity of 40 to 45% and, in the visible region, an unusually high refractive index reaching between 2 and 4.5. Na3Bi is additionally found to be an efficient absorber of ultraviolet radiation. Together, these findings establish a comprehensive baseline for the mechanical, thermal, and optical behavior of hexagonal Na3Bi and point to its potential relevance for acoustic damping, UV-sensing, and optoelectronic applications
Materials Science (cond-mat.mtrl-sci)
A discrete Stiefel-Whitney invariant with twofold rotation symmetry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
We review Stiefel–Whitney invariants and give a discrete formulation of an additional $ \mathbb{Z}2$ invariant for two-dimensional spinful insulators with twofold rotation and time-reversal symmetries (layer group $ p1121’$ ). A singular gauge transformation specifies a real bundle over the quotient of the Brillouin torus, whose second Stiefel–Whitney number defines the invariant. We derive its dependence on the choice of auxiliary gauge function and prove invariance under changes of Bloch frame and additivity under direct sums. The discrete formula uses overlaps of independently chosen Bloch frames and symmetry-compatible $ \mathrm{Pin}+$ lifts on the boundary of a half Brillouin zone. Atomic and topological-insulator models illustrate the formula and distinguish the additional invariant from the Kane–Mele index. Together with three quantized $ \mathbb{Z}_2$ partial polarizations and the filling number, it labels the known stable classification $ \mathbb{Z}\oplus\mathbb{Z}_2^{\oplus 4}$ .
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
24 pages
Record-Breaking Elemental Superconductivity in Tetralayer Kagome Borophene
New Submission | Superconductivity (cond-mat.supr-con) | 2026-09-10 20:00 EDT
Yingnan Liu, Yan Liu, Renyu Duan, Menghui Wang, Meiling Xu, Hanyu Liu, Shoutao Zhang
Superconductivity above the liquid-nitrogen temperature remains rare in two-dimensional elemental crystals, where strong covalent bonding often yields high phonon frequencies but insufficient electron-phonon coupling. Here, using first-principles calculations and fully anisotropic Migdal-Eliashberg theory, we predict tetralayer kagome borophene (TKB) stabilized by ABAB covalent stacking, as a liquid-nitrogen-temperature elemental superconductor. With a predicted critical temperature of 102 K, TKB sets a record-high value among previously reported elemental superconductors. Unlike known high-Tc boron-based superconductors dominated by in-plane sigma-bonding states and high-frequency in-plane B-B stretching modes, TKB realizes an out-of-plane s-pz-bonding-mediated pairing mechanism, in which interlayer s-pz bonding states at the Fermi level are strongly coupled to low-frequency out-of-plane vibrations of boron atoms. These results reveal a distinct out-of-plane pairing channel in multilayer borophene and establish covalent stacking engineering as a potential route for high-Tc superconductivity in two-dimensional materials.
Superconductivity (cond-mat.supr-con)
6 pages, 3 figures
Fractional Chern Insulators in Twisted Bilayer Optical Lattices
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-09-10 20:00 EDT
Yan-Bin Yang, Jiong-Hao Wang, Shicheng Ma, Yong Xu
Twisted bilayer materials provide a versatile platform for realizing novel topological states. Motivated by recent experimental realization of atomic Bose-Einstein condensates in twisted bilayer optical lattices, we theoretically investigate topological states for cold atoms trapped in such a system. At single-particle level, the system hosts nearly flat moiré bands under appropriate experimental parameters. Although these noninteracting bands are topologically trivial in the Altland-Zirnbauer classification, we find that atomic interactions can induce a flat Chern band based on self-consistent Hartree-Fock calculations. Furthermore, exact diagonalization identifies a fractional Chern insulator phase at fractional filling. Our work thus paves the way for exploring strongly correlated topological phases in highly tunable twisted bilayer optical lattices.
Quantum Gases (cond-mat.quant-gas)
10 pages, 4 figures
Intermittent continuous-time random walks under renewal reset mechanism
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Guohua Li, Hong Zhang, Yuexiong Liu
Stochastic resetting as a practical and efficient search strategy in complex and disordered environments has long been a topic of interest to researchers. Based on the competition between jumping and resetting, this article proposes and investigates intermittent continuous-time random walks (CTRWs) under stochastic resetting, using the smaller waiting time for jump and reset as the renewal time, where the waiting times for both jump and reset can have arbitrary distributions. After each renewal event, the system will proceed with new waiting times for jump and reset regardless of their previous histories. We study the governing equation and Montroll-Weiss equation with renewal resetting, as well as the Markovian resetting for intermittent CTRWs. We prove the existence of non-equilibrium stationary states within the renewal reset mechanism when the jump and reset waiting times follow any exponential and power law distributions. For exponential and Gaussian distributed jump lengths, we examine the mean square displacements (MSDs) of particles to determine their monotonicity and asymptotic stability. Moreover, we calculate the first-arrival time to quantify search efficiency, and validate the intermittent CTRWs under renewal resetting lead to a finite mean first-arrival time (MFAT) to any fixed position for exponential jump and reset waiting time distributions (WTDs), power-law jump and exponential reset WTDs, as well as exponential jump and power-law reset WTDs. However, the MFAT diverges for power-law jump and reset WTDs. The intermittent CTRW model, which is based on the competition mechanism, can be applied to many physical scenarios, such as the foraging strategy of animals that return to their nests after an unsuccessful foraging attempt, or the work planning of intelligent robots that return to energy replenishment points after prolonged operation.
Statistical Mechanics (cond-mat.stat-mech)
Orbital-selective electronic modes induced by doping and originating from distinct spin excitations: an essential feature of orbital-selective Mott transition
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
The nature of the orbital-selective Mott transition (OSMT) remains elusive. This study shows that, by doping an orbitally degenerate spin-1 antiferromagnetic insulator in the Kanamori-Hubbard model, electronic modes emerge in the band gap in an orbital-selective manner, exhibiting momentum-shifted spin-mode dispersion relations. Electronic modes originating from conventional spin excitations, including the low-energy one, appear in the doped orbital, while those from inter-orbital spin excitations appear in the undoped orbital. These emergent modes constitute an essential feature of the OSMT.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech), Superconductivity (cond-mat.supr-con)
5 pages, 3 figures
Morphology and depletion force-based large-scale self-assembly of nanocubes on surface
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Yeonhee Lee, Seungsang Cha, Yuna Kwak, Nicholas Juntunen, Grant M. Rotskoff, Jwa-Min Nam
Self-assembling nanoparticles is a highly efficient and facile way to form functional nano-, micro- and macrostructures. However, currently available methods lack precision and controllability in size, shape and composition, suffer from poor reproducibility and scalability, and require complex steps and expensive materials. Here, we present the uniform morphology-induced and depletion force-directed nanoparticle assembly on surface (MIDAS) method with gold nanocubes (AuNCs). Using this approach, morphology-sensitive depletion forces trigger shape-selective flocculation and assembly of the AuNCs with uniform size and shape. Importantly, the surface roughness-controlled substrate drives the large-scale formation of AuNC-assembled monolayers (2D AuNAMs) or three-dimensional AuNC-assembled multilayers (3D AuNAMs) in a highly specific manner without any complex ligand modification or preparation steps. Lattice-gas modeling and kinetic Monte Carlo simulations show the depletion force is the key parameter determining supercrystal morphology and corroborate the experimental findings. This work establishes a generalizable nanoparticle assembly mechanism and demonstrates the broad applicability of the MIDAS strategy for scalable fabrication and patterning of 2D and 3D nanoparticle architectures.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
25 pages, 6 figures
Facile hBN-hBN Interfacial Overlap Engineering for Enhanced Quantum Emitter Formation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Nhat Minh Nguyen, Trung Vuong Doan, Md Shakhawath Hossain, Akila Elangasinghe, Duc Anh Ngo, Ha Ngoc Duy Huynh, Thi Ngoc Anh Mai, Yongliang Chen, Kenji Watanabe, Takashi Taniguchi, Michael G. Ruppert, Chaohao Chen, Xiaoxue Xu, Toan Dinh, Toan Trong Tran
Quantum emitters in two-dimensional materials, particularly hBN, are promising platforms for quantum technologies. However, achieving high-density emitters at predetermined locations while preserving optical quality remains challenging. Here, we introduce a facile, cost-effective double-layer all-dry transfer approach to deterministically create overlap regions between hBN flakes. These pre-defined capped regions exhibit a significantly enhanced emitter density, with up to a 15-fold increase compared to uncapped areas. Importantly, this method does not compromise emitter quality: emitters within overlap regions demonstrate excellent optical performance, including high signal-to-background and signal-to-noise ratios, large Debye-Waller factors, high brightness, and strong spectral stability. Possible defect configurations are also discussed to contextualize the observed emission characteristics. This scalable strategy enables preferential formation of quantum emitters in targeted regions, achieving higher densities than simple treatments such as plasma irradiation while avoiding the complexity of advanced fabrication techniques. The approach provides a practical pathway for integrating high-quality quantum emitters into scalable quantum photonic platforms.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Semi-Dirac States and Quantum Linear Magnetoresistance in Helimagnetic Pnictide MnP
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Prasanta Chowdhury, Jyotirmoy Sau, Sanat Kumar Adhikari, Sourav Chowdhury, Peter Bencok, Matthias Gutmann, Souvik Chatterjee, Saurav Giri, Manoranjan Kumar, Subham Majumdar
Large linear positive magnetoresistance (LPMR) in topological and magnetic materials remains a subject of intense debate, particularly in noncollinear spin systems where spin-dependent scattering complicates charge transport. Manganese phosphide (MnP), a helimagnetic binary pnictide with multiple field-induced magnetic transitions, provides a useful platform to investigate the interplay between complex magnetism and electronic topology. Here, we present a comprehensive experimental and theoretical investigation of phase-dependent magnetotransport in high-quality MnP single crystals. Hall measurements reveal an anomalous Hall effect dominated by skew scattering at high temperatures and a finite topological Hall effect in the noncollinear fan (FAN) and low-temperature screw (SCR) phases. At low temperatures, we observe a large, non-saturating LPMR reaching nearly 800 percent at 4 K and 15 T, with a pronounced linear field dependence in the field-polarized ferromagnetic (FM2) state. First-principles calculations reveal a strongly anisotropic semi-Dirac-like band at the Y point that progressively approaches the Fermi level from the SCR to FAN and FM2 states. Our analysis indicates that the resulting small Fermi pocket can access the extreme quantum-limit regime at experimentally accessible fields, providing a microscopic framework for the observed LPMR within Abrikosov’s quantum magnetoresistance theory.
Strongly Correlated Electrons (cond-mat.str-el)
15 pages, 9 figures
uFlowCSP: Crystal Structure Prediction using Mean flow generative models
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Sourin Dey, Dipannoy Das Gupta, Lai Wei, Sadman Sadeed Omee, Jianjun Hu
Crystal structure prediction (CSP) is fundamental to computational materials discovery. Generative models including CDVAE, DiffCSP, FlowMM, and CrystalFlow learn stable-crystal distributions directly, but diffusion and flow-matching inference requires tens to thousands of sequential network evaluations per candidate.
We introduce uFlowCSP, a MeanFlow-based CSP model that learns the average, rather than instantaneous, probability-flow velocity. It generates a complete structure in one to five evaluations, delivering 5x-58x faster inference with equal or better performance. A chemistry- and symmetry-aware Transformer uses canonical atom ordering, global composition, and per-token chemistry embeddings. A coarse crystal-system token is used only during training; it provides additive gains, particularly improving space-group agreement despite being absent at inference, which remains formula-only.
On MP-20 with 20 candidates per target, one step matches CrystalFlow (78.38% vs. 78.34%) with 100x fewer evaluations and about 10x lower wall-clock time. Five steps reach 83.64%, exceeding CrystalFlow (78.34% at 2,000 evaluations) and DiffCSP (77.93% at about 20,000), while using 20x fewer evaluations. uFlowCSP generates 10,000 structures in 0.39-1.31 minutes, versus 6.5 for CrystalFlow and 76.1 for DiffCSP. Under CSPBench’s energy-ranked top-five structure-and-space-group criterion, five-step uFlowCSP reaches 72%/72%/65% structure, space-group, and consensus match rates. CrystalFlow reaches 78%/73%/68% at 100 steps but falls to 49%/32%/31% at five. Thus, uFlowCSP improves accuracy per network evaluation, not merely peak accuracy.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI), Machine Learning (cs.LG)
Photo-induced Wavelength-tuning of Telecom-band Quantum Dot Nanowires Embedded in a Phase Change Material
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Evangelos Sotiropoulos, Philippe Regreny, Matthieu Bugnet, Nicholas P. Blanchard, Sébastien Cueff, José Penuelas, Nicolas Chauvin
Scalable quantum-photonic technologies require spatially separated emitters to emit at the same wavelength, yet epitaxially grown quantum dots naturally exhibit emitter-to-emitter variations in their emission energies. Here, we demonstrate a contact-free post-growth tuning approach for InAs quantum dots embedded in InP nanowires using the photo-induced transformation of an amorphous Sb2S3 shell. This photoinduced effect leads to a progressive relaxation of the strain imposed on the InP core, enabling controlled spectral tuning of the quantum-dot emission. The effect is observed both at room temperature and under cryogenic conditions for quantum dots emitting in the O-band of the telecommunications spectrum. Strain-induced redshifts of approximately 7 meV at room temperature and 28 meV under cryogenic conditions are observed, respectively. The use of an amorphous chalcogenide shell therefore provides a route to achieve local wavelength tuning at the single quantum-dot-in-a-nanowire level after growth. This approach could enable spectrally matched emitters for scalable quantum-photonic architectures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Quantifying cell shape and density fluctuations in epithelial tissue in vivo
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Jake Turley, Helen Weavers, Paul Martin, Isaac V. Chenchiah, Tanniemola B. Liverpool
Controlling changes in cell shape are crucial for many biological processes, such as tissue development and wound healing. Tissues typically are heterogeneous with a variety of cell shapes and sizes. Of particular interest are local deviations from an average cell shape and size. These fluctuations may extend and transmit across tissues, potentially offering valuable insights into tissue characteristics such as variations in effective “stiffness” or rigidity. In this study, we present a theoretical framework that captures the dynamics of epithelial cell shapes within tissue, incorporating both their average behaviour and fluctuation patterns. We model cells as interacting soft ellipsoids of varying size and aspect ratio. Coarse-graining our model, we obtain a set of continuum stochastic differential equations from which we derive spatial-temporal correlation functions. These correlation functions fit with our experimental data from the developmental process of the \textit{Drosophila} pupal wing. From the correlation functions, critical parameters representing active cell shape changes and effective tissue “stiffness” can be determined.
Statistical Mechanics (cond-mat.stat-mech)
Apparent Zero-Momentum Signals from Magnon–Magnon Interference in Near-Field Spin-Wave Imaging
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Julien Berthomier, Romain Lebrun, Vincent Cros, Jamal Ben Youssef, Karim Bouzehouane, Abdelmadjid Anane
Spatially resolved measurements of coherent waves are commonly read as direct maps of the underlying eigenmode spectrum. We show that this interpretation fails in near-field imaging of multimode spin-wave transport. Scanning nitrogen-vacancy magnetometry of yttrium iron garnet reveals pronounced apparent low-wave-vector signals at frequencies for which no propagating spin-wave mode exists. By tuning the probe-sample distance and modeling the anisotropic near-field response, we identify their origin as coherent mixing between directly excited Damon-Eshbach waves and defect- or transducer-scattered spin waves: the measured signal acquires spatial Fourier components at the difference wave vector $ \mathbf{k}{\mathrm{exc}}-\mathbf{k}{\mathrm{scat}}$ , which can vanish even though both constituent waves carry finite momentum. These results establish that near-field spectra of coherent excitations are interferometric field spectra rather than eigenmode maps, providing both a caution and a framework for identifying scattering processes in nanoscale magnonic devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Dimensional Control of Excitonic Interactions in Exfoliated 2D Molecular Crystals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Jonghyun Son, Seonghyun Koo, Daniel Yim, Sangjin Han, Dong-Hwan Yang, Gi-Yeop Kim, Kihyun Lee, Jieun Yeon, Hye Soo Kim, Eunbeen Jeon, Minji Ko, Minhee Choe, Kenji Watanabe, Takashi Taniguchi, Hee Cheul Choi, Kwanpyo Kim, Si-Young Choi, Seogjoo J. Jang, Hyungjun Kim, Sunmin Ryu
Two-dimensional (2D) materials provide unique opportunities to tailor excited-state properties through reduced dimensionality, altered dielectric screening and layer-dependent structural reconstruction. While such effects have been widely explored in norganic systems, their realization in molecular crystals has been limited by the difficulty of controlling thickness at the atomic scale while preserving crystalline order. Here we show that tetracene and three other molecular crystals can be mechanically exfoliated into mono-, few- or multilayer flakes, while retaining crystalline order. This capability enables new studies of molecular crystals across a well defined thickness range within the same structural organization. Thickness-dependent spectra of these samples reveal how out-of-plane confinement modifies the excited-state energy landscape of tetracene: With decreasing thickness, the Davydov splitting diminishes, the Stokes shift increases, and signatures of more delocalized excitons emerge. Electron diffraction and exciton model-based analyses correlate these trends to changes in molecular packing, intermolecular coupling and dielectric screening. Our results also demonstrate that key features of molecular excitons can be systematically tuned by layer number, extending dimensional control from inorganic 2D materials to molecular crystals.
Materials Science (cond-mat.mtrl-sci)
Configurational-space separation and structure selection in three hard squares
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
Yuheng Yang, Meng Xiao, Duanduan Wan
Self-assembly of hard particles with diverse shapes gives rise to a rich variety of structures through excluded-volume constraints alone. Here we show that even a minimal system of three hard squares confined in a two-dimensional periodic box exhibits nontrivial configurational behavior relevant to structure selection. As the packing fraction increases, radial distribution functions obtained from Markov-chain Monte Carlo and uniform non-overlapping insertion sampling agree at low densities, deviate markedly over an intermediate range, and converge again at higher densities. Pressure measurements provide strong numerical evidence that the discrepancy originates from the separation of the allowed configurational space into two disconnected regions above a characteristic density. We identify the separation density as $ \phi_{\rm sep}=3/5$ , construct explicit overlap-free transition pathways connecting the two regions immediately below it, and quantify their relative configurational-space volumes. At higher packing fractions, an approximately L-shaped arrangement of the particle centers becomes strongly favored over a staggered one, revealing a structural motif characteristic of tetratic and square-lattice ordering in larger hard-square systems. These results show that excluded-volume geometry can govern both configurational connectivity and local structure selection even in a three-particle system, revealing how signatures of many-particle self-assembly can already emerge in the few-particle limit.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
6 pages, 4 figures and Supplemental Material
Strong Impact of Halide Ordering on Structural Phase Transitions in Mixed Perovskites
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Felix Uddén, Erik Fransson, Julia Wiktor, Benjamin M. Gallant, Dominik J. Kubicki, Paul Erhart
Mixed halide perovskites are highly versatile semiconductors with applications in photovoltaics, light-emitting diodes, and photodetectors. Understanding their thermodynamic phase behavior is central to guiding compositional design and improving device stability. Here, we train machine-learned interatomic potentials (MLIPs) on density functional theory reference data for CsxRb1-xPbBr3yI3-3y, CsxRb1-xPbBr3yCl3-3y, and CsxRb1-xPbCl3yI3-3y halide perovskites, enabling large-scale hybrid Monte Carlo-molecular dynamics simulations that sample both configurational and vibrational degrees of freedom. All three binary halide systems exhibit a miscibility gap, the extent of which correlates with halide ion size mismatch. The gaps in Br-Cl and Br-I close at low temperatures, while the Cl-I gap extends above room temperature. At temperatures above the miscibility gap (200 K to 500 K), all systems show a tendency toward layered halide ordering, with halide species preferentially occupying apical or equatorial octahedral sites. In CsPbBr3yI3-3y, this ordering occurs in a device-relevant temperature regime and is linked to the structural phase transitions, shifting transition temperatures by up to 100 K relative to randomly mixed structures. We attribute the strongly non-linear composition dependence of the orthorhombic-tetragonal phase boundary observed experimentally (a linear decrease followed by a plateau) to halide ordering. Introducing Rb on the A-site weakens halide ordering and eliminates the non-linear behavior, while narrowing the miscibility gap in both the Br-I and Br-Cl systems. These results establish halide ordering as a key determinant of structural phase stability in mixed-halide perovskites.
Materials Science (cond-mat.mtrl-sci)
Efficient protocol for the Markovian Mpemba effect in $N$-level systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
The Mpemba effect is an anomalous phenomenon in which the time to thermalize does not depend monotonically on the distance from equilibrium, allowing systems with an initially larger temperature difference to thermalize before those with a smaller one. The rarity of the effect makes it hard to find parameters that produce it, complicating the design of experiments and the development of applications. Here, we find necessary and sufficient conditions for the Markovian Mpemba effect in three-level systems and explain its underlying physical mechanisms. Based on our understanding of the three-level case, we develop an efficient algorithm to determine the parameters for the effect in $ N$ -level systems. This protocol could open the door for the realization of Mpemba experiments and related applications in large systems.
Statistical Mechanics (cond-mat.stat-mech)
SIM-GRAPH: A universal guide to symmetric interactions
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
R. C. Verstraten, C. Morais Smith
Symmetry plays a central role throughout physics, from Fourier analysis on discrete lattices to the classification of elementary particles in the standard model. In finite quantum systems, symmetries are often discrete, such as reflection and rotational symmetries. Here, we present the SIM-GRAPH method (Symmetric Ising Models - Graph Reduction And Projected Hamiltonians), which uses such symmetries to efficiently calculate ground-state observables of interacting quantum systems. By projecting all interactions onto a symmetric subset of the system, the method effectively reduces the number of sites, thus providing an exponential speedup over standard exact diagonalization. Furthermore, we introduce two extensions that broaden the applicability of the method and allow for a controlled trade-off between computational cost and accuracy.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
12 pages, 11 Figures
Effect of Spherical Confinement on the 2-TIPS of Soft Repulsive Spherocylinders
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
Jaydeep Mandal, Chandan Dasgupta, Prabal K. Maiti
We studied the 2-Temperature induced phase separation (2-TIPS) in a system of soft repulsive sphe rocylinders (SRS), confined on the surface of a sphere. We used two different anchoring conditions for the SRS on the spherical surface- free and tangential. For the free anchoring, increasing either the packing fraction or the rod aspect ratio suppresses phase separation between the active and passive subsystems, and the system corresponds to a dense-dilute phase co-existence. These phenomena can be explained via the trapping effect and are emergent due to the confinement. For the tangential anchoring, the system phase separates from its initial isotropic state into a locally ordered dense region and a disordered dilute region. Our work provides useful insights into phase separation in binary mixtures under spherical confinement.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
10 pages, 7 figures, submitted to Soft Matter for a themed collection
A machine-learned dynamical phase diagram of the one-dimensional nonlinear Schrödinger equation with quasiperiodic disorder and a static field
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-09-10 20:00 EDT
We map the transport regimes of a wave packet evolving under the one-dimensional discrete nonlinear Schrödinger (Gross-Pitaevskii) equation with a quasiperiodic Aubry-André potential and a static (Stark) field, as a function of self-interaction $ g$ , field $ F$ , and quasiperiodic strength $ \lambda$ , for two initial states (delta and Gaussian). Instead of one expensive long-time simulation per grid point, we run 3600 short simulations, reduce each to eight dynamical features, and cluster parameter space with a Gaussian mixture model. Clustering finds the boundaries between regimes unsupervised; each cluster’s name is then assigned by a hand-calibrated rule, and an ablation shows clustering measurably smooths those boundaries rather than merely relabeling them. The five resulting regimes (ballistic, localized, oscillatory-localized, subdiffusive, and self-trapped) are validated against 100 long runs on a lattice eight times larger than the short sweep, so the validation window is longer than the training window even for the fastest-spreading regime. The short-time clusters predict the long-time asymptotic spreading exponent ($ \alpha_\infty = 2.01\pm0.07$ ballistic, $ 0.28\pm0.16$ subdiffusive, consistent with the weak-chaos prediction $ \alpha=1/3$ ) and, independently, a long-time retention $ \Pi_0=0.72\pm0.32$ for the self-trapped cluster, whose exponent alone is not diagnostic. The initial-state contrast is striking: the delta state develops a broad self-trapping wedge (onset at $ g=3.907\pm0.017$ at $ \lambda=0$ ) that invades the ballistic and localized regions as $ g$ grows, while the Gaussian state shows no self-trapping, instead opening a subdiffusive corridor along the Aubry-André critical line that widens with $ g$ . The scheme yields a full $ 15\times15$ phase map in minutes per slice, where direct asymptotic simulation ($ t\gtrsim10^6$ per point) is prohibitive.
Quantum Gases (cond-mat.quant-gas)
Non-equilibrium dissipative stabilization of s- and d-wave superconductivity
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Aleksey Lunkin, Yury Holubeu, Denis Golež, Zala Lenarčič
Stabilizing superconductivity beyond its equilibrium regime has been one of the quests of nonequilibrium state engineering. We report the presence of nonthermal pairing gap in BCS superconductors coupled to two thermal baths, where one of the baths can be at a temperature well above the equilibrium $ T_c$ . Superconducting state is enabled by a highly non-equilibrium steady state stabilized by weak coupling to baths that break detailed balance condition. The steady-state is well described by a generalized Gibbs ensemble parametrized with chemical potentials for associated Bogoliubov quasiparticle. A strong, non-perturbative effect is reported for both $ s$ -wave and $ d$ -wave superconductors, and its possible realization in cavity-based experiments is discussed.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
11 pages, 7 figures
Observation of Magnetic-Anisotropy Crossover and High-Temperature Skyrmions in the Dirac Magnet Fe3Ge with a Distorted Kagome Lattice
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Yalei Huang, Xiaowei Lv, Bin Li, Chunqiang Xu, Dhanarajagopal Alltrin, Xiaoxuan Ma, Wanting Yang, Wei Zhou, Xiangzhuo Xing, Wen-Chin Lin, Raman Sankar, Michael Smidman, Shixun Cao, Dong Qian, Renchao Che, Xiaofeng Xu
Topological materials that simultaneously host robust high-temperature skyrmions and nontrivial electronic band structures have attracted tremendous interest owing to their distinctive advantages for both fundamental research and prospective technological applications. Here, we report the observation of robust skyrmions in the Dirac kagome magnet Fe3Ge, which exhibits a high Curie temperature of ~ 650 K. At room temperature, Fe3Ge shows a large intrinsic anomalous Hall conductivity of ~ 380 {\Omega}-1cm-1, originating from its nontrivial electronic band topology. Systematic magnetization measurements reveal a spin reorientation transition at ~ 375 K, indicating a crossover from easy-plane to easy-axis magnetic anisotropy. Below the spin reorientation temperature, a large topological Hall effect is observed, arising from microscopic noncoplanar spin structures. Lorentz transmission electron microscopy shows that mesoscopic skyrmions are stabilized in the easy-axis magnetic anisotropy regime and persist over an exceptionally wide temperature window of 375-650 K, far exceeding that of most previously reported skyrmion-hosting materials. These results establish Fe3Ge as a promising platform for exploring diverse topological properties, with strong potential for advancing future high-temperature spintronic applications, ranging from next-generation information storage to logic computing devices.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
5 figures
Advanced Science 2026
Infinite ergodic theory and functional statistics of non-confined Feller process
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
We study additive observables of a non-confined Feller process characterized by a non- normalizable stationary probability density and return times with infinite mean. The process is equivalent, after a deterministic rescaling, to a squared Bessel process, but we focus here on a question: the spatial structure of its local-time field. We show that the local time admits a fac- torization in the long time limit. Its spatial profile is governed by the non-normalizable stationary density, whereas its temporal fluctuations are controlled by a single Mittag-Leffler random ampli- tude. As a consequence, normalized spatial correlations of the local time converge to a universal constant independent of the two observation levels. Occupation times of finite intervals follow as corollaries and display Darling-Kac fluctuations. In contrast, non-integrable power observables exhibit self-similar squared-Bessel-type limits rather than Mittag-Leffler statistics. This spatial- field perspective provides a unifying framework for infinite ergodic theory under state-dependent multiplicative noise.
Statistical Mechanics (cond-mat.stat-mech), Probability (math.PR)
Reconfigurable field-free spin Hall nano-oscillators enabled by crystallographic anisotropy in epitaxial Co/Pt
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Jong-Guk Choi, Avinash Kumar Chaurasiya, Jaimin Kang, Venkatesh Vadde, Peter G. Lim, Roman Khymyn, Ahmad A. Awad, Akash Kumar, Mark C. Hersam, Vinayak P. Dravid, Pedram Khalili Amiri, Johan Åkerman
Spin Hall nano-oscillators (SHNOs) are nanoscale microwave sources for wireless communication, neuromorphic computing and oscillator-based Ising machines, but conventional devices require a global magnetic bias. Here we replace this bias through crystallographic anisotropy in epitaxial Co/Pt. Growth of hcp Co with its c-axis in the film plane produces an anisotropy field of about 0.36 T and enables field-free auto-oscillations above 10 GHz in nanoconstriction SHNOs. The active current polarity is selected by the remanent magnetization, providing nonvolatile reconfiguration of the oscillation state. Micro-focused Brillouin light scattering confirms that the nonlinear response is confined to the nanoconstriction region. Lithographic control of the angle between the current and anisotropy axes tunes the excitation threshold and drives two spectral branches from separated modes to a dominant single branch, consistent with mutual synchronization. These results establish epitaxial crystallographic anisotropy as a route to reconfigurable field-free spintronic oscillators and oscillator networks.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Anizotropic Ising Model on 2D Kagomé Lattice as an Inhomogeneous XYZ Integrable Model
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Shahane A. Khachatryan, Hrachya Babujian, Ara G. Sedrakyan
We investigate a generalized inhomogeneous two-dimensional Ising model on the kagomé lattice with two alternating couplings $ J_i$ and $ J’_i$ , $ i=1,2,3$ , along the three lattice directions. The local Boltzmann weights are mapped onto a non-symmetric eight-vertex $ R$ -matrix satisfying the free-fermion condition for arbitrary values of the six couplings. We analyze the Yang–Baxter structure for the cases $ J’_i=J_i$ and $ J’_i=-J_i$ and derive the corresponding one-dimensional quantum spin chains in the anisotropic limit. The first case yields a transverse-field Ising-type Hamiltonian, while the second leads to a modified chain with a graded permutation structure and shifted partition-function zeros. For a partially anisotropic model, we also obtain the free energy and specific heat.
Statistical Mechanics (cond-mat.stat-mech)
21 pages, 2 figures
Fast, Accurate, and Scalable Fermionic Neural Networks via Translation Equivariance
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
David D. Dai, Yen-Ting Lin, Marin Soljačić
We demonstrate that designing a neural quantum state to be an exact eigenstate of the Hamiltonian’s symmetries significantly improves both training speed and final variational energy. For the 2D electron gas, we design TorFormer, a neural network wavefunction which is an exact eigenstate of the total momentum. TorFormer describes both the Fermi liquid and Wigner crystal with no supervision and significantly outperforms Psiformer-based references up to large system sizes. For $ r_s = 30.0$ and $ 40.0$ at $ N=91$ , we compare TorFormer trained for $ 8\mathrm{K}$ steps against the previous best NQS, which required $ 100\mathrm{K}$ training steps. Our improvement to the total energy at $ r_s = 40.0$ , excluding the trivial Madelung part, is $ 0.12%$ —enormous compared to the tiny differences separating phases. Relative to Slater-Jastrow-backflow diffusion Monte Carlo, TorFormer’s energy decrease is roughly $ 9.8$ times that of the previous best NQS. Our work demonstrates that neural quantum states can both accurately and efficiently solve large-scale problems.
Strongly Correlated Electrons (cond-mat.str-el), Disordered Systems and Neural Networks (cond-mat.dis-nn), Materials Science (cond-mat.mtrl-sci)
7 pages, 5 figures, comments welcome!
Topology-dependent mixing of knots in flexible polymer chains
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
Souradeep Sengupta, Garima Mishra
The organization of multiple knots along a polymer contour can depend sensitively on the topology of the constituent knots. Using coarse-grained Brownian-dynamics simulations, we investigate topology-dependent mixing of two knots in a flexible polymer at controlled normalized wall separation. We compare homogeneous ($ 3_1\otimes 3_1$ ) and heterogeneous ($ 3_1\otimes 5_1$ ) knot pairs using a contour-based coordinate that distinguishes mixed and demixed configurations. Starting from partially overlapping configurations, the $ 3_1\otimes 5_1$ pair is observed in mixed configurations more frequently over the simulation time window than the $ 3_1\otimes 3_1$ pair at intermediate wall separation. We further find that, over the intermediate range of normalized wall separation, mixing of the $ 3_1\otimes5_1$ pair produces a composite knotted region that occupies substantially less polymer contour than the two constituent knots collectively occupy in demixed configurations. The corresponding reduction in contour occupancy is much smaller for the $ 3_1\otimes3_1$ pair. This indicates that the heterogeneous constituent topologies can be accommodated within a smaller portion of the polymer contour in the composite configuration. These results establish that constituent topology can strongly influence multiple-knot organization in flexible polymers.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
13 pages, 10 figures
pyeCE: A Python Implementation of the Embedded Cluster Expansion
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Yann L. Müller, Claire A. Paetsch, Anirudh Raju Natarajan
The cluster expansion is a widely used approach for predicting the finite-temperature thermodynamics of alloys from zero-kelvin first-principles calculations, but its conventional formulation becomes intractable for materials with more than three or four chemical species. High-entropy alloys have therefore remained largely out of reach. We present pyeCE, an open-source Python library that implements the embedded cluster expansion (eCE), in which machine learning maps many chemical species onto a smaller set of effective species and thereby limits the growth in the number of cluster functions. pyeCE provides the complete modeling workflow, including the construction of symmetry-adapted descriptors with a learnable per-sublattice chemical embedding, a neural-network energy model, ladder-based training, uncertainty quantification, and finite-temperature simulations through Monte Carlo sampling. Built on the PyTorch and pymatgen libraries, it supports systems with multiple species on multiple sublattices and runs on graphics processing units. We demonstrate the package on two material systems. In the first, a single model spanning the full composition space of a 9-component refractory alloy resolves short-range order and order–disorder behavior. This model enables rapid screening for compositions with strong Cr clustering, a feature linked to the formation of a continuous, corrosion-resistant oxide scale. In the second, a model of hydrogen dissolution in a Mo–Nb–W alloy reproduces the composition dependence of hydrogen uptake and resolves the interstitial environments that hydrogen occupies. The modular design of pyeCE allows it to be extended to problems beyond alloy thermodynamics, including kinetics, defect energetics, and the coupling of chemical order to magnetic and vibrational degrees of freedom.
Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
Beyond Impedance Additivity: A Systematic Nonlinear Perspective on Memristor Associations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Luiz A. Meneghetti Jr., Leonardo K. Castelano, Antônio Sérgio dos Santos, Soumen Pradhan, Fabian Hartmann, Ovidiu Lipan, Sven Höfling, Victor Lopez-Richard
We investigate the validity of the superposition principle and impedance additivity in AC circuits containing a memristive device connected in series with a resistor, capacitor, or inductor. While the series association of impedances is a cornerstone of linear circuit theory, its applicability to memory-bearing nonlinear systems remains largely unexplored. Using a state-dependent memristive model, we numerically analyze the stationary current response under sinusoidal excitation and characterize the resulting harmonic spectra, Bode diagrams, and Nyquist plots. To assess whether the fundamental response can still be interpreted through an equivalent-circuit framework, we introduce the concept of an apparent memristor, whose effective parameters are extracted directly from the composite impedance. We show that, although the fundamental harmonic can be accurately reproduced by an apparent equivalent circuit over selected parameter ranges, the effective parameters differ substantially from those of the isolated memristor, revealing a renormalization induced by the coupling to the passive element. More importantly, we identify parameter regimes in which the apparent-circuit description breaks down altogether, particularly for capacitor and inductor-coupled systems, demonstrating that the composite impedance cannot generally be expressed as the sum of independent impedances. These results establish boundaries for the use of equivalent-circuit models in memory-enabled electronic systems and provide practical guidelines for the interpretation of impedance spectroscopy in nonlinear devices exhibiting memory.
Materials Science (cond-mat.mtrl-sci)
25 pages, 6 figures
Nonlinear Edelstein effect in Rashba superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2026-09-10 20:00 EDT
We formulate a quasiclassical theory of the Edelstein effect in superconductors that incorporates both intraband and interband contributions. To describe the interband contribution, which is absent from the conventional leading-order quasiclassical formulation, we derive augmented Eilenberger equations in the presence of antisymmetric spin-orbit coupling. The intraband contribution is evaluated using multiband Eilenberger equations. We apply these formulations to supercurrent-induced surface spin magnetization in $ s$ -wave Rashba superconductors and investigate its dependence on temperature, distance from the surface, spin-orbit coupling strength, and supercurrent. The intraband contribution originates from a supercurrent-induced asymmetry of quasiparticles with opposite momenta and spin polarizations, whereas the interband contribution arises from the anomalous-velocity term generated by the momentum derivative of the Rashba spin-orbit potential. In the helicity basis, this anomalous-velocity term is expressed in terms of the Berry connection associated with the momentum dependence of the Rashba eigenstates. The intraband contribution increases linearly with the spin-orbit coupling strength, whereas the interband contribution exhibits a nonmonotonic dependence and is maximized when the Rashba spin splitting is comparable to the superconducting gap. Moreover, within the clean $ s$ -wave Rashba model considered here, we find that the nonlinear dependence of magnetization on the supercurrent arises solely from the interband contribution. Thus, although the intraband contribution dominates the linear Edelstein effect, the nonlinear Edelstein effect can serve as a useful probe of the interband contribution originating from quantum geometry.
Superconductivity (cond-mat.supr-con)
15 pages, 5 figures
Italian Business-to-Business Invoicing Data: A Network Analysis
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
We present a comprehensive description of the network of Italian Business-to-Business commercial relationships, based on the universe of electronic invoices collected by the Italian Tax Office. The firm-to-firm detail of the data is exploited to describe the distribution of the numbers of buyers (customers) and sellers (suppliers) per firm, the centrality of each firm in the production network, and the average distance between firms. We characterize for the first time the firm-to-firm network describing the Italian production system, and present its geographic and sectoral breakdown. The analysis reveals heavy tailed distributions for the numbers of buyers and sellers per firm, implying a scale-free structure of the network. The distributions of centrality values display heavy tails as well, indicating a strong concentration of importance in a relatively small number of firms. We estimate the tail exponents for all these distributions, finding in all cases lower exponents for downstream (buyer-side) distributions than for the upstream (seller-side) ones.
Statistical Mechanics (cond-mat.stat-mech), General Economics (econ.GN), Physics and Society (physics.soc-ph)
Physica A: Statistical Mechanics and its Applications, Volume 699, 2026, 13189
Characterizing particle rearrangements in sheared highly polydisperse materials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
We compare three particle-scale measures of rearrangement in highly polydisperse materials under driven flow: (a) nonaffine motion defined relative to the time-averaged mean flow, (b) changes in nearest-neighbor connectivity, and (c) $ D^2_{\min}$ , which measures nonaffine motion relative to an affine deformation fitted locally in space and time [Falk and Langer, Phys. Rev. E 57, 7192 (1998)]. We apply these measures to previously published two-dimensional simulations [Jiang, Sussman, and Weeks, Phys. Rev. E 108, 054605 (2023)] and granular-flow experiments [Illing and Weeks, Phys. Rev. E 111, 045422 (2025)] with polydispersities up to $ \delta\approx0.50$ . Changes in connectivity and $ D^2_{\min}$ both require a definition of neighboring particles, making the choice of neighborhood nontrivial in highly polydisperse systems. For detecting changes in connectivity, we recommend radical Delaunay triangulation, which provides a size-aware topological definition of neighbors. For calculating $ D^2_{\min}$ , we recommend a size-aware pairwise cutoff distance method. We further show that changing the neighborhood definition can reverse the apparent dependence of $ D^2_{\min}$ on particle size in experimental data. Thus, trends in $ D^2_{\min}$ cannot be interpreted independently of the neighborhood used to calculate it. Overall, the three measures presented provide complementary information about rearrangements in highly polydisperse systems.
Soft Condensed Matter (cond-mat.soft)
When particles come in every size, even deciding who counts as a neighbor can turn the story upside down. We show how that simple choice changes what you see when a material rearranges
Structural and Electronic Properties of Bulk $β$(2H)-GaSe from First-Principles DFT Calculations with van der Waals Corrections
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Julián A. Aros-González (1), Camilo A. Huertas-Archila (1), Miguel J. Espitia-Rico (1) ((1) Universidad Distrital Francisco José de Caldas, Bogotá, Colombia)
Gallium selenide (GaSe) is a layered III-VI semiconductor whose bulk crystal serves as the essential energetic reference for modeling the isolated monolayer. We present a systematic density-functional-theory (DFT) study of the centrosymmetric $ \beta$ (2H)-GaSe polymorph, employing the GGA-PBE functional supplemented with a semiempirical Grimme DFT-D2 dispersion correction to accurately capture the weak van der Waals interlayer coupling. The optimized in-plane lattice parameter agrees well with experimental values (within about 1.3%), while the out-of-plane parameter c is overestimated by the DFT-D2 correction relative to experiment, a known limitation of this dispersion scheme when the pairwise $ C_6$ coefficients are not specifically fitted for the compound class under study. Electronic structure calculations confirm a non-magnetic, direct-gap profile (1.12 eV). Although this magnitude reflects the well-known underestimation of semilocal functionals, the qualitative band topology accurately captures the intrinsic two-dimensional carrier confinement within the bulk material. Consequently, this optimized three-dimensional framework provides a consistent energetic baseline for quantifying exfoliation processes, offering a reliable starting point for future theoretical explorations of the two-dimensional limit, such as surface functionalization for potential spintronic applications.
Materials Science (cond-mat.mtrl-sci)
7 pages, 7 figures, 2 tables
Constrained Optimization of Higher-Order Cluster-Expansion Hamiltonians for Alloys Using Simulated Bifurcation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Kazuhide Ichikawa, Satoru Ohuchi, Tomoyasu Yokoyama, Takuma Saito, Yoshiki Matsuda
Identifying ground-state and low-energy atomic configurations is a central problem in alloy design. The cluster-expansion (CE) method represents configurational energetics on a fixed lattice as an effective Hamiltonian; for binary alloys, higher-order CE models become polynomial Ising Hamiltonians. Using Au-Cu as a model binary alloy, we formulate cubic and quartic cluster-expansion Hamiltonians as penalty-augmented polynomial unconstrained binary optimization (PUBO) problems under fixed-composition constraints. We optimize these PUBO problems using SQBM+, a simulated-bifurcation-based solver that can treat higher-order polynomial binary objectives directly. This direct PUBO treatment avoids the need to construct an explicit quadratic reformulation with auxiliary variables. Composition constraints are imposed through quadratic penalty terms, whose weights are estimated from derivative coefficients of the continuous relaxation of the CE objective. Benchmark calculations for systems up to 2048 atoms show that SQBM+ robustly obtains low-energy feasible configurations for cubic CE models and remains effective for many quartic instances. Formation-energy convex hulls constructed from the optimized configurations recover the CuAu and Cu3Au ordering trends and reveal finite-size effects at off-stoichiometric compositions. These results demonstrate simulated bifurcation as a practical route to constrained higher-order CE optimization for alloy configuration search.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
10 pages, 3 figures, and 1 table; Supplemental Material: 14 pages, 4 figures, and 9 tables
Quench dynamics in nonreciprocal Aubry-André-Harper model
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Zhiyu Pei, Yongxu Fu, Gao Xianlong
The critical phase of a non-Hermitian quasicrystal can support stronger transport than its surrounding delocalized phase. We demonstrate this anomalous behavior in the one-dimensional nonreciprocal Aubry-André-Harper model through a combined study of dynamical quantum phase transitions (DQPTs) and wavepacket diffusion. Using a parity-sorted energy-spectrum classification that directly encodes the generalized $ \mathcal{PT}$ symmetry, we find that DQPTs in this system are energy-resolved, in contrast to the energy-independent DQPTs of Hermitian quasicrystals. The energy-resolved features are most pronounced when the initial and final Hamiltonians belong to different phases (localized or extended), and they are tied to the even-odd index structure of the spectrum, which we exploit to organize the quench-dynamical landscape. For wavepacket dynamics after a single-site quench, the diffusion exponent $ \beta$ , extracted from the long-time power-law scaling of the root-mean-square displacement $ \sigma(\tau)$ , partitions the phase diagram into four distinct regimes. In the Hermitian limit the extended phase is ballistic ($ \beta=1$ ), the critical phase is normally diffusive ($ \beta=0.5$ ), and the localized phase yields $ \beta\to 0$ . Nonreciprocity reverses this hierarchy: the extended phase becomes normally diffusive, while the critical phase turns ballistic. We trace the anomalous $ \beta=1$ at criticality to the self-similar multifractal structure of the critical eigenstates, whose nodal positions are organized by the golden ratio. A finite-size scaling ansatz built on the wave-front propagation yields $ \sigma(\tau)\propto\tau$ . The parity-resolved DQPTs and the $ \beta$ -phase diagram establish two complementary dynamical diagnostics of nonreciprocal quasicrystals, in which nonreciprocity promotes transport at the critical point and suppresses it in the delocalized phase.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Spectroscopic signatures of mode-selective electron-phonon coupling in transient reflectivity change on charge-density-wave TiSe$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
We report on time- and spectrally resolved pump-probe spectroscopy measurement on the charge-density wave (CDW) state of TiSe$ _2$ at helium temperatures. The non-oscillatory component of the spectrally resolved signals exhibit a sign reversal near 1.5 eV, which was interpreted as a redshift of the optical transition energy originated from the interband transition between the Se $ p$ -based valence band to the Ti $ d$ -derived conduction band. Furthermore, the oscillatory components exhibit distinct spectral dependences between the optical phonons and the CDW-derived modes, suggesting the mode-selective coupling.
Materials Science (cond-mat.mtrl-sci)
Quantifying translational and bond-orientational order metrics in hyperuniform and nonhyperuniform many-particle systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
Anirban Mukherjee, Salvatore Torquato
Quantifying the degree of order/disorder in many-particle systems remains an outstanding problem in physics, materials science, and mathematics. To this end, we consider the translational order metric $ \tau_T$ , defined as the squared $ L^2$ norm of the total correlation function $ h(\mathbf{r})$ , and introduce its bond-orientational analogue $ \tau_O$ , defined from the weighted total correlation function $ h_{\mathbf{f}}(\mathbf{r})$ using local orientational weights (S. Torquato et al., Phys. Rev. X 16, 011042 (2026)). The pair $ (\tau_T,\tau_O)$ places both forms of order on a common two-point statistical footing. We compute both metrics for two nonhyperuniform sphere-packing models in 2D and 3D as functions of packing fraction $ \phi$ : 1) equilibrium hard particles and 2) nonequilibrium random sequential addition (RSA) packings. For the nonhyperuniform systems, bond-orientational order remains subdominant along the equilibrium-fluid and RSA configurations; however, its magnitude relative to the translational metric increases near the upper end of the equilibrium-fluid branches, much more strongly in 2D than in 3D, and the two metrics become comparable along the sampled crystal branches. At common packing fractions, equilibrium fluids and RSA packings trace distinct $ (\tau_T,\tau_O)$ trajectories, revealing preparation-dependent differences in structural order. As a representative hyperuniform family, we study 2D disordered stealthy hyperuniform (SHU) ground states for $ 0<\chi<1/2$ , where $ \chi$ is the stealthiness parameter. Within the disordered SHU phase, bond-orientational order remains subdominant, but its magnitude relative to the translational metric increases toward the disorder-to-order threshold. In all three models, $ \tau_T$ and $ \tau_O$ are positively correlated beyond the Poisson-reference regime: $ \tau_O$ increases monotonically with $ \tau_T$ across the sampled state points.
Statistical Mechanics (cond-mat.stat-mech), Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft)
17 pages, 24 figures
A First-Principles Multiscale Framework for Topological Superconductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2026-09-10 20:00 EDT
Christopher L. Jacobs, Baishali Mandal, Taehwan Jung, Purna P. Paudel, Jason Kawasaki, Tudor D. Stanescu, Subhasish Mandal
A microscopic understanding of topological superconductivity (TSC) in real materials requires a materials-informed approach that integrates first-principles electronic structure, superconductivity, and topology within a unified computational framework. Here, we develop such an approach by combining density functional theory, Wannier-based low-energy Hamiltonians, Bogoliubov-de Gennes theory, and Matsubara Green’s-function-based Chern number calculations performed directly on realistic multiorbital superconducting Hamiltonians. We apply this framework to bulk-like and monolayer FeTeSe and to FeSe/GaAs heterostructures, enabling a unified investigation of both intrinsic and proximity-induced topological superconductivity. We identify key electronic-structure ingredients that promote robust TSC, including Rashba-active states near the Fermi level, strong induced superconducting pairing, and substantial orbital hybridization between spin-orbit-active and superconducting sectors. Guided by these design principles, we predict multiple topological superconducting phases in Fe-based materials and demonstrate that FeSe/GaAs heterostructures are particularly promising, exhibiting topological transitions at experimentally accessible chemical potentials and low Zeeman fields. Complementing the theoretical predictions, we demonstrate the growth and structural characterization of FeSe/GaAs heterostructures, establishing the experimental feasibility of the proposed materials platform. Our results provide a quantitative route for engineering and screening candidate Majorana materials and heterostructures directly from realistic electronic structures and establish a foundation for future materials-by-design approaches to topological superconductivity.
Superconductivity (cond-mat.supr-con)
The Arithmetic of Spectra: Factorization, Statistics, and Symmetric Functions
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
We study factorizations of the single-particle spectrum of non-interacting quantum systems and their consequences for many-particle statistics. Representing the single-particle partition function by a spectral alphabet, tensor factorizations become multiplicative factorizations of the alphabet, which can be lifted to canonical Bose and Fermi partition functions using standard symmetric-function and $ \lambda$ -ring identities. We show how product spectra arise from different factorizations, how antisymmetrization can be assigned across an odd number of factors, and which tensor factorizations are compatible with a fixed spectrum. The paper therefore studies spectral factorization and provides a consolidated combinatorial framework for canonical Bose and Fermi partition functions.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph)
A Sharpened Entropy Principle for Two-Fluid Polymer Thermodynamics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-09-10 20:00 EDT
A compressible, non-isothermal dilute polymer solution is formulated as a Class-II binary mixture with separate solvent and polymer mass and momentum balances and with total energy and entropy balances for the complete mixture. The entropy exploitation is sharpened by a balance-anchoring axiom introduced here: in a fixed balance representative, each selected binary dissipative product contains a constitutive factor from an unclosed balance flux or source.
Polymer configuration is resolved first by a connector distribution and then by its conformation tensor. Population kinematics fix polymer transport and, by moments, yield a two-velocity upper-convected rate; objectivity verifies covariance rather than selecting it. Within the total entropy balance, configurational transport and deformation powers cancel their chemical-potential and elastic partial-stress counterparts when deformation and stress-decomposition weights match. A Gordon–Schowalter test independently requires the affine upper-convected choice for the stated dumbbell free energy and Kramers stress unless an additional reversible channel is supplied. Coordinated stress–interaction changes shift the local entropy flux/production pair by a divergence, exposing representation dependence of local mechanism-wise production.
An entropy-invariant Class-II-to-Class-I reduction selects a descendant entropy flux preserving the parent production and yields thermo-chemical, configurational-stress and partial-viscous-stress diffusion terms. The omitted quadratic relative-inertia flux is paired with relative kinetic-energy storage and transport and is a reversible truncation, not missing entropy production. The resulting compressible non-isothermal Hookean stress and temperature equations reduce to Oldroyd-B/UCM only after one-velocity, incompressible and isothermal limits.
Soft Condensed Matter (cond-mat.soft), Mathematical Physics (math-ph)
WannierNLQG: A Julia package for nonlinear optical responses and quantum geometry from Wannier tight-binding models
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Zhuocheng Lu, Zhichao Guo, Yuanyuan Xua, Jiacheng Yao, Hua Wang
Nonlinear optical responses and quantum geometry are central to modern condensed matter physics and are deeply intertwined. We introduce WannierNLQG, an extensible Julia framework for computing nonlinear optical responses and quantum geometric quantities from Wannier tight-binding models. Its gauge-consistent, degeneracy-aware architecture accommodates perturbative responses at arbitrary order and additional quantum geometric quantities. The current release evaluates ordinary, spin, and photon-drag injection and shift currents, as Brillouin-zone integrals and on k slices. For shift current, a unified interface exposes four complementary formulations: the conventional method, projector trace, generalized Wilson loop, and a finite-momentum geometric loop, with the last three explicitly accommodating degenerate subspaces. The framework also provides k-resolved Berry curvature, quantum metric, their multipoles, and additional quantum geometric and mixed momentum-spin quantities. Experimental symmetry workflows additionally support symmetry-adapted Wannier construction, symmetrization of tight-binding models and real-space operators, and reduction of spatially uniform response integrals to irreducible k-point orbits and invariant tensor components. The documentation covers formula conventions, the TaskConfig interface, and auditable output formats, with GeS and bilayer MoS2 case studies illustrating method comparison, degeneracy handling, quantum geometric analysis, and photon-drag responses. Together, these capabilities enable first-principles calculations of nonlinear response and quantum geometry in realistic multiband materials, connecting quantum geometry with quantitative materials modeling for optoelectronic, spintronic, and photovoltaic applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
22 pages, 5 figures
Overcoming Transport Layer Bottlenecks to Quantify Ionic Parameters from Transient Ion Current Measurements of Perovskite Solar Cells
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-09-10 20:00 EDT
Shudi Jiao, Miguel Torre Cachafeiro, Huagui Lai, Fuxiang Ji, Tristan Sachsenweger Ballantyne, Sharun Parayil Shaji, Matthias Diethelm, Fan Fu, Wei E.I. Sha, Wolfgang Tress
In perovskite solar cells (PSCs), voltage step-induced transient ion current (TIC) measurements, commonly referred to as bias-assisted charge extraction (BACE), are frequently used to quantify ion density. Drift-diffusion simulations predict that the ion density computed from TIC saturates once mobile ions screen the electric field in the perovskite. However, experimental studies often report ion densities orders of magnitude above this limit, whose physical origin remains incompletely explained in terms of transport layer (TL) properties. In this work, the capacitance of the TLs is identified to be the fundamental bottleneck: the maximum quantifiable ion density is limited to the charge that can accumulate at the perovskite/TL interfaces, so that TIC most often depends more strongly on TL properties than on the ionic properties of the perovskite. Experiments with systematically varied C$ _{\rm 60}$ electron-TL thickness (p-i-n) and Spiro-OMeTAD hole-TL doping (n-i-p) confirm this dependence across architectures. To overcome this limitation, the importance of a correction based on the average ionic displacement is discussed, and it is shown how extrapolating the TL-thickness trend towards the TL-free situation yields the actual ionic conductivity of the absorber, alongside density and mobility, depending on the assumed ionic model. Simulations are also examined in which ion penetration into the TLs or initial accumulation under forward bias raise the capacitive limit and extend TIC sensitivity to higher ion densities. The slow release of trapped carriers is also discussed as a potential source of current which can inflate the TIC signal. Overall, the presented analysis provides important practical considerations for interpreting TIC and quantifying ionic properties in PSCs.
Materials Science (cond-mat.mtrl-sci)
Gauge mean-field theories of the underscreened Kondo lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-09-10 20:00 EDT
Various mean-field decoupling schemes have been introduced thus far to study the important and challenging problem of the spin-$ 1$ underscreened Kondo lattice where magnetic order can coexist with Kondo hybridization. We use a single control parameter $ N$ and an unbiased variational ansatz to unify and connect the previously proposed decouplings to standard Read-Newns theory, where fluctuations are small in $ 1/N$ . We compute the corrections around the large-$ N$ limit. In particular, we make contact with Nozières strong-coupling theory by finding the residual ferromagnetic Hund interaction that decays logarithmically in the case of a heavy-fermion metal. We map out the ground state phase diagram as a function of $ N$ and the Kondo coupling. We find crucial differences between the previously proposed mean-field theories in the strength of the hybridization and total magnetization of the coexistent phase. We show that, within our unifying variational theory, the previously proposed decouplings correspond to either taking $ N=2$ from the start, or performing a $ 1/N$ expansion and then extrapolating to $ N=2$ . Finally, we summarize the generalization of our theory to $ S>1$ .
Strongly Correlated Electrons (cond-mat.str-el)
Protected domains and the cost of cooperation on weighted networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
A costly inherited trait can spread when its descendants create a favorable local environment. We ask which finite contact structures sustain such a collective competitor and what their advantage costs. Individuals play a donation game, conferring benefit $ b$ at cost $ c$ . Reciprocal weighted contacts determine averaged payoffs and copying recipients, while sources are chosen globally according to payoff. Cooperation is favored when a uniformly introduced cooperator takes over more often than a defector in the complementary experiment. Exact fluctuation response and elimination of fast configurations identify the formation and competition of protected domains as the controlling processes. The sharp weak-selection threshold infima are $ b/c=3$ on the four-cycle, $ 7$ on the five-site path, and $ 1$ on every fixed path with at least six sites. On the six-site path, a global bound forces near-barrier designs into this domain hierarchy. Polynomial relations among the contact ratios then control unrestricted optimization and imply eventual exact reflection symmetry. Reaching threshold $ 1+\epsilon$ requires minimum contact contrast $ 656\epsilon^{-2}[1+O(\epsilon)]$ and neutral absorption time of order $ \epsilon^{-1}$ . We determine their tradeoff and the associated design tolerance. Finite selection consumes the same margin. Within the controlled small-selection window, the maximal fixation advantage is of order $ \epsilon^{5/2}$ when the contrast exceeds its exact minimum by order $ \epsilon^{-1}$ . Thus an improving invasion threshold can require increasing contact heterogeneity, precision and observation time.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph), Populations and Evolution (q-bio.PE)
47 pages including appendices, 6 figures, 3 tables
Phonon-Bottleneck-Governed Ultrafast Hot-Carrier Super-Diffusion in Transition Metal Dichalcogenides
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Yuwei Zhang, Dongyang Wan, Tao Zhou, Hao Wu, Junpeng Lu, Zhenhua Ni
Two-dimensional transition metal dichalcogenides (TMDCs) are promising for low-power optoelectronics, yet their operational speed is widely considered constrained by low room-temperature mobilities and carrier transit delays. Here, by combining on-chip terahertz optoelectronic sampling with thermally evaporated Ohmic contacts, we eliminate external parasitic delays and directly capture the intrinsic interfacial photoresponse in unencapsulated TMDCs under zero bias. The devices achieve ultrafast relaxation lifetimes of 48.5 ps in MoS2/Au and 14.2 ps in MoSe2/Ag, translating to intrinsic 3-dB bandwidths of 4.4 GHz and 7.5 GHz, respectively. Spatial scanning and bias-dependent measurements show that this response is position-independent and bias-immune, ruling out conventional drift-limited transport and identifying hot-carrier super-diffusion driven by an interfacial electron temperature gradient as the operative mechanism. Furthermore, ultrafast pump-probe spectroscopy reveals that the macroscopic response time is quantitatively synchronized with the microscopic optical-to-acoustic phonon scattering lifetime governed by the intrinsic phonon bottleneck. Our findings establish phonon engineering as a viable paradigm to tailor non-equilibrium optoelectronic dynamics, offering a blueprint for zero-bias, ultrafast, self-powered devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Hydrodynamic magnetotransport in a GaAs Corbino geometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
A. D. Levin, A. S. Jaroshevich, Z. D. Kvon, V. A. Chitta, M. S. Aksenov, D. V. Dmitriev, A. K. Bakarov, G. M. Gusev
We report the observation of positive magnetoresistance in high-mobility GaAs Corbino devices. Over a broad intermediate-temperature range, the resistance exhibits a quadratic dependence on perpendicular magnetic field. We analyze the data within hydrodynamic theories of magnetotransport in the Corbino geometry, which describe the crossover between the diffusive and viscous regimes, including finite-slip boundary conditions appropriate for current-penetrable contacts. The extracted relaxation rates are consistent with an approximately $ T^2$ temperature dependence of the electron-electron scattering contribution. The extracted viscous relaxation parameters are consistent with those obtained from Hall-bar measurements. Comparison with theory indicates that the observed magnetoresistance is predominantly governed by the bulk hydrodynamic response, while finite slip modifies the Stokes–Ohm crossover quantitatively and the field-dependent boundary voltage provides a separate correction. These results show that Corbino magnetotransport can serve as a complementary bulk-sensitive probe of viscous electron flow.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 5 figures
Optimal Intermediate Hamiltonians for Non-Equilibrium Free Energy Calculations: A Numerical Study of Markov Models
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-09-10 20:00 EDT
David Beyer, Helmut Grubmüller
The Jarzynski relation enables the estimation of equilibrium free energy differences from non-equilibrium, finite-time switching simulations. These estimates usually converge poorly because rare trajectories dominate the exponential work average. Here, we numerically determined and explored the sequence of intermediate Hamiltonians connecting initial and final states that minimize the mean squared error (MSE) of the Jarzynski estimator and thereby enhance convergence. For discrete-time Markov models, an exact tilted-master-equation representation of the MSE in the large-sample limit, combined with automatic differentiation, enables efficient gradient-based minimization over all intermediate energies. We applied our approach to three model systems of increasing complexity: a two-state model, a double-well potential, and a shifted potential well. In all three systems, the optimal intermediate Hamiltonians jump at the initial and final times. Extensive Monte Carlo simulations show that optimal intermediates can reduce the MSE by more than an order of magnitude compared with linear and logarithmic interpolation, most strongly for large changes in the energy landscape. Remarkably, they need not dissipate less work than intermediates yielding larger errors. Our results suggest heuristics for more efficient non-equilibrium free energy calculations of realistic molecular systems: optimal intermediate Hamiltonians jump at the initial and final times; for barrier-crossing problems, the barrier should be lowered rapidly and raised again later; and minimizing dissipation does not guarantee faster convergence.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
15 pages, 5 figures
Symplectic Hopf Insulator: Delicate Topology in Bosonic Bogoliubov-de Gennes Systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-09-10 20:00 EDT
Isaac Tesfaye, Giandomenico Palumbo
Recent advances in topological phases have highlighted the role of symplectic (Krein-space) topology in the classification of bosonic Bogoliubov-de Gennes (BBdG) systems. In this work, we construct a BBdG realization of Hopf topology, which we dub the symplectic Hopf insulator, starting from a microscopic Bose-Hubbard generalization of the Moore-Ran-Wen model with weak on-site interactions treated within a Bogoliubov approximation. The resulting BBdG system admits a symplectic Hopf invariant, which we show to be integer-quantized for isolated bands. We establish that this topology is intrinsically delicate, requiring exactly two bosonic modes per unit cell, while remaining robust against weak interactions over a range of mass parameters. Upon terminating the three-dimensional insulator at a boundary, we find topologically protected in-gap surface states at finite excitation energy, whose protection is itself delicate. Our results establish the symplectic Hopf insulator as a robust yet delicate topological phase in weakly interacting bosonic systems lying beyond the tenfold-way classification.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas)
7 pages + 3 figures. Comments are welcome
Research Square
Evolution of memory strategies in alternating stochastic games
Article | Complex networks | 2026-09-09 20:00 EDT
Zhihai Rong, Jing Zhang, Zhi-Xi Wu, Bin Xu, Xiaofan Wang
Stochastic games provide a powerful theoretical framework for capturing the feedback between individual behavior and environmental states, yet most existing studies assume that players interact synchronously. Here, we investigate the evolution of classical pure memory-one strategies in alternating stochastic games, in which players take turns making decisions based on historical outcomes and subsequently altering the environmental state. By analyzing the equilibrium conditions of pure memory-one strategies, we show through theoretical and numerical results that environmental feedback can substantially promote cooperation under alternating interactions. In particular, sustaining cooperation relies primarily on the firm-but-fair (FBF) strategy rather than the celebrated win-stay, lose-shift (WSLS) strategy. Moreover, when the environmental transition mechanism incentivizes mutual cooperation by maintaining a good state and penalizes any defection by switching the environment to a bad state, the population can form a stable, multi-strategy cooperative alliance that collectively sustains cooperation. These findings remain robust under both rare and positive mutation rates, providing novel insights into how environmental feedback and sequential interactions jointly shape the evolution of cooperation.
Research Square:rs-10775518 (2026)
Posted on Research Square and Under Review at Nature Portfolio
Physical sciences/Physics/Statistical physics, thermodynamics and nonlinear dynamics/Complex networks, Physical sciences/Physics/Statistical physics, thermodynamics and nonlinear dynamics/Statistical physics