CMP Journal 2025-04-23
Statistics
Nature: 23
Nature Materials: 2
Nature Nanotechnology: 3
Nature Physics: 1
Physical Review Letters: 12
Physical Review X: 1
arXiv: 42
Nature
Whole-body physics simulation of fruit fly locomotion
Original Paper | Biophysical models | 2025-04-22 20:00 EDT
Roman Vaxenburg, Igor Siwanowicz, Josh Merel, Alice A. Robie, Carmen Morrow, Guido Novati, Zinovia Stefanidi, Gert-Jan Both, Gwyneth M. Card, Michael B. Reiser, Matthew M. Botvinick, Kristin M. Branson, Yuval Tassa, Srinivas C. Turaga
The body of an animal influences how its nervous system generates behavior1. Accurately modeling the neural control of sensorimotor behavior requires an anatomically detailed biomechanical representation of the body. Here, we introduce a whole-body model of the fruit fly Drosophila melanogaster in a physics simulator2. Designed as a general-purpose framework, our model enables the simulation of diverse fly behaviors, including both terrestrial and aerial locomotion. We validate its versatility by replicating realistic walking and flight behaviors. To support these behaviors, we develop new phenomenological models for fluid and adhesion forces. Using data-driven, end-to-end reinforcement learning3,4, we train neural network controllers capable of generating naturalistic locomotion5,6,7 along complex trajectories in response to high-level steering commands. Additionally, we show the use of visual sensors and hierarchical motor control8, training a high-level controller to reuse a pre-trained low-level flight controller to perform visually guided flight tasks. Our model serves as an open-source platform for studying the neural control of sensorimotor behavior in an embodied context.
Biophysical models, Computational models
Geographic and age variations in mutational processes in colorectal cancer
Original Paper | Cancer epidemiology | 2025-04-22 20:00 EDT
Marcos Díaz-Gay, Wellington dos Santos, Sarah Moody, Mariya Kazachkova, Ammal Abbasi, Christopher D. Steele, Raviteja Vangara, Sergey Senkin, Jingwei Wang, Stephen Fitzgerald, Erik N. Bergstrom, Azhar Khandekar, Burçak Otlu, Behnoush Abedi-Ardekani, Ana Carolina de Carvalho, Thomas Cattiaux, Ricardo Cortez Cardoso Penha, Valérie Gaborieau, Priscilia Chopard, Christine Carreira, Saamin Cheema, Calli Latimer, Jon W. Teague, Anush Mukeriya, David Zaridze, Riley Cox, Monique Albert, Larry Phouthavongsy, Steven Gallinger, Reza Malekzadeh, Ahmadreza Niavarani, Marko Miladinov, Katarina Erić, Sasa Milosavljevic, Suleeporn Sangrajrang, Maria Paula Curado, Samuel Aguiar, Rui Manuel Reis, Monise Tadin Reis, Luis Gustavo Romagnolo, Denise Peixoto Guimarães, Ivana Holcatova, Jaroslav Kalvach, Carlos Alberto Vaccaro, Tamara Alejandra Piñero, Beata Świątkowska, Jolanta Lissowska, Katarzyna Roszkowska-Purska, Antonio Huertas-Salgado, Tatsuhiro Shibata, Satoshi Shiba, Surasak Sangkhathat, Taned Chitapanarux, Gholamreza Roshandel, Patricia Ashton-Prolla, Daniel C. Damin, Francine Hehn de Oliveira, Laura Humphreys, Trevor D. Lawley, Sandra Perdomo, Michael R. Stratton, Paul Brennan, Ludmil B. Alexandrov
Colorectal cancer incidence rates vary geographically and have changed over time1. Notably, in the past two decades, the incidence of early-onset colorectal cancer, affecting individuals under the age of 50 years, has doubled in many countries2-5. The reasons for this increase are unknown. Here, we investigate whether mutational processes contribute to geographic and age-related differences by examining 981 colorectal cancer genomes from 11 countries. No major differences were found in microsatellite unstable cancers, but variations in mutation burden and signatures were observed in the 802 microsatellite-stable cases. Multiple signatures, most with unknown etiologies, exhibited varying prevalence in Argentina, Brazil, Colombia, Russia, and Thailand, indicating geographically diverse levels of mutagenic exposure. Signatures SBS88 and ID18, caused by the bacteria-produced mutagen colibactin6,7, had higher mutation loads in countries with higher colorectal cancer incidence rates. SBS88 and ID18 were also enriched in early-onset colorectal cancers, being 3.3 times more common in individuals diagnosed before age 40 than in those over 70, and were imprinted early during colorectal cancer development. Colibactin exposure was further linked to APC driver mutations, with ID18 responsible for about 25% of APC driver indels in colibactin-positive cases. This study reveals geographic and age-related variations in colorectal cancer mutational processes, and suggests that early-life mutagenic exposure to colibactin-producing bacteria may contribute to the rising incidence of early-onset colorectal cancer.
Cancer epidemiology, Cancer genomics, Colorectal cancer
Psychedelic control of neuroimmune interactions governing fear
Original Paper | Inflammatory diseases | 2025-04-22 20:00 EDT
Elizabeth N. Chung, Jinsu Lee, Carolina M. Polonio, Joshua Choi, Camilo Faust Akl, Michael Kilian, Wiebke M. Weiß, Georgia Gunner, Mingyu Ye, Tae Hyun Heo, Sienna S. Drake, Liu Yang, Catarina R. G. L. d’Eca, Joon-Hyuk Lee, Liwen Deng, Daniel Farrenkopf, Anton M. Schüle, Hong-Gyun Lee, Oreoluwa Afolabi, Sharmin Ghaznavi, Stelios M. Smirnakis, Isaac M. Chiu, Vijay K. Kuchroo, Francisco J. Quintana, Michael A. Wheeler
Neuroimmune interactions–signals transmitted between immune and brain cells–regulate many aspects of tissue physiology1, including responses to psychological stress2,3,4,5, which can predispose individuals to develop neuropsychiatric diseases6,7,8,9. Still, the interactions between haematopoietic and brain-resident cells that influence complex behaviours are poorly understood. Here, we use a combination of genomic and behavioural screens to show that astrocytes in the amygdala limit stress-induced fear behaviour through epidermal growth factor receptor (EGFR). Mechanistically, EGFR expression in amygdala astrocytes inhibits a stress-induced, pro-inflammatory signal-transduction cascade that facilitates neuron-glial crosstalk and stress-induced fear behaviour through the orphan nuclear receptor NR2F2 in amygdala neurons. In turn, decreased EGFR signalling and fear behaviour are associated with the recruitment of meningeal monocytes during chronic stress. This set of neuroimmune interactions is therapeutically targetable through the administration of psychedelic compounds, which reversed the accumulation of monocytes in the brain meninges along with fear behaviour. Together with validation in clinical samples, these data suggest that psychedelics can be used to target neuroimmune interactions relevant to neuropsychiatric disorders and potentially other inflammatory diseases.
Inflammatory diseases, Neuroimmunology
Superconducting gap of H3S measured by tunnelling spectroscopy
Original Paper | Superconducting properties and materials | 2025-04-22 20:00 EDT
Feng Du, Alexander P. Drozdov, Vasily S. Minkov, Fedor F. Balakirev, Panpan Kong, G. Alexander Smith, Jiafeng Yan, Bin Shen, Philipp Gegenwart, Mikhail I. Eremets
Several hydrogen-rich superconductors have been found to show unprecedentedly high critical temperatures1,2,3,4, stimulating investigations into the nature of the superconductivity in these materials. Although their macroscopic superconducting properties are established1,5,6,7, microscopic insights into the pairing mechanism remains unclear. Here we characterize the superconducting gap structure in the high-temperature superconductor H3S and its deuterium counterpart D3S by performing tunnelling spectroscopy measurements. The tunnelling spectra reveal that H3S and D3S both have a fully gapped structure, which could be well described by a single s-wave Dynes model, with gap values 2Δ of approximately 60 meV and 44 meV, respectively. Furthermore, we observed gap features of another likely H-depleted HxS superconducting phase in a poorly synthesized hydrogen sulfide sample. Our work offers direct experimental evidence for superconductivity in the hydrogen-rich superconductor H3S from a microscopic perspective. It validates the phonon-mediated mechanism of superconducting pairing and provides a foundation for further understanding the origins of high-temperature superconductivity in hydrogen-rich compounds.
Superconducting properties and materials
Carbon majors and the scientific case for climate liability
Review Paper | Attribution | 2025-04-22 20:00 EDT
Christopher W. Callahan, Justin S. Mankin
Will it ever be possible to sue anyone for damaging the climate? Twenty years after this question was first posed, we argue that the scientific case for climate liability is closed. Here we detail the scientific and legal implications of an ‘end-to-end’ attribution that links fossil fuel producers to specific damages from warming. Using scope 1 and 3 emissions data from major fossil fuel companies, peer-reviewed attribution methods and advances in empirical climate economics, we illustrate the trillions in economic losses attributable to the extreme heat caused by emissions from individual companies. Emissions linked to Chevron, the highest-emitting investor-owned company in our data, for example, very likely caused between US $791 billion and $3.6 trillion in heat-related losses over the period 1991-2020, disproportionately harming the tropical regions least culpable for warming. More broadly, we outline a transparent, reproducible and flexible framework that formalizes how end-to-end attribution could inform litigation by assessing whose emissions are responsible and for which harms. Drawing quantitative linkages between individual emitters and particularized harms is now feasible, making science no longer an obstacle to the justiciability of climate liability claims.
Attribution, Climate change
Deciphering disordered regions controlling mRNA decay in high-throughput
Original Paper | High-throughput screening | 2025-04-22 20:00 EDT
Joseph H. Lobel, Nicholas T. Ingolia
Intrinsically disordered regions within proteins drive specific molecular functions despite lacking a defined structure1,2. Although disordered regions are integral to controlling mRNA stability and translation, the mechanisms underlying these regulatory effects remain unclear3. Here we reveal the molecular determinants of this activity using high-throughput functional profiling. Systematic mutagenesis across hundreds of regulatory disordered elements, combined with machine learning, reveals a complex pattern of molecular features important for their activity. The presence and arrangement of aromatic residues strongly predicts the ability of seemingly diverse protein sequences to influence mRNA stability and translation. We further show how many of these regulatory elements exert their effects by engaging core mRNA decay machinery. Our results define molecular features and biochemical pathways that explain how disordered regions control mRNA expression and shed light on broader principles within functional, unstructured proteins.
High-throughput screening, Intrinsically disordered proteins, RNA metabolism
Cold memories control whole-body thermoregulatory responses
Original Paper | Classical conditioning | 2025-04-22 20:00 EDT
Andrea Muñoz Zamora, Aaron Douglas, Paul B. Conway, Esteban Urrieta, Taylor Moniz, James D. O’Leary, Lydia Marks, Christine A. Denny, Clara Ortega-de San Luis, Lydia Lynch, Tomás J. Ryan
Environmental thermal challenges trigger the brain to coordinate both autonomic and behavioural responses to maintain optimal body temperature1,2,3,4. It is unknown how temperature information is precisely stored and retrieved in the brain and how it is converted into a physiological response. Here we investigated whether memories could control whole-body metabolism by training mice to remember a thermal challenge. Mice were conditioned to associate a context with a specific temperature by combining thermoregulatory Pavlovian conditioning with engram-labelling technology, optogenetics and chemogenetics. We report that if mice are returned to an environment in which they previously experienced a 4 °C cold challenge, they increase their metabolic rates regardless of the actual environmental temperature. Furthermore, we show that mice have increased hypothalamic activity when they are exposed to the cold, and that a specific network emerges between the hippocampus and the hypothalamus during the recall of a cold memory. Both natural retrieval and artificial reactivation of cold-sensitive memory engrams in the hippocampus mimic the physiological responses that are seen during a cold challenge. These ensembles are necessary for cold-memory retrieval. These findings show that retrieval of a cold memory causes whole-body autonomic and behavioural responses that enable mice to maintain thermal homeostasis.
Classical conditioning, Learning and memory, Long-term memory, Neuroimmunology
Atomic lift-off of epitaxial membranes for cooling-free infrared detection
Original Paper | Nanoscale materials | 2025-04-22 20:00 EDT
Xinyuan Zhang, Owen Ericksen, Sangho Lee, Marx Akl, Min-Kyu Song, Haihui Lan, Pratap Pal, Jun Min Suh, Shane Lindemann, Jung-El Ryu, Yanjie Shao, Xudong Zheng, Ne Myo Han, Bikram Bhatia, Hyunseok Kim, Hyun S. Kum, Celesta S. Chang, Yunfeng Shi, Chang-Beom Eom, Jeehwan Kim
Recent breakthroughs in ultrathin, single-crystalline, freestanding complex oxide systems have sparked industry interest in their potential for next-generation commercial devices1,2. However, the mass production of these ultrathin complex oxide membranes has been hindered by the challenging requirement of inserting an artificial release layer between the epilayers and substrates3,4. Here we introduce a technique that achieves atomic precision lift-off of ultrathin membranes without artificial release layers to facilitate the high-throughput production of scalable, ultrathin, freestanding perovskite systems. Leveraging both theoretical insights and empirical evidence, we have identified the pivotal role of lead in weakening the interface. This insight has led to the creation of a universal exfoliation strategy that enables the production of diverse ultrathin perovskite membranes less than 10 nm. Our pyroelectric membranes demonstrate a record-high pyroelectric coefficient of 1.76 × 10-2 C m-2 K-1, attributed to their exceptionally low thickness and freestanding nature. Moreover, this method offers an approach to manufacturing cooling-free detectors that can cover the full far-infrared spectrum, marking a notable advancement in detector technology5.
Nanoscale materials
Effects of glacial forcing on lithospheric motion and ridge spreading
Original Paper | Climate sciences | 2025-04-22 20:00 EDT
Tao Yuan, Shijie Zhong
Glacial cycles significantly influenced Earth’s surface processes throughout the Quaternary, impacting the climate, sea level, and seismic and magmatic activity1,2,3. However, the effects of glaciation and deglaciation (that is, glacial forcing) on lithospheric motion are unknown. To study these effects, we formulated high-resolution numerical models with realistic lithospheric structures, including weak plate margins, lithospheric thickness variations and crustal structure. Our results show that glacial forcing significantly altered lithospheric motion and the spreading rates of mid-ocean ridges situated near major ice sheets in the last glacial cycle. For example, deglaciation-induced motion in the North American plate had a rotational part that was up to around 25% of its tectonic plate motion over 10,000-year timescales. The deglaciation in Greenland and Fennoscandia caused up to 40% fluctuations in the spreading rates of the Iceland Ridge between 12,000 and 6,000 years ago, which may explain the Holocene volcanism in Iceland. Our modelling also indicates increased (decreased) rates of global sea-floor production during the deglaciation (glaciation) periods with implications for mantle degassing rates. These results underscore the critical dynamic interplay between glacial cycles, lithospheric motion, ridge spreading and climate during ice ages.
Climate sciences, Solid Earth sciences
Long-distance coherent quantum communications in deployed telecom networks
Original Paper | Fibre optics and optical communications | 2025-04-22 20:00 EDT
Mirko Pittaluga, Yuen San Lo, Adam Brzosko, Robert I. Woodward, Davide Scalcon, Matthew S. Winnel, Thomas Roger, James F. Dynes, Kim A. Owen, Sergio Juárez, Piotr Rydlichowski, Domenico Vicinanza, Guy Roberts, Andrew J. Shields
Recent advances in quantum communications have underscored the crucial role of optical coherence in developing quantum networks. This resource, which is fundamental to the phase-based architecture of the quantum internet1, has enabled the only successful demonstrations of multi-node quantum networks2,3,4 and substantially extended the range of quantum key distribution (QKD)5. However, the scalability of coherence-based quantum protocols remains uncertain owing to the specialized hardware required, such as ultra-stable optical cavities and cryogenic photon detectors. Here we implement the coherence-based twin-field QKD protocol over a 254-kilometre commercial telecom network spanning between Frankfurt and Kehl, Germany, achieving encryption key distribution at 110 bits per second. Our results are enabled by a scalable approach to optical coherence distribution, supported by a practical system architecture and non-cryogenic single-photon detection aided by off-band phase stabilization. Our results demonstrate repeater-like quantum communication in an operational network setting, doubling the distance for practical real-world QKD implementations without cryogenic cooling. In addition, to our knowledge, we realized one of the largest QKD networks featuring measurement-device-independent properties6. Our research aligns the requirements of coherence-based quantum communication with the capabilities of existing telecommunication infrastructure, which is likely to be useful to the future of high-performance quantum networks, including the implementation of advanced quantum communication protocols, quantum repeaters, quantum sensing networks and distributed quantum computing7.
Fibre optics and optical communications, Information technology, Quantum information, Quantum optics
BMAL1-HIF2A heterodimer modulates circadian variations of myocardial injury
Original Paper | Circadian rhythms | 2025-04-22 20:00 EDT
Wei Ruan, Tao Li, In Hyuk Bang, Jaewoong Lee, Wankun Deng, Xinxin Ma, Cong Luo, Fang Du, Seung-Hee Yoo, Boyun Kim, Jiwen Li, Xiaoyi Yuan, Katherine Figarella, Yu A. An, Yin-Ying Wang, Yafen Liang, Matthew DeBerge, Dongze Zhang, Zhen Zhou, Yanyu Wang, Joshua M. Gorham, Jonathan G. Seidman, Christine E. Seidman, Sary F. Aranki, Ragini Nair, Lei Li, Jagat Narula, Zhongming Zhao, Alemayehu A. Gorfe, Jochen D. Muehlschlegel, Kuang-Lei Tsai, Holger K. Eltzschig
Acute myocardial infarction is a leading cause of morbidity and mortality worldwide1. Clinical studies have shown that the severity of cardiac injury after myocardial infarction exhibits a circadian pattern, with larger infarcts and poorer outcomes in patients experiencing morning-onset events2,3,4,5,6,7. However, the molecular mechanisms underlying these diurnal variations remain unclear. Here we show that the core circadian transcription factor BMAL17,8,9,10,11 regulates circadian-dependent myocardial injury by forming a transcriptionally active heterodimer with a non-canonical partner–hypoxia-inducible factor 2 alpha (HIF2A)12,13,14,15,16–in a diurnal manner. To substantiate this finding, we determined the cryo-EM structure of the BMAL1-HIF2A-DNA complex, revealing structural rearrangements within BMAL1 that enable cross-talk between circadian rhythms and hypoxia signalling. BMAL1 modulates the circadian hypoxic response by enhancing the transcriptional activity of HIF2A and stabilizing the HIF2A protein. We further identified amphiregulin (AREG)16,17 as a rhythmic target of the BMAL1-HIF2A complex, critical for regulating daytime variations of myocardial injury. Pharmacologically targeting the BMAL1-HIF2A-AREG pathway provides cardioprotection, with maximum efficacy when aligned with the pathway’s circadian phase. These findings identify a mechanism governing circadian variations of myocardial injury and highlight the therapeutic potential of clock-based pharmacological interventions for treating ischaemic heart disease.
Circadian rhythms, Cryoelectron microscopy, Myocardial infarction, Randomized controlled trials, Translational research
Quantum twisting microscopy of phonons in twisted bilayer graphene
Original Paper | Electronic properties and materials | 2025-04-22 20:00 EDT
J. Birkbeck, J. Xiao, A. Inbar, T. Taniguchi, K. Watanabe, E. Berg, L. Glazman, F. Guinea, F. von Oppen, S. Ilani
The coupling between electrons and phonons is one of the fundamental interactions in solids, underpinning a wide range of phenomena, such as resistivity, heat conductivity and superconductivity. However, direct measurements of this coupling for individual phonon modes remain a substantial challenge. In this work, we introduce a new technique for mapping phonon dispersions and electron-phonon coupling (EPC) in van der Waals (vdW) materials. By generalizing the quantum twisting microscope1 (QTM) to cryogenic temperatures, we demonstrate its capability to map not only electronic dispersions through elastic momentum-conserving tunnelling but also phononic dispersions through inelastic momentum-conserving tunnelling. Crucially, the inelastic tunnelling strength provides a direct and quantitative measure of the momentum and mode-resolved EPC. We use this technique to measure the phonon spectrum and EPC of twisted bilayer graphene (TBG) with twist angles larger than 6°. Notably, we find that, unlike standard acoustic phonons, whose coupling to electrons diminishes as their momentum tends to zero, TBG exhibits a low-energy mode whose coupling increases with decreasing twist angle. We show that this unusual coupling arises from the modulation of the interlayer tunnelling by a layer-antisymmetric ‘phason’ mode of the moiré system. The technique demonstrated here opens the way for examining a large variety of other neutral collective modes that couple to electronic tunnelling, including plasmons2, magnons3 and spinons4 in quantum materials.
Electronic properties and materials, Graphene, Scanning probe microscopy
Microbial metabolite drives ageing-related clonal haematopoiesis via ALPK1
Original Paper | Cell signalling | 2025-04-22 20:00 EDT
Puneet Agarwal, Avery Sampson, Kathleen Hueneman, Kwangmin Choi, Niels Asger Jakobsen, Emma Uible, Chiharu Ishikawa, Jennifer Yeung, Lyndsey Bolanos, Xueheng Zhao, Kenneth D. Setchell, David B. Haslam, Jessica Galloway-Pena, John C. Byrd, Paresh Vyas, Daniel T. Starczynowski
Clonal haematopoiesis of indeterminate potential (CHIP) involves the gradual expansion of mutant pre-leukaemic haematopoietic cells, which increases with age and confers a risk for multiple diseases, including leukaemia and immune-related conditions1. Although the absolute risk of leukaemic transformation in individuals with CHIP is very low, the strongest predictor of progression is the accumulation of mutant haematopoietic cells2. Despite the known associations between CHIP and increased all-cause mortality, our understanding of environmental and regulatory factors that underlie this process during ageing remains rudimentary. Here we show that intestinal alterations, which can occur with age, lead to systemic dissemination of a microbial metabolite that promotes pre-leukaemic cell expansion. Specifically, ADP-d-glycero-β-d-manno-heptose (ADP-heptose), a biosynthetic bi-product specific to Gram-negative bacteria3,4,5, is uniquely found in the circulation of older individuals and favours the expansion of pre-leukaemic cells. ADP-heptose is also associated with increased inflammation and cardiovascular risk in CHIP. Mechanistically, ADP-heptose binds to its receptor, ALPK1, triggering transcriptional reprogramming and NF-κB activation that endows pre-leukaemic cells with a competitive advantage due to excessive clonal proliferation. Collectively, we identify that the accumulation of ADP-heptose represents a direct link between ageing and expansion of rare pre-leukaemic cells, suggesting that the ADP-heptose-ALPK1 axis is a promising therapeutic target to prevent progression of CHIP to overt leukaemia and immune-related conditions.
Cell signalling, Haematological diseases
Modular chiral origami metamaterials
Original Paper | Mechanical engineering | 2025-04-22 20:00 EDT
Tuo Zhao, Xiangxin Dang, Konstantinos Manos, Shixi Zang, Jyotirmoy Mandal, Minjie Chen, Glaucio H. Paulino
Metamaterials with multimodal deformation mechanisms resemble machines1,2, especially when endowed with autonomous functionality. A representative architected assembly, with tunable chirality, converts linear motion into rotation3. These chiral metamaterials with a machine-like dual modality have potential use in areas such as wave manipulation4, optical activity related to circular polarization5 and chiral active fluids6. However, the dual motions are essentially coupled and cannot be independently controlled. Moreover, they are restricted to small deformation, that is, strain ≤2%, which limits their applications. Here we establish modular chiral metamaterials, consisting of auxetic planar tessellations and origami-inspired columnar arrays, with decoupled actuation. Under single-degree-of-freedom actuation, the assembly twists between 0° and 90°, contracts in-plane up to 25% and shrinks out-of-plane more than 50%. Using experiments and simulations, we show that the deformation of the assembly involves in-plane twist and contraction dominated by the rotating-square tessellations and out-of-plane shrinkage dominated by the tubular Kresling origami arrays. Moreover, we demonstrate two distinct actuation conditions: twist with free translation and linear displacement with free rotation. Our metamaterial is built on a highly modular assembly, which enables reprogrammable instability, local chirality control, tunable loading capacity and scalability. Our concept provides routes towards multimodal, multistable and reprogrammable machines, with applications in robotic transformers, thermoregulation, mechanical memories in hysteresis loops, non-commutative state transition and plug-and-play functional assemblies for energy absorption and information encryption.
Mechanical engineering, Mechanical properties
Melt focusing along lithosphere-asthenosphere boundary below Axial volcano
Original Paper | Geodynamics | 2025-04-22 20:00 EDT
G. M. Kent, A. F. Arnulf, S. C. Singh, H. Carton, A. J. Harding, S. Saustrup
Beneath oceanic spreading centres, the lithosphere-asthenosphere boundary (LAB) acts as a permeability barrier that focuses the delivery of melt from deep within the mantle towards the spreading axis1. At intermediate-spreading to fast-spreading ridge crests, the multichannel seismic reflection technique has imaged a nearly flat, 1-2-km-wide axial magma lens (AML)2 that defines the uppermost section of the LAB3, but the nature of the LAB deeper into the crust has been more elusive, with some clues gained from tomographic images, providing only a diffuse view of a wider halo of lower-velocity material seated just beneath the AML4. Here we present 3D seismic reflection images of the LAB extending deep (5-6 km) into the crust beneath Axial volcano, located at the intersection of the Juan de Fuca Ridge and the Cobb-Eickelberg hotspot. The 3D shape of the LAB, which is coincident with a thermally controlled magma assimilation front, focuses hotspot-related and mid-ocean-spreading-centre-related magmatism towards the centre of the volcano, controlling both eruption and hydrothermal processes and the chemical composition of erupted lavas5. In this context, the LAB can be viewed as the upper surface of a ‘magma domain’, a volume within which melt bodies reside (replacing the concept of a single ‘magma reservoir’)6. Our discovery of a funnel-shaped, crustal LAB suggests that thermally controlled magma assimilation could be occurring along this surface at other volcanic systems, such as Iceland.
Geodynamics, Natural hazards, Petrology, Seismology, Volcanology
Targeting PIKfyve-driven lipid metabolism in pancreatic cancer
Original Paper | Pancreatic cancer | 2025-04-22 20:00 EDT
Caleb Cheng, Jing Hu, Rahul Mannan, Tongchen He, Rupam Bhattacharyya, Brian Magnuson, Jasmine P. Wisniewski, Sydney Peters, Saadia A. Karim, David J. MacLean, Hüseyin Karabürk, Li Zhang, Nicholas J. Rossiter, Yang Zheng, Lanbo Xiao, Chungen Li, Dominik Awad, Somnath Mahapatra, Yi Bao, Yuping Zhang, Xuhong Cao, Zhen Wang, Rohit Mehra, Pietro Morlacchi, Vaibhav Sahai, Marina Pasca di Magliano, Yatrik M. Shah, Lois S. Weisman, Jennifer P. Morton, Ke Ding, Yuanyuan Qiao, Costas A. Lyssiotis, Arul M. Chinnaiyan
Pancreatic ductal adenocarcinoma (PDAC) subsists in a nutrient-deregulated microenvironment, making it particularly susceptible to treatments that interfere with cancer metabolism1,2. For example, PDAC uses, and is dependent on, high levels of autophagy and other lysosomal processes3,4,5. Although targeting these pathways has shown potential in preclinical studies, progress has been hampered by the difficulty in identifying and characterizing favourable targets for drug development6. Here, we characterize PIKfyve, a lipid kinase that is integral to lysosomal functioning7, as a targetable vulnerability in PDAC. Using a genetically engineered mouse model, we established that PIKfyve is essential to PDAC progression. Furthermore, through comprehensive metabolic analyses, we found that PIKfyve inhibition forces PDAC to upregulate a distinct transcriptional and metabolic program favouring de novo lipid synthesis. In PDAC, the KRAS-MAPK signalling pathway is a primary driver of de novo lipid synthesis. Accordingly, simultaneously targeting PIKfyve and KRAS-MAPK resulted in the elimination of the tumour burden in numerous preclinical human and mouse models. Taken together, these studies indicate that disrupting lipid metabolism through PIKfyve inhibition induces synthetic lethality in conjunction with KRAS-MAPK-directed therapies for PDAC.
Pancreatic cancer, Targeted therapies
Genomic and genetic insights into Mendel’s pea genes
Original Paper | Agricultural genetics | 2025-04-22 20:00 EDT
Cong Feng, Baizhi Chen, Julie Hofer, Yan Shi, Mei Jiang, Bo Song, Hong Cheng, Lu Lu, Luyao Wang, Alex Howard, Abdel Bendahmane, Anissa Fouchal, Carol Moreau, Chie Sawada, Christine LeSignor, Cuijun Zhang, Eleni Vikeli, Georgios Tsanakas, Hang Zhao, Jitender Cheema, J. Elaine Barclay, Junliang Hou, Liz Sayers, Luzie Wingen, Marielle Vigouroux, Martin Vickers, Mike Ambrose, Marion Dalmais, Paola Higuera-Poveda, Pengfeng Li, Quan Yuan, Rebecca Spanner, Richard Horler, Roland Wouters, Smitha Chundakkad, Tian Wu, Xiaoxiao Zhao, Xiuli Li, Yuchen Sun, Zejian Huang, Zhen Wu, Xing Wang Deng, Burkhard Steuernagel, Claire Domoney, Noel Ellis, Noam Chayut, Shifeng Cheng
Mendel1 studied in detail seven pairs of contrasting traits in pea (Pisum sativum), establishing the foundational principles of genetic inheritance. Here we investigate the genetic architecture that underlies these traits and uncover previously undescribed alleles for the four characterized Mendelian genes2,3,4,5,6,7, including a rare revertant of Mendel’s white-flowered a allele. Primarily, we focus on the three remaining uncharacterized traits and find that (1) an approximately 100-kb genomic deletion upstream of the Chlorophyll synthase (ChlG) gene disrupts chlorophyll biosynthesis through the generation of intergenic transcriptional fusion products, conferring the yellow pod phenotype of gp mutants; (2) a MYB gene with an upstream Ogre element insertion and a CLE peptide-encoding gene with an in-frame premature stop codon explain the v and p alleles, which disrupt secondary cell wall thickening and lignification, resulting in the parchmentless, edible-pod phenotype; and (3) a 5-bp exonic deletion in a CIK-like co-receptor kinase gene, in combination with a genetic modifier locus, is associated with the fasciated stem (fa) phenotype. Furthermore, we characterize genes and alleles associated with diverse agronomic traits, such as axil ring anthocyanin pigmentation, seed size and the ‘semi-leafless’ form. This study establishes a foundation for fundamental research, education in biology and genetics, and pea breeding practices.
Agricultural genetics, Genome-wide association studies, Natural variation in plants, Plant genetics
Human de novo mutation rates from a four-generation pedigree reference
Original Paper | DNA sequencing | 2025-04-22 20:00 EDT
David Porubsky, Harriet Dashnow, Thomas A. Sasani, Glennis A. Logsdon, Pille Hallast, Michelle D. Noyes, Zev N. Kronenberg, Tom Mokveld, Nidhi Koundinya, Cillian Nolan, Cody J. Steely, Andrea Guarracino, Egor Dolzhenko, William T. Harvey, William J. Rowell, Kirill Grigorev, Thomas J. Nicholas, Michael E. Goldberg, Keisuke K. Oshima, Jiadong Lin, Peter Ebert, W. Scott Watkins, Tiffany Y. Leung, Vincent C. T. Hanlon, Sean McGee, Brent S. Pedersen, Hannah C. Happ, Hyeonsoo Jeong, Katherine M. Munson, Kendra Hoekzema, Daniel D. Chan, Yanni Wang, Jordan Knuth, Gage H. Garcia, Cairbre Fanslow, Christine Lambert, Charles Lee, Joshua D. Smith, Shawn Levy, Christopher E. Mason, Erik Garrison, Peter M. Lansdorp, Deborah W. Neklason, Lynn B. Jorde, Aaron R. Quinlan, Michael A. Eberle, Evan E. Eichler
Understanding the human de novo mutation (DNM) rate requires complete sequence information1. Here using five complementary short-read and long-read sequencing technologies, we phased and assembled more than 95% of each diploid human genome in a four-generation, twenty-eight-member family (CEPH 1463). We estimate 98-206 DNMs per transmission, including 74.5 de novo single-nucleotide variants, 7.4 non-tandem repeat indels, 65.3 de novo indels or structural variants originating from tandem repeats, and 4.4 centromeric DNMs. Among male individuals, we find 12.4 de novo Y chromosome events per generation. Short tandem repeats and variable-number tandem repeats are the most mutable, with 32 loci exhibiting recurrent mutation through the generations. We accurately assemble 288 centromeres and six Y chromosomes across the generations and demonstrate that the DNM rate varies by an order of magnitude depending on repeat content, length and sequence identity. We show a strong paternal bias (75-81%) for all forms of germline DNM, yet we estimate that 16% of de novo single-nucleotide variants are postzygotic in origin with no paternal bias, including early germline mosaic mutations. We place all this variation in the context of a high-resolution recombination map (~3.4 kb breakpoint resolution) and find no correlation between meiotic crossover and de novo structural variants. These near-telomere-to-telomere familial genomes provide a truth set to understand the most fundamental processes underlying human genetic variation.
DNA sequencing, Genome informatics, Haplotypes, Mutation, Structural variation
A distributed coding logic for thermosensation and inflammatory pain
Original Paper | Ion channels in the nervous system | 2025-04-22 20:00 EDT
Nima Ghitani, Lars J. von Buchholtz, Donald Iain MacDonald, Melanie Falgairolle, Minh Q. Nguyen, Julia A. Licholai, Nicholas J. P. Ryba, Alexander T. Chesler
Somatosensory neurons encode detailed information about touch and temperature and are the peripheral drivers of pain1,2. Here by combining functional imaging with multiplexed in situ hybridization3, we determined how heat and mechanical stimuli are encoded across neuronal classes and how inflammation transforms this representation to induce heat hypersensitivity, mechanical allodynia and continuing pain. Our data revealed that trigeminal neurons innervating the cheek exhibited complete segregation of responses to gentle touch and heat. By contrast, heat and noxious mechanical stimuli broadly activated nociceptor classes, including cell types proposed to trigger select percepts and behaviours4,5,6. Injection of the inflammatory mediator prostaglandin E2 caused long-lasting activity and thermal sensitization in select classes of nociceptors, providing a cellular basis for continuing inflammatory pain and heat hypersensitivity. We showed that the capsaicin receptor TRPV1 (ref. 7) has a central role in heat sensitization but not in spontaneous nociceptor activity. Unexpectedly, the responses to mechanical stimuli were minimally affected by inflammation, suggesting that tactile allodynia results from the continuing firing of nociceptors coincident with touch. Indeed, we have demonstrated that nociceptor activity is both necessary and sufficient for inflammatory tactile allodynia. Together, these findings refine models of sensory coding and discrimination at the cellular and molecular levels, demonstrate that touch and temperature are broadly but differentially encoded across transcriptomically distinct populations of sensory cells and provide insight into how cellular-level responses are reshaped by inflammation to trigger diverse aspects of pain.
Ion channels in the nervous system, Pain
Spatial mapping of transcriptomic plasticity in metastatic pancreatic cancer
Original Paper | Metastasis | 2025-04-22 20:00 EDT
Guangsheng Pei, Jimin Min, Kimal I. Rajapakshe, Vittorio Branchi, Yunhe Liu, Benson Chellakkan Selvanesan, Fredrik Thege, Dorsay Sadeghian, Daiwei Zhang, Kyung Serk Cho, Yanshuo Chu, Enyu Dai, Guangchun Han, Mingyao Li, Cassian Yee, Kazuki Takahashi, Bharti Garg, Herve Tiriac, Vincent Bernard, Alexander Semaan, Jean L. Grem, Thomas C. Caffrey, Jared K. Burks, Andrew M. Lowy, Andrew J. Aguirre, Paul M. Grandgenett, Michael A. Hollingsworth, Paola A. Guerrero, Linghua Wang, Anirban Maitra
Patients with treatment-refractory pancreatic cancer often succumb to systemic metastases1,2,3; however, the transcriptomic heterogeneity that underlies therapeutic recalcitrance remains understudied, particularly in a spatial context. Here we construct high-resolution maps of lineage states, clonal architecture and the tumour microenvironment (TME) using spatially resolved transcriptomics from 55 samples of primary tumour and metastases (liver, lung and peritoneum) collected from rapid autopsies of 13 people. We observe discernible transcriptomic shifts in cancer-cell lineage states as tumours transition from primary sites to organ-specific metastases, with the most pronounced intra-patient distinctions between liver and lung. Phylogenetic trees constructed from inferred copy number variations in primary and metastatic loci in each patient highlight diverse patient-specific evolutionary trajectories and clonal dissemination. We show that multiple tumour lineage states co-exist in each tissue, including concurrent metastatic foci in the same organ. Agnostic to tissue site, lineage states correlate with distinct TME features, such as the spatial proximity of TGFB1-expressing myofibroblastic cancer-associated fibroblasts (myCAFs) to aggressive ‘basal-like’ cancer cells, but not to cells in the ‘classical’ or ‘intermediate’ states. These findings were validated through orthogonal and cross-species analyses using mouse tissues and patient-derived organoids. Notably, basal-like cancer cells aligned with myCAFs correlate with plasma-cell exclusion from the tumour milieu, and neighbouring cell analyses suggest that CXCR4-CXCL12 signalling is the underlying basis for observed immune exclusion. Collectively, our findings underscore the profound transcriptomic heterogeneity and microenvironmental dynamics that characterize treatment-refractory pancreatic cancer.
Metastasis, Pancreatic cancer, Transcriptomics
Punic people were genetically diverse with almost no Levantine ancestors
Original Paper | Anthropology | 2025-04-22 20:00 EDT
Harald Ringbauer, Ayelet Salman-Minkov, Dalit Regev, Iñigo Olalde, Tomer Peled, Luca Sineo, Gioacchino Falsone, Peter van Dommelen, Alissa Mittnik, Iosif Lazaridis, Davide Pettener, Maria Bofill, Ana Mezquida, Benjamí Costa, Helena Jiménez, Patricia Smith, Stefania Vai, Alessandra Modi, Arie Shaus, Kim Callan, Elizabeth Curtis, Aisling Kearns, Ann Marie Lawson, Matthew Mah, Adam Micco, Jonas Oppenheimer, Lijun Qiu, Kristin Stewardson, J. Noah Workman, Nicholas Márquez-Grant, Antonio M. Sáez Romero, María Luisa Lavado Florido, Juan Manuel Jiménez-Arenas, Isidro Jorge Toro Moyano, Enrique Viguera, José Suárez Padilla, Sonia López Chamizo, Tomas Marques-Bonet, Esther Lizano, Alicia Rodero Riaza, Francesca Olivieri, Pamela Toti, Valentina Giuliana, Alon Barash, Liran Carmel, Elisabetta Boaretto, Marina Faerman, Michaela Lucci, Francesco La Pastina, Alessia Nava, Francesco Genchi, Carla Del Vais, Gabriele Lauria, Francesca Meli, Paola Sconzo, Giulio Catalano, Elisabetta Cilli, Anna Chiara Fariselli, Francesco Fontani, Donata Luiselli, Brendan J. Culleton, Swapan Mallick, Nadin Rohland, Lorenzo Nigro, Alfredo Coppa, David Caramelli, Ron Pinhasi, Carles Lalueza-Fox, Ilan Gronau, David Reich
The maritime Phoenician civilization from the Levant transformed the entire Mediterranean during the first millennium bce1,2,3. However, the extent of human movement between the Levantine Phoenician homeland and Phoenician-Punic settlements in the central and western Mediterranean has been unclear in the absence of comprehensive ancient DNA studies. Here, we generated genome-wide data for 210 individuals, including 196 from 14 sites traditionally identified as Phoenician and Punic in the Levant, North Africa, Iberia, Sicily, Sardinia and Ibiza, and an early Iron Age individual from Algeria. Levantine Phoenicians made little genetic contribution to Punic settlements in the central and western Mediterranean between the sixth and second centuries bce, despite abundant archaeological evidence of cultural, historical, linguistic and religious links4. Instead, these inheritors of Levantine Phoenician culture derived most of their ancestry from a genetic profile similar to that of Sicily and the Aegean. Much of the remaining ancestry originated from North Africa, reflecting the growing influence of Carthage5. However, this was a minority contributor of ancestry in all of the sampled sites, including in Carthage itself. Different Punic sites across the central and western Mediterranean show similar patterns of high genetic diversity. We also detect genetic relationships across the Mediterranean, reflecting shared demographic processes that shaped the Punic world.
Anthropology, Archaeology, Consanguinity, Population genetics
Brief antibiotic use drives human gut bacteria towards low-cost resistance
Original Paper | Antimicrobial resistance | 2025-04-22 20:00 EDT
Eitan Yaffe, Les Dethlefsen, Arati V. Patankar, Chen Gui, Susan Holmes, David A. Relman
Understanding the relationship between antibiotic use and the evolution of antimicrobial resistance is vital for effective antibiotic stewardship. Yet, animal models and in vitro experiments poorly replicate real-world conditions1. To explain how resistance evolves in vivo, we exposed 60 human participants to ciprofloxacin and used longitudinal stool samples and a new computational method to assemble the genomes of 5,665 populations of commensal bacterial species within participants. Analysis of 2.3 million polymorphic sequence variants revealed 513 populations that underwent selective sweeps. We found convergent evolution focused on DNA gyrase and evidence of dispersed selective pressure at other genomic loci. Roughly 10% of susceptible bacterial populations evolved towards resistance through sweeps that involved substitutions at a specific amino acid in gyrase. The evolution of gyrase was associated with large populations that decreased in relative abundance during exposure. Sweeps persisted for more than 10 weeks in most cases and were not projected to revert within a year. Targeted amplification showed that gyrase mutations arose de novo within the participants and exhibited no measurable fitness cost. These findings revealed that brief ciprofloxacin exposure drives the evolution of resistance in gut commensals, with mutations persisting long after exposure. This study underscores the capacity of the human gut to promote the evolution of resistance and identifies key genomic and ecological factors that shape bacterial adaptation in vivo.
Antimicrobial resistance, Evolutionary biology, Genome assembly algorithms, Metagenomics
Structural basis of lipid transfer by a bridge-like lipid-transfer protein
Original Paper | Cryoelectron microscopy | 2025-04-22 20:00 EDT
Yunsik Kang, Katherine S. Lehmann, Hannah Long, Amanda Jefferson, Maria Purice, Marc Freeman, Sarah Clark
Bridge-like lipid-transport proteins (BLTPs) are an evolutionarily conserved family of proteins that localize to membrane-contact sites and are thought to mediate the bulk transfer of lipids from a donor membrane, typically the endoplasmic reticulum, to an acceptor membrane, such as that of the cell or an organelle1. Although BLTPs are fundamentally important for a wide array of cellular functions, their architecture, composition and lipid-transfer mechanisms remain poorly characterized. Here we present the subunit composition and the cryogenic electron microscopy structure of the native LPD-3 BLTP complex isolated from transgenic Caenorhabditis elegans. LPD-3 folds into an elongated, rod-shaped tunnel of which the interior is filled with ordered lipid molecules that are coordinated by a track of ionizable residues that line one side of the tunnel. LPD-3 forms a complex with two previously uncharacterized proteins, one of which we have named Spigot and the other of which remains unnamed. Spigot interacts with the N-terminal end of LPD-3 where lipids are expected to enter the tunnel, and experiments in multiple model systems indicate that Spigot has a conserved role in BLTP function. Our LPD-3 complex structural data reveal protein-lipid interactions that suggest a model for how the native LPD-3 complex mediates bulk lipid transport and provides a foundation for mechanistic studies of BLTPs.
Cryoelectron microscopy, Lipids, Organelles, Transport carrier
Nature Materials
Double-network-inspired mechanical metamaterials
Original Paper | Gels and hydrogels | 2025-04-22 20:00 EDT
James Utama Surjadi, Bastien F. G. Aymon, Molly Carton, Carlos M. Portela
Mechanical metamaterials can achieve high stiffness and strength at low densities, but often at the expense of low ductility and stretchability–a persistent trade-off in materials. In contrast, double-network hydrogels feature interpenetrating compliant and stiff polymer networks, and exhibit unprecedented combinations of high stiffness and stretchability, resulting in exceptional toughness. Here we present double-network-inspired metamaterials by integrating monolithic truss (stiff) and woven (compliant) components into a metamaterial architecture, which achieves a tenfold increase in stiffness and stretchability compared to its pure counterparts. Nonlinear computational mechanics models elucidate that enhanced energy dissipation in these double-network-inspired metamaterials stems from increased frictional dissipation due to entanglements between networks. Through introduction of internal defects, which typically degrade mechanical properties, we demonstrate a threefold increase in energy dissipation for these metamaterials via failure delocalization. This work opens avenues for developing metamaterials in a high-compliance regime inspired by polymer network topologies.
Gels and hydrogels, Mechanical properties
Electron ptychography reveals a ferroelectricity dominated by anion displacements
Original Paper | Ferroelectrics and multiferroics | 2025-04-22 20:00 EDT
Harikrishnan KP, Ruijuan Xu, Kinnary Patel, Kevin J. Crust, Aarushi Khandelwal, Chenyu Zhang, Sergey Prosandeev, Hua Zhou, Yu-Tsun Shao, Laurent Bellaiche, Harold Y. Hwang, David A. Muller
Sodium niobate, a lead-free ferroic material, hosts delicately balanced, competing order parameters, including ferroelectric states that can be stabilized by epitaxial strain. Here we show that the resulting macroscopic ferroelectricity exhibits an unconventional microscopic structure using multislice electron ptychography. This technique overcomes multiple scattering artefacts limiting conventional electron microscopy, enabling both lateral spatial resolution beyond the diffraction limit and recovery of three-dimensional structural information. These imaging capabilities allow us to separate the ferroelectric interior of the sample from the relaxed surface structure and identify the soft phonon mode and related structural distortions with picometre precision. Unlike conventional ferroelectric perovskites, we find that the polar distortion in this material involves minimal distortions of the cation sublattices and is instead dominated by anion displacements relative to the niobium sublattice. We establish limits on film thickness for interfacial octahedral rotation engineering and directly visualize a random octahedral rotation pattern, arising from the flat dispersion of the associated phonon mode.
Ferroelectrics and multiferroics, Surfaces, interfaces and thin films, Transmission electron microscopy
Nature Nanotechnology
An orally administered gene editing nanoparticle boosts chemo-immunotherapy in colorectal cancer
Original Paper | Biomaterials | 2025-04-22 20:00 EDT
Kai Zhao, Yu Yan, Xiao-Kang Jin, Ting Pan, Shi-Man Zhang, Chi-Hui Yang, Zhi-Yong Rao, Xian-Zheng Zhang
Chemoresistance and immunosuppression are common obstacles to the efficacy of chemo-immunotherapy in colorectal cancer (CRC) and are regulated by mitochondrial chaperone proteins. Here we show that the disruption of the tumour necrosis factor receptor-associated protein 1 (TRAP1) gene, which encodes a mitochondrial chaperone in tumour cells, causes the translocation of cyclophilin D in tumour cells. This process results in the continuous opening of the mitochondrial permeability transition pore, which enhances chemotherapy-induced cell necrosis and promotes immune responses. On the basis of this discovery we developed an oral CRISPR-Cas9 delivery system based on zwitterionic and polysaccharide polymer-coated nanocomplexes that disrupts the TRAP1 gene in CRC. This system penetrates the intestinal mucus layer and undergoes epithelial transcytosis, accumulating in CRC tissues. It enhances chemotherapeutic efficacy by overcoming chemoresistance and activating the tumour immune microenvironment in orthotopic, chemoresistant and spontaneous CRC models, with remarkable synergistic antitumour effects. This oral CRISPR-Cas9 delivery system represents a promising therapeutic strategy for the clinical management of CRC.
Biomaterials, Nanostructures
Ferumoxytol promotes haematopoietic stem cell post-injury regeneration as a reactive oxygen species scavenger
Original Paper | Biomaterials | 2025-04-22 20:00 EDT
Qiwei Wang, Wenchang Qian, Yingli Han, Yu Mao, Zhenyue Gao, Yuxuan Chen, Xin Zeng, Huan Lu, Lingli Jiang, Jinxin Li, Ning Gu, Pengxu Qian
Under stress conditions, such as ex vivo culture, chemotherapy, irradiation and infection, haematopoietic stem cells (HSCs) actively divide to maintain blood cell production. This process leads to production of reactive oxygen species (ROS) that causes HSC exhaustion and haematopoietic failure. Here we show that ferumoxytol (FMT; Feraheme), a Food and Drug Administration-approved nanodrug, is a powerful ROS scavenger capable of relieving ROS in stressed HSCs, facilitating their post-injury regeneration. Mechanistically, the catalase-like activity of FMT reduces intracellular levels of H2O2 and diminishes H2O2-induced cytotoxicity. Moreover, FMT maintains long-term regenerative capacity of transplanted HSCs in pre-conditioned leukaemic mice and shows potential to effectively eliminate leukaemia in vivo while preserving HSCs. Our study highlights FMT as a powerful clinical tool to promote haematopoietic cell recovery in patients undergoing stress-generating treatments.
Biomaterials, Tissue engineering and regenerative medicine
Ferroelectric topologies in BaTiO3 nanomembranes for light field manipulation
Original Paper | Ferroelectrics and multiferroics | 2025-04-22 20:00 EDT
Haoying Sun, Pengcheng Chen, Wei Mao, Changqing Guo, Yueying Li, Jierong Wang, Wenjie Sun, Duo Xu, Bo Hao, Tingjun Zhang, Jianan Ma, Jiangfeng Yang, Zhequan Cao, Shengjun Yan, Yuze Guan, Zonghan Wen, Zhangwen Mao, Ningchong Zheng, Zhengbin Gu, Houbing Huang, Peng Wang, Yong Zhang, Di Wu, Yuefeng Nie
Ferroelectric topological textures in oxides exhibit exotic dipole-moment configurations that would be ideal for nonlinear spatial light field manipulation. However, conventional ferroelectric polar topologies are spatially confined to the nanoscale, resulting in a substantial size mismatch with laser modes. Here we report a dome-shaped ferroelectric topology with micrometre-scale lateral dimensions using nanometre-thick freestanding BaTiO3 membranes and demonstrate its feasibility for spatial light field manipulation. The dome-shaped topology results from a radial flexoelectric field created through anisotropic lattice distortion, which, in turn, generates centre-convergent microdomains. The interaction between the continuous curling of dipoles and light promotes the conversion of circularly polarized waves into vortex light fields through nonlinear spin-to-orbit angular momentum conversion. Further dynamic manipulation of vortex light fields can also be achieved by thermal and electrical switching of the polar topology. Our work highlights the potential for other ferroelectric polar topologies in light field manipulation.
Ferroelectrics and multiferroics, Structural properties
Nature Physics
Control of spin currents by magnon interference in a canted antiferromagnet
Original Paper | Magnetic properties and materials | 2025-04-22 20:00 EDT
Lutong Sheng, Anna Duvakina, Hanchen Wang, Kei Yamamoto, Rundong Yuan, Jinlong Wang, Peng Chen, Wenqing He, Kanglin Yu, Yuelin Zhang, Jilei Chen, Junfeng Hu, Wenjie Song, Song Liu, Xiufeng Han, Dapeng Yu, Jean-Philippe Ansermet, Sadamichi Maekawa, Dirk Grundler, Haiming Yu
Controlling the spin current lies at the heart of spintronics and its applications. In ferromagnets, the sign of spin currents is fixed once the current direction is determined. However, spin currents in antiferromagnets can possess opposite polarizations, but this requires enormous magnetic fields to lift the degeneracy between the two modes. Therefore, controlling spin currents with opposite polarization is still a challenge. Here we demonstrate the control of spin currents at room temperature by magnon interference in a canted antiferromagnet, namely, haematite that has recently been classified as an altermagnet. Magneto-optical characterization by Brillouin light scattering reveals that the spatial periodicity of the beating patterns is tunable via the microwave frequency. We further observe that the inverse spin Hall voltage changes sign as the frequency is tuned, evincing a frequency-controlled switching of polarization of pure spin currents. Our work highlights the use of antiferromagnetic magnon interference to control spin currents, which substantially extends the horizon for the emerging field of coherent antiferromagnetic spintronics.
Magnetic properties and materials, Spintronics
Physical Review Letters
Quantum Many-Body Scars beyond the PXP Model in Rydberg Simulators
Research article | Eigenstate thermalization | 2025-04-22 06:00 EDT
Aron Kerschbaumer, Marko Ljubotina, Maksym Serbyn, and Jean-Yves Desaules
Persistent revivals recently observed in Rydberg atom simulators have challenged our understanding of thermalization and attracted much interest to the concept of quantum many-body scars (QMBSs). QMBSs are non-thermal highly excited eigenstates that coexist with typical eigenstates in the spectrum of many-body Hamiltonians, and have since been reported in multiple theoretical models, including the so-called PXP model, approximately realized by Rydberg simulators. At the same time, questions of how common QMBSs are and in what models they are physically realized remain open. In this Letter, we demonstrate that QMBSs exist in a broader family of models that includes and generalizes PXP to longer-range constraints and states with different periodicity. We show that in each model, multiple QMBS families can be found. Each of them relies on a different approximate $\mathfrak{su}(2)$ algebra, leading to oscillatory dynamics in all cases. However, in contrast to the PXP model, their observation requires launching dynamics from weakly entangled initial states rather than from a product state. QMBSs reported here may be experimentally probed using Rydberg atom simulator in the regime of longer-range Rydberg blockades.
Phys. Rev. Lett. 134, 160401 (2025)
Eigenstate thermalization, Quantum quench, Quantum scars, Rydberg atoms & molecules
Quantum Thermodynamics with Coherence: Covariant Gibbs-Preserving Operation Is Characterized by the Free Energy
Research article | Quantum thermodynamics | 2025-04-22 06:00 EDT
Naoto Shiraishi
The resource theory with covariant Gibbs-preserving operations, also called enhanced thermal operations, is investigated. We prove that with the help of a correlated catalyst, the state convertibility for any coherent state is fully characterized by the free energy defined with the quantum relative entropy. We can extend this result to general resource theories in the form that imposing the covariant condition to a general resource theory does not change the state convertibility, as long as the initial state is coherent and distillable and this resource theory admits the phase estimation and the phase shift. This means that adding a constraint from the law of energy conservation is irrelevant in the correlated-catalytic framework.
Phys. Rev. Lett. 134, 160402 (2025)
Quantum thermodynamics, Resource theories
Faithful Quantum Teleportation via a Nanophotonic Nonlinear Bell State Analyzer
Research article | Nonlinear optics | 2025-04-22 06:00 EDT
Joshua Akin, Yunlei Zhao, Paul G. Kwiat, Elizabeth A. Goldschmidt, and Kejie Fang
Quantum networking protocols, including quantum teleportation and entanglement swapping, use linear-optical Bell state measurements for heralding the distribution and transfer of quantum information. However, a linear-optical Bell state measurement requires identical photons and is susceptible to errors caused by multiphoton emission, fundamentally limiting the efficiency and fidelity of quantum networking protocols. Here we show a nonlinear Bell state analyzer for time-bin encoded photons based on a nanophotonic cavity with a sum-frequency generation efficiency of $4\times{}{10}^{- 5}$ to filter multiphoton emissions, and utilize it for faithful quantum teleportation involving spectrally distinct photons with fidelities $\ge 94%$ down to the single-photon level. Our result demonstrates that nonlinear-optical entangling operations, empowered by our efficient nanophotonics platform, can realize faithful quantum information protocols without requiring identical photons and without the fundamental limit on the fidelity of a Bell state measurement imposed by linear optics, which facilitates the realization of practical quantum networks.
Phys. Rev. Lett. 134, 160802 (2025)
Nonlinear optics, Quantum communication, Quantum optics, Quantum teleportation
New Probe of Cosmic Birefringence Using Galaxy Polarization and Shapes
Research article | Cosmic strings & domain walls | 2025-04-22 06:00 EDT
Weichen Winston Yin (尹維晨), Liang Dai (戴亮), Junwu Huang (黄俊午), Lingyuan Ji (吉聆远), and Simone Ferraro
We propose a novel statistical method to measure cosmic birefringence and demonstrate its power in probing parity violation due to axions. Exploiting an empirical correlation between the integrated radio polarization direction of a spiral galaxy and its apparent shape, we devise an unbiased minimum-variance estimator for the rotation angle, which should achieve an uncertainty of 5^\circ{}–15^\circ{} per galaxy. Large galaxy samples from the forthcoming SKA continuum surveys, together with optical shape catalogs, promise a comparable or even lower noise power spectrum for the rotation angle than in the CMB Stage-IV (CMB-S4) experiment, with different systematics.
Phys. Rev. Lett. 134, 161001 (2025)
Cosmic strings & domain walls, Particle astrophysics, Radio, microwave, & sub-mm astronomy, Signatures with specific particles, Axion-like particles, Normal galaxies, Electromagnetic radiation astronomy, Statistical methods
Discovering Dark Matter with the MUonE Experiment
Research article | Hypothetical particle physics models | 2025-04-22 06:00 EDT
Gordan Krnjaic, Duncan Rocha, and Isaac R. Wang
The planned MUonE experiment could–in addition to studying the muon’s magnetic moment–search for dark matter particles.
Phys. Rev. Lett. 134, 161801 (2025)
Hypothetical particle physics models, Particle detectors
Measurement of $^{6}\mathrm{H}$ Ground State Energy in an Electron Scattering Experiment at MAMI-A1
Research article | Few-body systems | 2025-04-22 06:00 EDT
Tianhao Shao et al. (A1 Collaboration)
For the first time the neutron-rich hydrogen isotope $^{6}\mathrm{H}$ was produced in an electron scattering experiment in the reaction $^{7}\mathrm{Li}(\mathrm{e},{\mathrm{e}}^{‘ }\mathrm{p}{\pi }^{+}{)}^{6}\mathrm{H}$ using the spectrometer facility of the A1 Collaboration at the Mainz Microtron accelerator. By measuring the triple coincidence between the scattered electron, the produced proton, and ${\pi }^{+}$, the missing mass spectrum of $^{6}\mathrm{H}$ was obtained. A clear peak above $^{3}\mathrm{H}+\mathrm{n}+\mathrm{n}+\mathrm{n}$ energy threshold was seen resulting in a ground state energy of $^{6}\mathrm{H}$ at $2.3\pm{}0.5(\mathrm{stat}.)\pm{}0.4(\mathrm{syst}.)\text{ }\text{ }\mathrm{MeV}$ with a width of $1.9\pm{}1.0(\mathrm{stat}.)\pm{}0.4(\mathrm{syst}.)\text{ }\text{ }\mathrm{MeV}$. This Letter challenges the understandings of multinucleon interactions and presents a new method to study light neutron-rich nuclei with electron scattering experiments.
Phys. Rev. Lett. 134, 162501 (2025)
Few-body systems, Nuclear reactions, Nuclear structure & decays, Nucleon-nucleon interactions, Rare & new isotopes
Unveiling Supersolid Order via Vortex Trajectory Correlations
Research article | Bose-Einstein condensates | 2025-04-22 06:00 EDT
Subrata Das and Vito W. Scarola
The task of experimentally investigating the inherently dual properties of a supersolid, a simultaneous superfluid and solid, has become more critical following the recent experimental exploration of supersolid regimes in dipolar Bose-Einstein condensates (BECs) of $^{164}\mathrm{Dy}$. We introduce a supersolid order parameter that uses vortex-vortex trajectory correlations to simultaneously reveal the periodic density of the underlying solid and superfluidity in a single measure. We propose experiments using existing technology to optically create and image trajectories of vortex dipoles in dipolar BECs that is applicable to large system sizes. We numerically test our observable and find that vortex-vortex correlations reveal the supersolid lattice structure while distinguishing it from superfluidity even in the presence of dissipation. Our method sets the stage for experiments to use vortex trajectory correlations to investigate fundamental properties of supersolids arising from their dynamics and phase transitions as experimental system sizes are increased.
Phys. Rev. Lett. 134, 163401 (2025)
Bose-Einstein condensates, Dipolar gases, Vortex dynamics, Superfluids, Supersolids
Probing Bulk Band Topology from Time Boundary Effect in Synthetic Dimension
Research article | Photonics | 2025-04-22 06:00 EDT
Huisheng Xu, Zhaohui Dong, Luqi Yuan, and Liang Jin
An incident wave at a temporal interface, created by an abrupt change in system parameters, generates time-refracted and time-reflected waves. We find topological characteristics associated with the temporal interface that separates distinct spatial topologies and report a novel bulk-boundary correspondence for the temporal interface. The vanishing of either time refraction or time reflection records a topological phase transition across the temporal interface, and the difference of bulk band topology predicts nontrivial braiding hidden in the time refraction and time reflection coefficients. These findings, which are insensitive to spatial boundary conditions and robust against disorder, are demonstrated in a synthetic frequency lattice with rich topological phases engendered by long-range couplings. Our work reveals the topological aspect of temporal interface and paves the way for using the time boundary effect to probe topological phase transitions and topological invariants.
Phys. Rev. Lett. 134, 163801 (2025)
Photonics, Topological effects in photonic systems, Topological phase transition, Nonequilibrium systems
Refractive Contribution to the Mass of an Elementary Excitation in a Dilute Bose-Einstein Condensate
Research article | Hard-core bosons | 2025-04-22 06:00 EDT
S. V. Andreev
Since the pioneering works of Landau and Feynman, the origin of a roton minimum in the excitation spectrum of a quantum Bose liquid has been debated. A consensus has been reached on relation of the roton to eventual solidification, but this viewpoint still remains to be connected to the polaronic concept of an impurity pushing through a dense medium. The diagrammatic theory allows one to approach the problem qualitatively from a dilute limit. We revisit the equation for the elementary excitation spectrum obtained in the ladder approximation and argue that polaronic renormalization of the quasiparticle mass has a contribution due to matter-wave refraction. At low energies attenuation of the quasiparticle wave turns out to be dramatically suppressed by the condensate. Refractive correction to the mass is enhanced by Bose statistics at high momenta and produces autolocalization of an elementary excitation upon increasing the density.
Phys. Rev. Lett. 134, 166001 (2025)
Hard-core bosons, Quantum fluids & solids, Quasiparticles & collective excitations
Negative Gradient Energy Facilitates Charged Domain Walls in ${\mathrm{HfO}}_{2}$
Research article | Defects | 2025-04-22 06:00 EDT
Pawan Kumar, Dipti Gupta, and Jun Hee Lee
Charged domain walls (CDWs) in ferroelectrics are often characterized as excited states, even after full bound charge compensation at domain walls (DWs). Here, we propose a mechanism where negative gradient energy (${E}{\mathrm{grad}}$) counteracts the large positive electrostatic energy (${E}{\mathrm{el}}$) induced by bound charge at DWs, stabilizing the CDWs over the bulk state, even with partial or no bound charge compensation. As proof of scheme, we demonstrate that negative ${E}{\mathrm{grad}}$ of modes, which reverse their sign during the formation of CDWs in ${\mathrm{HfO}}{2}$, partially offsets ${E}{\mathrm{el}}$. Their corresponding remaining ${E}{\mathrm{el}}$ can be neutralized by partial bound charge compensation. Exceeding this partial compensation, achieved through the substitution of ${\mathrm{Nb}}^{5+}$ at tail-to-tail and ${\mathrm{Y}}^{3+}$ at head-to-head DWs for ${\mathrm{Hf}}^{4+}$, CDWs exhibit unprecedented stability over the bulk state. The 1.33 eV band gap of the most stable CDW is particularly suitable for photovoltaic applications due to their potential for efficient electron-hole separation. We further reveal that negative phonon band curvatures are useful descriptors to uncover the origin of negative ${E}{\mathrm{grad}}$ in such CDWs, which can be estimated simply by phonon band fitting, making our scheme easy to implement for realizing CDWs beyond ${\mathrm{HfO}}{2}$.
Phys. Rev. Lett. 134, 166101 (2025)
Defects, Density of states, Domains, Doping effects, Electric polarization, Electrical properties, Electronic structure, Ferroelectricity, First-principles calculations, Lattice dynamics, Phonons
Full-Scaling Friction and Wear Laws of Nanotwinned Metals
Research article | Friction | 2025-04-22 06:00 EDT
Yan Lin, Ziyue Zhang, Fenghui Duan, Fangming Wang, Fei Liang, Qicheng Zhang, Yong Li, Jie Pan, Keke Chang, Yonghao Zhao, Yuntian Zhu, and Xiang Chen
Ultrastrong nanotwinned (NT) metals hold promise for mitigating friction and wear—essential for enhancing the energy efficiency and longevity of all moving systems. However, optimizing their tribological performance has long suffered from the absence of friction and wear laws across varying tribological loading scales. Here, we have discovered full-scaling twin lamella spacing ($\lambda $)-dependent friction and wear laws in NT pure nickel and identified critical deformation mechanisms for reducing friction and wear. Nanoscale friction initially increases with decreasing $\lambda $, peaking at 20 nm, and then decreases due to a transition from dislocation-twin boundary interactions to detwinning. Under microscale loading, friction and wear reduce linearly with decreasing $\lambda $, attributed to an unforeseen phase transition from face-centered cubic to hexagonal close-packed structures. Furthermore, under macroscale loading, the formation of a durable oxide layer and a stable gradient nanostructure in nanotwinned nickel with $\lambda $ exceeding 20 nm aids in mitigating wear loss.
Phys. Rev. Lett. 134, 166201 (2025)
Friction, Mechanical deformation, Tribology, Wear, Metals, Polycrystalline materials, Electron microscopy, Molecular dynamics
Hindered Stokesian Settling of Discs and Rods
Research article | Fluid-particle interactions | 2025-04-22 06:00 EDT
Yating Zhang and Narayanan Menon
We report measurements of the mean settling velocities for suspensions of discs and rods in the Stokes regime for a number of particle aspect ratios. All these shapes display ‘’hindered settling,’’ namely, a decrease in settling speed as the solid volume fraction is increased. A comparison of our data to spheres reveals that discs and rods show less hindering than spheres at the same relative interparticle separation. The data for all six of our particle shapes may be scaled to collapse on that of spheres, with a scaling factor that depends only on the volume of the particle relative to a sphere. Despite the orientational degrees of freedom available with nonspherical particles, it thus appears that the dominant contribution to the hindered settling emerges from terms that are simply proportional to the volume of the sedimenting particles, enabling prediction of hindered settling of other nonpolar axisymmetric shapes.
Phys. Rev. Lett. 134, 168202 (2025)
Fluid-particle interactions
Physical Review X
Probing Many-Body Bell Correlation Depth with Superconducting Qubits
Research article | Nonlocality | 2025-04-22 06:00 EDT
Ke Wang et al.
*et al.*A demonstration of Bell-operator correlations in a 73-qubit quantum processor provides a benchmark for studying quantum nonlocality in complex systems that goes beyond standard measurements of entanglement.
Phys. Rev. X 15, 021024 (2025)
Nonlocality, Quantum information with solid state qubits
arXiv
Interacting Chern insulator transition on the sphere: revealing the Gross-Neveu-Yukawa criticality
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-23 20:00 EDT
Zhi-Qiang Gao, Taige Wang, Dung-Hai Lee
In two spatial dimensions, the transition between topological and trivial Chern insulators exemplifies a class of beyond-Landau critical phenomena. We show that the interaction-driven multicritical point of this transition falls into the Gross-Neveu-Yukawa (GNY) universality class, a topic of considerable interest in both high-energy and condensed matter physics. In this work, we focus on the $ N=2$ case of the GNY criticality. We employ exact diagonalization of Dirac fermions on a sphere to circumvent the parity anomaly, capitalize on full SO(3) symmetry to reduce finite-size effects, and directly extract operator scaling dimensions from the excitation spectrum. Despite working with only modest system sizes, our results closely match conformal bootstrap predictions for low scaling dimension operators and reveal several previously uncharacterized higher primaries. These findings highlight the efficacy of spherical geometry for probing interacting Dirac criticality.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th)
5+10 pages, 3 figures
Multimagnon and multispinon $L_3$-edge RIXS spectra of an effective $\tilde{J}_1-\tilde{J}_2-\tilde{J}_3$ square lattice Heisenberg model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-23 20:00 EDT
Kai-Yuan Qi, Shangjian Jin, Trinanjan Datta, Dao-Xin Yao
We investigate the multimagnon and the multispinon $ L_3$ -edge resonant inelastic x-ray scattering (RIXS) spectra of a spin-1/2 effective $ \tilde{J}_1-\tilde{J}_2-\tilde{J}_3$ square lattice Heisenberg model in its Néel ordered phase. Motivated by the observation of satellite intensity peaks above the single magnon dispersion in the $ L$ -edge RIXS spectrum, we propose a resonating valence bond (RVB) inspired RIXS mechanism that incorporates the local site ultrashort core-hole lifetime (UCL) expansion. We compute the multimagnon and the multispinon excitations using $ \mathcal{O}(1/S)$ interacting spin wave theory and Schwinger boson mean-field theory (SBMFT) formalism, respectively. We treat the x-ray scattering process up to second order in the UCL expansion. Our calculations of two-magnon, bimagnon, and three-magnon RIXS intensities reveal that interacting spin wave theory fails to fully capture all the quantum correlations in the antiferromagnetic ordered phase. However utilizing the SBMFT framework, with a ground state that combines Néel order and fluctuating RVB components, we demonstrate that a RIXS bond-flipping mechanism provides an alternative deeper physical explanation of the satellite intensities. Specifically, we find that the spin correlation spectra predicted by the fluctuating RVB mechanism aligns with higher order UCL expansion results. We further show that the satellite intensity above the single-magnon mode can originate both from a one-to-three-magnon hybridization vertex process and from condensed spinons exhibiting Higgs mechanism. These features reflect the interplay of quantum fluctuation, entanglement, and gauge interaction effects of quantum magnetism probed by RIXS.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
23 pages, 10 figures
Bacterial chemotaxis considering memory effects (letter)
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-23 20:00 EDT
Chemotaxis in bacteria such as \textit{E.\ coli} is controlled by the slow methylation of chemoreceptors. As a consequence, intrinsic time and length scales of tens of seconds and hundreds of micrometers emerge, making the Keller–Segel equations invalid when the chemical signal changes on these scales, as occurs in several natural environments. Using a kinetic approach, we show that chemotaxis is described using the concentration field of the protein that controls tumbling in addition to bacterial density. The macroscopic equations for these fields are derived, which describe the nonlocal response.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
Bacterial chemotaxis considering memory effects
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-23 20:00 EDT
Bacterial chemotaxis for this http URL is controlled by methylation of chemoreceptors, which in a biochemical pathway regulates the concentration of the CheY-P protein that finally controls the tumbling rate. As a consequence, the tumbling rate adjusts to changes in the concentration of relevant chemicals, to produce a biased random walk toward chemoattractants of against the repellers. Methylation is a slow process, implying that the internal concentration of CheY-P is not instantaneously adapted to the environment, and the tumbling rate presents memory. This implies that the Keller-Segel (KS) equations used to describe chemotaxis at the macroscopic scale, which assume a local relation between the bacterial flux and the chemical gradient, are not fully valid as memory and the associated nonlocal response are not considered. To derive the equations that replace the KS ones, we use a kinetic approach, in which a kinetic equation for the bacterial transport is written considering the dynamics of the protein concentration. When memory is large, the protein concentration field must be considered a relevant variable as the bacterial density. Working out the Chapman-Enskog (CE) method, the dynamical equations for these fields are obtained, which have the form of reaction-diffusion equations with flux and source terms depending on the gradients on the chemical signal. The transport coefficients are obtained entirely in terms of the microscopic dynamics, giving their values of the case of this http URL. Solving the equations for an inhomogeneous signal it is shown that the response is nonlocal, with a smoothing length as large as $ 170\mu$ m for this http URL. The homogeneous response and the relaxational dynamics are also studied. The case of small memory is also studied, in which case the CE method reproduces the KS equations, with explicit expressions for the transport coefficients.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
Controlling the rate of resonant tunneling between quantum wells by relocating the wave function within a quantum well
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-23 20:00 EDT
The possibility of controlling the tunneling time between quantum wells by relocation of the subband wave function within the quantum well by varying the configuration of thin tunnel-transparent barriers embedded into the well is demonstrated.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 3 figures
Helicons in multi-Weyl semimetals
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-23 20:00 EDT
Helicons are transverse electromagnetic modes in three dimension(3D) electron systems in the presence of a static magnetic field. This modes have been proposed in isotropic or single Weyl semimetals(sWSMs) (Francesco M.D. Pellegrino et al, Phys. Rev. B 92, 201407(R) (2015)). In this work, we extend our study to investigate helicons modes in gapless multi-Weyl semimetals(mWSMs) within semiclassical Boltzmann approach and discuss the differences that arise compared to single Weyl semimetals.
Strongly Correlated Electrons (cond-mat.str-el), Other Condensed Matter (cond-mat.other)
Strain engineering of doped hydrogen passivated silicon quantum dots
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Swarnava Ghosh, Markus Eisenbach
Silicon quantum dots are nanomaterials that are attractive candidates for photovoltaic applications. Doping of these materials creates p-n junctions and is important for solar cells. In this work, we present a first-principles study of the coupled influence of doping and strain on the stability, energy gap, Fermi level, electronic density, and density of states of hydrogen-passivated silicon quantum dots. We find that the cohesive energy and the energy gap decrease with increasing quantum dot size and are strongly influenced by strain. Furthermore, the response to strain also depends on the size of the quantum dot and dopant type. We present expressions of cohesive energy and energy gap as power-law of size and polynomial dependence on strain. We also show that the Fermi energy increases with size for pristine and p-type doping but decreases with size for n-type doping. We also discuss the influence of strain and dopant type on the density of states and electron density of the quantum dots.
Materials Science (cond-mat.mtrl-sci)
Electronic dimensionality of UTe2
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-23 20:00 EDT
L. Zhang, C. Guo, D. Graf, C. Putzke, M. M. Bordelon, E. D. Bauer, S. M. Thomas, F. Ronning, P. F. S. Rosa, P. J. W. Moll
Superconductivity in the heavy-fermion metal UTe2 survives the application of very high magnetic fields, presenting both an intriguing puzzle and an experimental challenge. The strong, non-perturbative influence of the magnetic field complicates the determination of superconducting order parameters in the high-field phases. Here, we report electronic transport anisotropy measurements in precisely aligned microbars in magnetic fields to 45 T applied along the b-axis. Our results reveal a highly directional vortex pinning force in the field-reinforced phase. The critical current is significantly suppressed for currents along the c direction, whereas the flux-flow voltage is reduced with slight angular misalignments–hallmarks of vortex lock-in transitions typically seen in quasi-2D superconductors like cuprates and pnictides. These findings challenge the assumption of nearly isotropic charge transport in UTe2 and point to enhanced two-dimensionality in the high-field state, consistent with a change in the order parameter. A pair-density-wave-like state at high fields could naturally induce a layered modulation of the superfluid density, forming planar structures that confine vortices and guide their sliding in the flux-flow regime.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Nernst power factor and figure of merit in compensated semimetal ScSb
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Antu Laha, Sarah Paone, Asish K. Kundu, Juntao Yao, Niraj Aryal, Elio Vescovo, Qiang Li
Recently, topological semimetals have emerged as strong candidates for solid state thermomagnetic refrigerators due to their enhanced Nernst effect. This enhancement arises from the combined contributions of the Berry curvature induced anomalous Nernst coefficient associated with topological bands and the normal Nernst effect resulting from synergistic electron-hole compensation. Generally, these two effects are intertwined in topological semimetals, making it challenging to evaluate them independently. Here, we report the observation of high Nernst effect in the electron hole compensated semimetal ScSb with topologically trivial electronic band structures. Remarkably, we find a high maximum Nernst power factor of $ PF_N \sim 35 \times 10^{-4}$ W m$ ^{-1}$ K$ ^{-2}$ in ScSb. The Nernst thermopower ($ S_{xy}$ ) exhibits a peak of $ \sim$ 47 $ \mu$ V/K at 12 K and 14 T, yielding a Nernst figure of merit ($ z_N$ ) of $ \sim 28 \times 10^{-4}$ K$ ^{-1}$ . Notably, despite its trivial electronic band structure, both the $ PF_N$ and $ z_N$ values of ScSb are comparable to those observed in topological semimetals with Dirac band dispersions. The origin of the large Nernst signal in ScSb is explained by well compensated electron and hole carriers, through Hall resistivity measurements, angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) calculations.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
The case of the missing gallium vacancy in gallium arsenide: A multiscale explanation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Leopoldo Diaz, Harold P. Hjalmarson, Jesse J. Lutz, Peter A. Schultz
Irradiation of gallium arsenide (GaAs) produces immobile vacancies and mobile interstitials. However, after decades of experimental investigation, the immobile Ga vacancy eludes observation, raising the question: Where is the Ga vacancy? Static first-principles calculations predict a Ga vacancy should be readily observed. We find that short-time dynamical evolution of primary defects is key to explaining this conundrum. Introducing a multiscale Atomistically Informed Device Engineering (AIDE) method, we discover that during the initial displacement damage, the Fermi level shifts to mid-gap producing oppositely charged vacancies and interstitials. Driven by Coulomb attraction, fast As interstitials preferentially annihilate Ga vacancies, causing their population to plummet below detectable limits before being experimentally observed. This innovative model solves the mystery of the missing Ga vacancy and reveals the importance of a multiscale approach to explore the dynamical chemical behavior in experimentally inaccessible short-time regimes.
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Nonreciprocal wave-mediated interactions power a classical time crystal
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-23 20:00 EDT
Mia C. Morrell, Leela Elliott, David G. Grier
An acoustic standing wave acts as a lattice of evenly spaced potential energy wells for sub-wavelength-scale objects. Trapped particles interact with each other by exchanging waves that they scatter from the standing wave. Unless the particles have identical scattering properties, their wave-mediated interactions are nonreciprocal. Pairs of particles can use this nonreciprocity to harvest energy from the wave to sustain steady-state oscillations despite viscous drag and the absence of periodic driving. We show in theory and experiment that a minimal system composed of two acoustically levitated particles can access five distinct dynamical states, two of which are emergently active steady states. Under some circumstances, these emergently active steady states break spatiotemporal symmetry and therefore constitute a classical time crystal.
Soft Condensed Matter (cond-mat.soft)
6 pages, 3 figures
Orientation-Adaptive Virtual Imaging of Defects using EBSD
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Nicolò M. della Ventura, James D. Lamb, William C. Lenthe, McLean P. Echlin, Julia T. Pürstl, Emily S. Trageser, Alejandro M. Quevedo, Matthew R. Begley, Tresa M. Pollock, Daniel S. Gianola, Marc De Graef
EBSD is a foundational technique for characterizing crystallographic orientation, phase distribution, and lattice strain. Embedded within EBSD patterns lies latent information on dislocation structures, subtly encoded due to their deviation from perfect crystallinity - a feature often underutilized. Here, a novel framework termed orientation-adaptive virtual apertures (OAVA) is introduced. OAVAs enable the generation of virtual images tied to specific diffraction conditions, allowing the direct visualization of individual dislocations from a single EBSD map. By dynamically aligning virtual apertures in reciprocal space with the local crystallographic orientation, the method enhances contrast from defect-related strain fields, mirroring the principles of diffraction-contrast imaging in TEM, but without sample tilting. The approach capitalizes on the extensive diffraction space captured in a single high-quality EBSD scan, with its effectiveness enhanced by modern direct electron detectors that offer high-sensitivity at low accelerating voltages, reducing interaction volume and improving spatial resolution. We demonstrate that using OAVAs, identical imaging conditions can be applied across a polycrystalline field-of-view, enabling uniform contrast in differently oriented grains. Furthermore, in single-crystal GaN, threading dislocations are consistently resolved. Algorithms for the automated detection of dislocation contrast are presented, advancing defect characterization. By using OAVAs across a wide range of diffraction conditions in GaN, the visibility/invisibility of defects, owing to the anisotropy of the elastic strain field, is assessed and linked to candidate Burgers vectors. Altogether, OAVA offers a new and high-throughput pathway for orientation-specific defect characterization with the potential for automated, large-area defect analysis in single and polycrystalline materials.
Materials Science (cond-mat.mtrl-sci)
Affiliations: University of California Santa Barbara, Gatan + EDAX Inc., Carnegie Mellon University
Transition from positive to negative photoconductivity in AlGaN/GaN quantum-well heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Maciej Matys, Atsushi Yamada, Toshihiro Ohki, Kouji Tsunoda
The AlGaN/GaN quantum-well heterostructures typically exhibit a positive photoconductivity (PPC) during the light illumination. Surprisingly, we found that introducing the GaN/AlN superlattice (SL) back barrier into N-polar AlGaN/GaN quantum-well heterostructures induces a transition in these heterostructures from PPC to negativie photoconductivity (NPC) as the SL period number increased at room temperature. This transition occurred under an infrared light illumination and can be well explained in terms of the excitation of hot electrons from the two-dimensional electron gas and subsequent trapping them in a SL structure. The NPC effect observed in N-polar AlGaN/GaN heterostructures with SL back barrier exhibits photoconductivity yield exceeding 85 % and thus is the largest ones reported so far for semiconductors. In addition, NPC signal remains relatively stable at high temperatures up to 400 K. The obtained results can be interesting for the development of NPC related devices such as photoelectric logic gates, photoelectronic memory and infrared photodetectors.
Materials Science (cond-mat.mtrl-sci)
Evidence of Ultrashort Orbital Transport in Heavy Metals Revealed by Terahertz Emission Spectroscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Tongyang Guan, Jiahao Liu, Wentao Qin, Yongwei Cui, Shunjia Wang, Yizheng Wu, Zhensheng Tao
The orbital angular momentum of electrons offers a promising, yet largely unexplored, degree of freedom for ultrafast, energy-efficient information processing. As the foundation of orbitronics, understanding how orbital currents propagate and convert into charge currents is essential - but remains elusive due to the challenge in disentangling orbital and spin dynamics in ultrathin films. Although orbital currents have been predicted to propagate over long distances in materials, recent theoretical studies argue that lattice symmetry may constrain their mean free paths (MFPs) to the scale of a single atomic layer. In this work, we provide the first direct experimental evidence for ultrashort orbital MFPs in heavy metals (HMs) - W, Ta, Pt - revealed by femtosecond terahertz emission spectroscopy. This is enabled by sub-nanometer-precision control of thin-film thickness using wedge-shaped HM|Ni heterostructures. By employing a multi-component terahertz-emission model, we quantitatively extract the orbital MFPs, consistently finding them shorter than their spin counterparts. Furthermore, control experiments rule out interfacial orbital-to-charge conversion as the dominant mechanism, confirming that the process is governed by the bulk inverse orbital Hall effect. Our findings resolve a central controversy in orbitronics and provide key insights into orbital transport and conversion mechanisms.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
Designing Optimal Distorted-Octahedra Superlattices for Strong Topological Hall Effect
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Yiyan Fan, Qinghua Zhang, Jingdi Lu, Chuanrui Huo, Tianyang Wang, Qiao Jin, Ting Cui, Qianying Wang, Dongke Rong, Shiqing Deng, Lingfei Wang, Kuijuan Jin, Jun Chen, Er-Jia Guo
Topologically protected spin states hold great promise for applications in next generation of memory circuits and spintronic devices. These intriguing textures typically emerge in bulk materials or heterostructures with broken inversion symmetry, accompanied by an enhanced Dzyaloshinskii-Moriya interaction (DMI). In this study, we successfully induced the topological Hall effect (THE) in atomically designed (DyScO3)n/(SrRuO3)n (DnSn) superlattices over a significant range of temperatures (10120K) and thicknesses (1640nm). Using magnetic force microscopy (MFM), we observed the formation and stability of magnetic domains, such as topological skyrmions. By precisely controlling the interlayer thickness (n) and biaxial strain, we elucidated the mechanisms underlying the modulation and induction of magnetic topological states. Supporting evidence was provided by scanning transmission electron microscopy (STEM) and X-ray absorption spectroscopy (XAS), thereby lending further credence to our conclusions. These heterostructures offer a universal method for exploring topological phenomena driven by distorted octahedra, while enhancing the integrability and addressability of topologically protected functional devices.
Materials Science (cond-mat.mtrl-sci)
Optical-vortex-pulse induced nonequilibrium spin textures in spin-orbit coupled electrons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-23 20:00 EDT
Shunki Yamamoto, Masahiro Sato, Satoshi Fujimoto, Takeshi Mizushima
Optical vortex beams are a type of topological light characterized by their inherent orbital angular momentum, leading to the propagation of a spiral-shaped wavefront. In this study, we focus on two-dimensional electrons with Rashba and Dresselhaus spin-orbit interactions and examine how they respond to pulsed vortex beams in the terahertz frequency band. Spin-orbital interactions play a vital role in transferring the orbital angular momentum of light to electron systems and generating spatiotemporal spin textures. We show that the spatiotemporal spin polarization of electrons reflects orbital angular momentum carried by optical vortex pulses. These findings demonstrate how optical vortices facilitate ultrafast spin manipulation in spin-orbit-coupled electrons. Our results can be straightforwardly extended to the case of higher-frequency vortex beams for other two-dimensional metals with a larger Fermi energy.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 7 figures
Spin-dependent electronic transport in NiMnSb/MoS2(001)/NiMnSb magnetic tunnel junction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Aloka Ranjan Sahoo, Sharat Chandra
Half-metallic Heusler alloy compounds with Curie temperatures above room temperature are suitable candidate electrode materials for injecting large spin-polarised charge carriers into the semiconducting barriers at the ferromagnet semiconductor junction to obtain highly spin-polarised current. Combining the density functional theory and non-equilibrium Green’s function method, the electronic structure, spin dependent electron transport in NiMnSb/MoS2(001)/NiMnSb is studied. The possibilities of injecting 100% spin-polarised electron into MoS2 using half metallic NiMnSb as an electrode, the layer dependent, and the effect of the type of interface on electronic structure and spin-transport properties in magnetic tunnel junction devices are studied. We show that the half-metallicity of NiMnSb(111) is preserved at the interface between the half-Heusler alloy NiMnSb and MoS2. NiMnSb keeps a fully spin-polarised state in the majority spin channel at the interface between NiMnSb and MoS2, injecting fully spin-polarised electrons into the semiconductor. The device based on NiMnSb/MoS2(single layer)/NiMnSb has a metallic interface. Metal-induced states in the spin-majority channel of MoS2 are seen after making an interface with half metallic NiMnSb. In contrast, the NiMnSb/MoS2(three layers)/NiMnSb interface with a multilayer of MoS2 has a band gap region, and electrons can tunnel through the junction. The Mn-S interface is more conducting than the Sb-S interface due to the strong bonding of Mn and S atoms at the Mn-S interface.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
38 pages, 30 figures, 1 table
Can we build a transistor using vacancy-induced bound states in a topological insulator
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-23 20:00 EDT
Topological insulators (TIs) have been considered as promising candidates for next generation of electronic devices due to their topologically protected quantum transport phenomena. In this work, a scheme for atomic-scale field effect transistor (FET) based on vacancy-induced edge states in TIs is promoted. By designing the positions of vacancies, the closed channel between source and drain terminals provided by vacancy-induced edge states can have the energy spectra with a gap between edge and bulk states. When gate terminal receive the signal, electric field applied by gate terminal can shift quasi Fermi energy of the closed channel from edge states into the gap, and hence open the channel between source and drain terminals. The energy spectra and the effect of electric field are demonstrated using Haldane model and density functional theory (DFT) respectively. This work suggest possible revolutionary applicational potentials of vacancy-induced edge states in topological insulators for atomic-scale electronics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
5 pages, 4 figures
A diagrammatic approach to correlation functions in superfluids
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-23 20:00 EDT
Alessia Biondi, Maria Luisa Chiofalo, Massimo Mannarelli, Silvia Trabucco
Renaud Parentani has given a vast contribution to the development of gravitational analogue models as tools to explore various important aspects of general relativity and of quantum field theory in curved space-time. In these systems, two-point correlation functions are of the utmost importance for the characterization of processes taking place close to the acoustic horizon. In the present paper, dedicated to him, we present a study of path integral methods that allow to determine two-point correlation functions by a perturbative expansion, in a way that – beyond its generality – is especially suited to analyze these processes. Our results apply to non-relativistic superfluids, realizable in terrestrial experiments, as well as to relativistic superfluids, relevant for compact stellar objects.
Quantum Gases (cond-mat.quant-gas), High Energy Physics - Phenomenology (hep-ph)
16 pages, 2 figures
Designing cobalt-free face-centered cubic high-entropy alloys: A strategy using d-orbital energy level
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Yulin Li, Artur Olejarz, Lukasz Kurpaska, Eryang Lu, Mikko J. Alava, Hyoung Seop Kim, Wenyi Huo
High-entropy alloys (HEAs) are promising materials for high-temperature structural applications such as nuclear reactors due to their outstanding mechanical properties and thermal stability. Instead of the trial-and-error method, it is efficient to design and prepare single-phase face-centered cubic (FCC) structured HEAs using semi-empirical phase formation rules. However, almost all of phase formation rules were proposed without taking into account the cobalt-free situation. The HEAs containing cobalt are unsuitable for nuclear applications because of the long-term activation of cobalt. Here, six parameters, d-orbital energy level, valance electron concentration, entropy of mixing, enthalpy of mixing, atom size differences, and parameter of the entropy of mixing ({\Omega}) were calculated to determine the solid solution phase, especially the FCC phase formation rules in cobalt-free HEAs. HEAs of 4 components were arc melted to verify the newly developed phase formation rules. The nanomechanical properties of produced HEAs were evaluated using nanoindentation. Among the six parameters, the d-orbital energy level and valance electron concentration are the critical factors that determine the FCC phase stability in cobalt-free alloys. Interestingly, the d-orbital energy level can be alone used as a benchmark for developing mechanical properties.
Materials Science (cond-mat.mtrl-sci)
Accepted Version
International Journal of Refractory Metals and Hard Materials 124 (2024) 106834
Emergent epithelial elasticity governed by interfacial surface mechanics and substrate interaction
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-23 20:00 EDT
During the life of animals, epithelial tissues undergo extensive deformations–first to form organs during embryogensis and later to preserve integrity and function in adulthood. To what extent these deformations resemble that of non-living elastic materials is not well understood. We derive an elasticity theory of epithelia, supported by a thin layer of extracellular material and the stroma, in which the mechanics of individual cells are dominated by differential interfacial tensions stemming from cell cortical tension and adhesion. Upon coarse-graining a discrete single-cell-level mechanics model, we obtain a harmonic deformation energy and derive the critical conditions for the elastic instability, where an initially flat tissue either buckles out of plane or forms wrinkles. Due to the distinct origin of elasticity, the scaling of the critical load to induce an instability and the wrinkling wavelength with layer thickness is fundamentally different than in solid plates. The theory also naturally describes reversal of the groove-to-crest thickness-modulation phase–a recently observed epithelial shape feature which cannot be explained by the classical elasticity theory. Our work provides a guideline for understanding the relative role of cell surface tensions and the interaction of tissues with substrates during epithelial morphogenesis.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph)
Original mechanism of transformation from soft metallic (sp2/sp3) C12 to ultra-dense and ultra-hard (sp3) semi-conducting C12: Crystal chemistry and DFT characterizations
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
An original mechanism is proposed for a pressure-induced transformation of orthorhombic C12 from ground state normal pressure (NP) sp2/sp3 allotrope to ultra-dense and ultra-hard HP sp3 form. Upon volume decrease, the trigonal C=C parallel segments characterizing glitter-like tfi topology of NP C12 change to crossing C-C segments with the loss of sp2 character accompanied by a large densification with density=3.64 g/cm3, larger than diamond, defining a novel orthorhombic HP C12 with 44T39 topology. The crystal chemistry engineering backed with quantum density functional theory DFT-based calculations let determine the ground state structures and energy derived physical properties. Furthering on that, the E(V) equations of states (EOS) let define the equilibrium NP(E0,V0) allotrope at lower energy and higher volume versus HP(E0, V0) allotrope at higher energy and smaller volume. A potential pressure induced transformation NP to HP was estimated at ~100 GPa, reachable with a diamond anvil cell DAC. Both allotropes were found cohesive and mechanically stable with low and large Vickers hardness magnitudes: HV(tfi C12) =24 GPa and HV(44T39 C12) =90 GPa; the latter being close to diamond hardness (HV ~95 GPa). Besides, both allotropes were found dynamically stable with positive phonon frequencies and a spectroscopic signature of C=C high frequency bands in tfi C12. The electronic band structures show metallic behavior for NP tfi C12 and a small band gap for HP 44T39 C12 letting assign semiconducting properties. The work is meant to open further the scope of C(sp2)and C(sp3) transformation mechanisms that are fundamental in solid state physics and chemistry.
Materials Science (cond-mat.mtrl-sci)
17 page, 6 Figures, 2 Tables
Spin and energy diffusion vs. subdiffusion in disordered spin chains
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-23 20:00 EDT
While the high-temperature spin diffusion in spin chains with random local fields has been the subject of numerous studies concerning the phenomenon of many-body localization (MBL), the energy diffusion in the same models has been much less explored. We show that energy diffusion is faster at weak random fields but becomes essentially equal at strong fields; hence, both diffusions determine the slowest relaxation time scale (Thouless time) in the system. Numerically reachable finite-size systems reveal the anomalously large distribution of diffusion constants with respect to actual field configurations. Despite the exponential-like dependence of diffusion on field strength, results for the sensitivity to twisted boundary conditions are incompatible with the Thouless criterion for localization and the presumable transition to MBL, at least for numerically reachable sizes. In contrast, we find indications for the scenario of subdiffusive transport, in particular in the dynamical diffusivity response.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Strongly Correlated Electrons (cond-mat.str-el)
Domain-wall driven suppression of thermal conductivity in a ferroelectric polycrystal
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Rachid Belrhiti-Nejjar, Manuel Zahn, Patrice Limelette, Max Haas, Lucile Féger, Isabelle Monot-Laffez, Nicolas Horny, Dennis Meier, Fabien Giovannelli, Jan Schultheiß, Guillaume F. Nataf
A common strategy for reducing thermal conductivity of polycrystalline systems is to increase the number of grain boundaries. Indeed, grain boundaries enhance the probability of phonon scattering events, which has been applied to control the thermal transport in a wide range of materials, including hard metals, diamond, oxides and 2D systems such as graphene. Here, we report the opposite behavior in improper ferroelectric ErMnO3 polycrystals, where the thermal conductivity decreases with increasing grain size. We attribute this unusual relationship between heat transport and microstructure to phonon scattering at ferroelectric domain walls. The domain walls are more densely packed in larger grains, leading to an inversion of the classical grain-boundary-dominated transport behavior. Our findings open additional avenues for microstructural engineering of materials for thermoelectric and thermal management applications, enabling simultaneous control over mechanical, electronic, and thermal properties.
Materials Science (cond-mat.mtrl-sci)
Entropy Stabilized ZrHfCoNiSnSb Half-Heusler Alloy for Thermoelectric Applications: A Theoretical Prediction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Half-Heusler (HH) alloys are potential thermoelectric materials for use at elevated temperatures due to their high Seebeck coefficient and superior mechanical and thermal stability. However, their enhanced lattice thermal conductivity is detrimental to thermoelectric applications. One way to circumvent this problem is to introduce mass disorder at lattice sites by mixing the components of two or more alloys. Such systems are typically stabilized by the entropy of mixing. In this work, using computational tools, we propose a mixed HH, namely, ZrHfCoNiSnSb, which can be formed by the elemental compositions of the parent half-Heuslers ZrNiSn/HfNiSn and HfCoSb/ZrCoSb. We propose that this new compound can be synthesized at elevated temperatures, as its Gibbs free energy is reduced due to higher configurational entropy, making it more thermodynamically stable than the parent compounds under such conditions. Our calculations indicate that it is a dynamically stable semiconductor with a band gap of 0.61 eV. Its lattice thermal conductivity at room temperature is $ 5.39~\text{Wm}^{-1}\text{K}^{-1}$ , which is significantly lower than those of the parent compounds. The peak value of this alloy’s figure of merit (ZT) is 1.00 for the n-type carriers at 1100 K, which is 27% more than the best figure of merit obtained for the parent compounds.
Materials Science (cond-mat.mtrl-sci)
Emergent Kitaev materials in synthetic Fermi-Hubbard bilayers
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-23 20:00 EDT
Daniel González-Cuadra, Alejandro Bermudez
We investigate the emergence of bond-directional spin-spin interactions in a synthetic Fermi-Hubbard bilayer that can be realized with ultracold fermions in Raman optical lattices. The model exploits synthetic dimensions to couple two honeycomb layers, each corresponding to a different hyperfine atomic state, via Raman-assisted tunneling and, moreover, via an inter-layer Hubbard repulsion due to the cold-atom scattering. In the strong-coupling regime at half filling, we derive effective spin Hamiltonians for the kinetic exchange featuring Kitaev, Heisenberg, off-diagonal exchange ($ \Gamma$ -couplings), as well as tunable Dzyaloshinskii-Moriya interactions. We identify specific configurations that generate both ferromagnetic and antiferromagnetic Kitaev couplings with various perturbations of relevance to Kitaev materials, providing a tunable platform that can explore how quantum spin liquids emerge from itinerant fermion systems. We analyze the Fermi-liquid and Mott-insulating phases, highlighting a correspondence between Dirac and Majorana quasi-particles, with possible phase transitions thereof. In an extreme anisotropic limit, we show that the model reduces to an inter-layer ribbon in a quasi-1D ladder, allowing for a numerical study of the correlated ground state using matrix product states. We find a transition from a symmetry-protected topological insulator to a Kitaev-like regime characterized by nonlocal string order. Our results establish that cold-atom quantum simulators based on Raman optical lattices can be a playground for extended Kitaev models, bridging itinerant fermionic systems and spin-liquid physics.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
From Spin Waves to Monte Carlo Simulations: Compiling an Experimental Exchange Interaction Dataset for Magnetic Materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Mojtaba Alaei, Zahra Mosleh, Nafise Rezaei, Artem R. Oganov
Inelastic neutron scattering data on magnetic crystals are highly valuable in materials science, as they provide direct insight into microscopic magnetic interactions. Using spin wave theory, these interactions can be extracted from magnetic excitations observed in such experiments. However, these datasets are often scattered across the literature and lack standardization, limiting their accessibility and usability. In this paper, we compile and standardize Heisenberg exchange interaction data for magnetic materials obtained from inelastic neutron scattering experiments. Through an extensive literature review, we identify experimental data for approximately 100 magnetic materials. The standardized dataset includes mapping the results of various Heisenberg Hamiltonians into a unified standard form, visualizations of crystal structures with annotated exchange interactions, and input and output files from Monte Carlo simulations performed for each compound using the ESpinS code. Using experimentally determined exchange interactions, we calculate transition temperatures $ T_c$ via classical Monte Carlo simulations. Additionally, we assess the effectiveness of the $ S+1)/S$ correction within classical Monte Carlo simulations, finding that it produces transition temperatures in excellent agreement with experimental values in most cases. The complete dataset, along with supporting resources, is publicly available on GitHub.
Materials Science (cond-mat.mtrl-sci)
A primer on Kitaev Model: Basic aspects, material realization, and recent experiments
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-23 20:00 EDT
This elementary review article is aimed to the beginning graduate students interested to know basic aspects of Kitaev model. We begin with a very lucid introduction of Kitaev model and present its exact solution, Hilbert space structure, fractionalisation, spin-spin correlation function and topological degeneracy in an elementary way. We then discuss the recent proposal of realizing Kitaev interaction in certain materials. Finally we present some recent experiments done on these materials, mainly magnetization, susceptibility, specific heat and thermal Hall effect to elucidate the recent status of material realization of coveted Kitaev spin-liquid phase. We end with a brief discussion on other theoretical works on Kitaev model from different many-body aspects.
Strongly Correlated Electrons (cond-mat.str-el)
41 page, 35 figures. arXiv admin note: text overlap with arXiv:2006.11549
2025 J. Phys.: Condens. Matter 37 193002
Thermoelectric performance of quantum dots embedded in an Aharonov-Bohm ring: a Pauli master equation approach
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-23 20:00 EDT
Parbati Senapati, Prakash Parida
Within linear response theory using Pauli master equation approach, we have investigated the thermoelectric properties of quantum dots (QDs) embedded in an Aharonov-Bohm (AB) ring weakly coupled to two metallic electrodes. This study explores the impact of magnetic flux on thermoelectric transport, emphasizing the role of quantum interference induced by the flux. When the magnetic flux is varied from 0 to one quantum of flux $ \Phi = \Phi_{0} = \frac{h}{e}$ , both the electrical conductance and the thermoelectric figure of merit ($ ZT$ ) significantly increase by two order of magnitude. Moreover, our investigation into the effects of onsite and inter-site Coulomb interactions in this nanojunction indicates that an optimal $ ZT$ is attained with moderate onsite Coulomb interaction and minimal inter-site Coulomb interaction. We briefly discussed the effects of asymmetric arrangements of triple QDs within an AB ring. However, within our parameter regime, a symmetric arrangement offers superior thermoelectric performance compared to asymmetric configurations. Furthermore, we explored how increasing the number of QDs in the ring enhances the thermoelectric properties, resulting in a potential $ ZT$ value of around $ 0.43$ . This study shows that arranging multiple QDs symmetrically in an AB ring can result in significant thermoelectric performance in nanostructured system at low temperatures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Attractive and repulsive angulons in superfluid environments
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-23 20:00 EDT
Wei Zhang, Zhongda Zeng, Tao Shi
We investigate the in- and out-of-equilibrium phenomena of a rotational impurity – specifically, a linear molecule – coupled to a nonconventional environment, a helium nanodroplet. By employing a Lee-Low-Pines-like transformation combined with a multireference configuration approach, we self-consistently account for the molecule’s backaction on the superfluid bath and accurately capture the complex entanglement between the molecule’s rotational degrees of freedom and the bath excitations. Our findings reveal that, in the ground state, the impurity induces a density defect in the superfluid bath, giving rise to two novel types of excited states: (a) attractive angulon states, analogous to bound states in photonic crystals and Yu-Shiba-Rusinov bound states in superconductors, localized within the density defect region; and (b) long-lived repulsive angulon states in dilute environments. Rotational spectroscopy demonstrates a crossover from repulsive to attractive angulon states as the bath density increases. This work paves the way for exploring novel nonequilibrium phenomena of quantum impurities in interacting environments.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph), Chemical Physics (physics.chem-ph), Quantum Physics (quant-ph)
7 pages, 4 figures
Phys. Rev. A 111, 043317 (2025)
DFT exploration of pressure dependent physical properties of the recently discovered La3Ni2O7 superconductor
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-23 20:00 EDT
Md. Enamul Haque, Ruman Ali, M. A. Masum, Jahid Hassan, S. H. Naqib
The recent discovery of superconductivity in Ruddlesden-Popper bilayer nickelate La3Ni2O7 under pressure has drawn a lot of interest. La3Ni2O7 is isostructural with cuprates in some respect. Investigation of its properties will undoubtedly provide new insights into high-Tc superconductivity. In the present work, we study structural, mechanical, elastic, optoelectronic, thermophysical properties, and Fermi surface topology of La3Ni2O7 under pressure within the range of 30-40 GPa employing the density functional theory (DFT). The calculated structural parameters agree well with the earlier experimental findings. The structural, mechanical, and thermodynamical stability is justified across the entire pressure range. The computed elastic moduli classify the compound as ductile, and the material’s ductility is largely unaffected by pressure. The compound has a high level of machinability index and dry lubricity. The electronic band structure reveals metallic feature of La3Ni2O7. The Debye temperature, thermal conductivity, and melting temperature increase with increasing pressure, but in an anomalous manner. The characteristic peaks in refractive index, reflectivity, and photoconductivity exhibit a small shift towards higher energy for all polarizations of the electric field vector with increasing pressure. The investigated material might be a good ultraviolet radiation absorber and can be used as an anti-reflection system. Moreover, the pressure dependent electronic density of states at the Fermi level, pressure induced negligible variations in the repulsive Coulomb pseudopotential, and the changes in the Debye temperature have been used to explore the effect of pressure on the superconducting transition temperature in this study.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
Instability of oxide perovskite surfaces induced by vacancy formation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Ned Thaddeus Taylor, Michael Thomas Morgan, Steven Paul Hepplestone
This work presents a first principles study of the (001) surface energetics of nine oxide perovskites, with a focus on the role of surface vacancies in determining termination stability. Additionally, investigation into the behaviour of vacancies as a function of depth from the surface in these perovskites, ABO$ _{3}$ (A=Ca, Sr, Ba; B=Ti, Zr, Sn), is carried out, and results are compared to formation of the vacancies in bulk. Combining results from these investigations reveals a general trend for all nine perovskites - the undefected AO surface is more energetically favourable to form than the BO2 surface. This dominance of the AO over the BO2 surface is further enforced by the phase diagrams of perovskite surfaces. However, A-site vacancies at the AO surface are far more favourable (1-2 eV lower in energy) than B-site vacancies at the BO2 surface. Charged vacancies only drive this further under oxygen-rich conditions, showing a smaller range of stability for the AO than the BO2 surface. These results indicates that, whilst the AO surface is easier to form, the BO2 surface will display better long term stability, making it more suitable for use in potential applications. This study furthers the understanding of oxide perovskite (001)-terminated surface stability, which will aid in surface growth and manufacturing.
Materials Science (cond-mat.mtrl-sci)
34 pages in main article (40 pages in the supplementary material), 6 figures in the main article (12 figures in the supplementary material)
Universal transparency and fine band structure near the Dirac point in HgTe quantum wells
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-23 20:00 EDT
V. Dziom, A. Shuvaev, J. Gospodaric, E. G. Novik, A. A. Dobretsova, N. N. Mikhailov, Z. D. Kvon, Z. Alpichshev, A. Pimenov
Spin-orbit coupling in thin HgTe quantum wells results in a relativistic-like electron band structure, making it a versatile solid state platform to observe and control non-trivial electrodynamic phenomena. Here we report an observation of universal terahertz (THz) transparency determined by fine-structure constant $ \alpha \approx 1/137$ in 6.5 nm-thick HgTe layer, close to the critical thickness separating phases with topologically different electronic band structure. Using THz spectroscopy in magnetic field we obtain direct evidence of asymmetric spin splitting of the Dirac cone. This particle-hole asymmetry facilitates optical control of edge spin currents in the quantum wells.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
6 pages, 2 figures
Phys. Rev. B 106, 045302 (2022)
Defects, Sound Damping, and the Boson Peak in Amorphous Solids
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-23 20:00 EDT
Elijah Flenner, Grzegorz Szamel
Two nearly universal and anomalous properties of glasses, the peak in the specific heat and plateau of the thermal conductivity, occur around the same temperature. This coincidence suggests that the two phenomena are related. Both effects can be rationalized by assuming Rayleigh scaling of sound attenuation and this scaling leads one to consider scattering from defects. Identifying defects in glasses, which are inherently disordered, is a long-standing problem that was approached in several ways. We examine candidates for defects in glasses that represent areas of strong sound damping. We show that some defects are associated with quasi-localized excitations, which may be associated with modes in excess of the Debye theory. We also examine generalized Debye relations, which relate sound damping and the speed of sound to excess modes. We derive a generalized Debye relation that does not resort to an approximation used by previous authors. We find that our relation and the relation given by previous authors are almost identical at small frequencies and also reproduce the independently determined density of states. However, the different generalized Debye relations do not agree around the boson peak. While generalized Debye relations accurately predict the boson peak in two-dimensional glasses, they under estimate the boson peak in three-dimensional glasses.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Soft Condensed Matter (cond-mat.soft)
29 pages, 7 figures
E. Flennear and G. Szamel, J. Phys. Chem. B 2025, 129, 6, 1855-1863
Improving robustness and training efficiency of machine-learned potentials by incorporating short-range empirical potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Zihan Yan, Zheyong Fan, Yizhou Zhu
Machine learning force fields (MLFFs) are powerful tools for materials modeling, but their performance is often limited by training dataset quality, particularly the lack of rare event configurations. This limitation undermines their accuracy and robustness in long-time and large-scale molecular dynamics simulations. In this work, we present a hybrid MLFF framework that integrates an empirical short-range repulsive potential and demonstrates improved robustness and training efficiency. Using solid electrolyte Li$ _7$ La$ _3$ Zr$ _2$ O$ _{12}$ (LLZO) as a model system, we show that purely data-driven MLFFs fail to prevent unphysical atomistic clustering in extended simulations due to inadequate short-range repulsion. In contrast, the hybrid force field eliminates these artifacts, enabling stable long-time simulations, which are critical for studying various properties of LLZO. The hybrid framework also reduces the need for extensive active learning and performs well with just 25 training configurations. By combining physics-driven constraints with data-driven flexibility, this approach is compatible with most existing MLFF architectures and establishes a universal paradigm for developing robust, training-efficient force fields for complex material systems.
Materials Science (cond-mat.mtrl-sci)
9 pages, 5 figures
ErMn$_6$Sn$_6$: A Promising Kagome Antiferromagnetic Candidate for Room-Temperature Nernst Effect-based thermoelectrics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Olajumoke Oluwatobiloba Emmanuel, Shuvankar Gupta, Xianglin Ke
The Nernst effect, the generation of a transverse electric voltage in the presence of longitudinal thermal gradient, has garnered significant attention in the realm of magnetic topological materials due to its superior potential for thermoelectric applications. In this work, we investigate electronic and thermoelectric transport properties of a Kagome magnet ErMn$ _6$ Sn$ _6$ , a compound showing an incommensurate antiferromagnetic phase followed by a ferrimagnetic phase transition upon cooling. We show that in the antiferromagnetic phase ErMn$ _6$ Sn$ _6$ exhibits both topological Nernst effect and anomalous Nernst effect, analogous to the electric Hall effects, with the Nernst coefficient reaching 1.71 uV/K at 300 K and 3 T. This value surpasses that of most of previously reported state-of-the-art canted antiferromagnetic materials and is comparable to recently reported other members of RMn$ _6$ Sn$ _6$ (R = rare-earth, Y, Lu, Sc) compounds, which makes ErMn$ _6$ Sn$ _6$ a promising candidate for advancing the development of Nernst effect-based thermoelectric devices.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Published in Advanced Functional Materials
Advanced Functional Materials 2025, 241871
Full Crystallographic Imaging of Hexagonal Boron Nitride Monolayers with Phonon-Enhanced Sum-Frequency Microscopy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Niclas S. Mueller, Alexander P. Fellows, Ben Johna, Andrew E. Naclerio, Christian Carbogno, Katayoun Gharagozloo-Hubmann, Damián Baláž, Ryan A. Kowalski, Hendrik H. Heenen, Christoph Scheurer, Karsten Reuter, Joshua D. Caldwell, Martin Wolf, Piran R. Kidambi, Martin Thämer, Alexander Paarmann
Hexagonal boron nitride (hBN) is an important 2D material for van der Waals heterostructures, single photon emitters, and infrared nanophotonics. The optical characterization of mono- and few-layer samples of hBN however remains a challenge as the material is almost invisible optically. Here we introduce phase-resolved sum-frequency microscopy as a technique for imaging monolayers of hBN grown by chemical vapor deposition (CVD) and visualize their crystal orientation. A combination of femtosecond mid-infrared (IR) and visible laser pulses is used for sum-frequency generation (SFG), which is imaged in a wide-field optical microscope. The IR laser resonantly excites a phonon of hBN that leads to an ~800-fold enhancement of the SFG intensity, making it possible to image large 100x100 {\mu}m2 sample areas in less than 1 s. Implementing heterodyne detection in combination with azimuthal rotation of the sample further provides full crystallographic information. Through combined knowledge of topography and crystal orientation, we find that triangular domains of CVD-grown monolayer hBN have nitrogen-terminated zigzag edges. Overall, SFG microscopy can be used as an ultra-sensitive tool to image crystal structure, strain, stacking sequences, and twist angles, and is applicable to the wide range of van der Waals structures, where location and identification of monolayer regions and interfaces with broken inversion symmetry is of paramount importance.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
Ge${1-x}$Si${x}$ single crystals for Ge hole spin qubit integration
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Andreas Fuhrberg, Pia M. Düring, Olena Fedchenko, Olena Tkach, Yaryna Lytvynenko, Kevin Gradwohl, Sergii Chernov, Andrei Gloskovskii, Christoph Schlueter, Gerd Schönhense, Hans-Joachim Elmers, Martina Müller
Spin qubits are fundamental building blocks of modern quantum computing devices. The path of Ge-based hole-spin qubits has several advantages over Si-based electron-spin systems, such as the absence of valley band degeneracy, the possibility of efficient field control due to large spin-orbit coupling, and smaller effective masses. Among the possible Ge qubit devices, Ge/GeSi planar heterostructures have proven to be favourable for upscaling and fabrication. The Si concentration of the straining GeSi buffer serves as an important tuning parameter for the electronic structure of Ge/GeSi qubits. A particularly low Si concentration of x = 0.15 of the Ge$ _{0.85}$ Si$ _{0.15}$ crystal should enable minimal lattice strain for spin qubit heterostructures, which is difficult to stabilize as a random alloy. We present a synchrotron-based study to investigate the chemical composition, valence band electronic structure and local atomic structure of a Ge$ _{0.85}$ Si$ _{0.15}$ single crystal using the advanced combination of hard X-ray photoelectron spectroscopy (HAXPES), hard X-ray momentum microscopy (HarMoMic) and X-ray photoelectron diffraction (XPD). We found that the Ge$ _{0.85}$ Si$ _{0.15}$ crystal has an individual, uniform valence band structure, with no signs of phase separation. The shapes of the valence bands resemble those of pure Ge, as do the low effective masses. XPD experiments and Bloch wave calculations, show the Si atoms located at Ge lattice sites within the crystal, forming a random alloy. This high chemical, electronic and structural quality of Ge$ _{0.85}$ Si$ _{0.15}$ single-crystal substrates is of crucial importance for their implementation to enable long spin lifetimes in Ge-based hole-spin qubits. The results emphasise the power of combined X-ray spectromicroscopy techniques, which provide key insights into the qubit building blocks that form the basis of quantum technologies.
Materials Science (cond-mat.mtrl-sci)
Criticality and magnetic phases of Ising Shastry-Sutherland candidate holmium tetraboride
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-23 20:00 EDT
Guga Khundzakishvili, Bishnu P. Belbase, Pravin Mahendran, Kevin Zhang, Hanjing Xu, Eliana Stoyanoff, Joseph G. Checkelsky, Yaohua Liu, Linda Ye, Arnab Banerjee
Frustrated magnetic systems arising in geometrically constrained lattices represent rich platforms for exploring unconventional phases of matter, including fractional magnetization plateaus, incommensurate orders, and complex domain dynamics. However, determining the microscopic spin configurations that stabilize such phases is a key challenge, especially when in-plane and out-of-plane spin components coexist and compete. Here, we combine neutron scattering and magnetic susceptibility experiments with simulations to investigate the emergence of field-induced fractional plateaus and the related criticality in a frustrated magnet holmium tetraboride (HoB4) that represents the family of rare earth tetraborides that crystalize in a Shastry-Sutherland lattice in the ab plane. We focus on the interplay between classical and quantum criticality near phase boundaries as well as the role of material defects in the stabilization of the ordered phases. We find that simulations using classical annealing can explain certain observed features in the experimental Laue diffraction and the origin of multiple magnetization plateaus. Our results show that defects and out of plane interactions play an important role and can guide the route towards resolving microscopic spin textures in highly frustrated magnets.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Thermal rectification and phonon properties in partially perforated graphene
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
Markos Poulos, Konstantinos Termentzidis
In this work, a thermal rectification ratio $ \eta$ of 18.5% was observed in partially perforated graphene with the use of Molecular Dynamics (MD) simulations. In all cases studied here, heat preferentially flows from the porous to the pristine region and both $ \kappa$ and $ \eta$ increase upon increasing the length of the pristine region and upon decreasing the size of the pores. To interpret the results, the macroscopic “R-Series Model” is applied, attributing rectification to the different temperature dependence of $ \kappa$ of perforated and pristine graphene. According to the model, $ \eta$ is maximized when the two regions composing the structure have matching thermal resistances and mismatching temperature-dependence of $ \kappa$ . The model agrees qualitatively with the MD results, indicating that the latter is the principal rectification mechanism, but it can significantly underestimate $ \eta$ . Phonon analysis further reveals the appearance of new ‘defect’ modes localized around and between pores, resulting in the emergence of a new prominent peak in the phonon Density of States at 520 $ cm^{-1}$ . The study considers key geometric factors such as the length of the pristine region, and the pore size, shape, alignment, and orientation. Pore shape and alignment exert minimal influence on $ \eta$ , although alignment greatly influences $ \kappa$ . Eventually, arranged pores are deemed more efficient than randomly distributed defects for increasing rectification.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
From observed transitions to hidden paths in Markov networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-23 20:00 EDT
Alexander M. Maier, Udo Seifert, Jann van der Meer
The number of observable degrees of freedom is typically limited in experiments. Here, we consider discrete Markov networks in which an observer has access to a few visible transitions and the waiting times between these transitions. Focusing on the underlying structure of a discrete network, we present methods to infer local and global properties of the network from observed data. First, we derive bounds on the microscopic entropy production along the hidden paths between two visible transitions, which complement extant bounds on mean entropy production and affinities of hidden cycles. Second, we demonstrate how the operationally accessible data encodes information about the topology of shortest hidden paths, which can be used to identify potential clusters of states or exclude their existence. Finally, we outline a systematic way to combine the inferred data, resulting in an algorithm that finds the candidates for a minimal graph of the underlying network, i.e., a graph that is part of the original one and compatible with the observations. Our results highlight the interplay between thermodynamic methods, waiting-time distributions and topological aspects like network structure, which can be expected to provide novel insights in other set-ups of coarse graining as well.
Statistical Mechanics (cond-mat.stat-mech)
Locally Machine-Learnability of Density of Electronic States
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-23 20:00 EDT
The electronic density of states (DOS) plays a crucial role in determining the properties of materials. In this study, we investigate the machine learnability of additive atomic contributions to the electronic DOS. Our approach focuses on atom-projected DOS rather than structural DOS. This method for structure-property mapping is both scalable and transferable, achieving high prediction accuracy for pure and compound silicon and carbon structures of varying sizes and configurations. Furthermore, we demonstrate the effectiveness of our method on the complex Sn-S-Se compound structures. By employing locally trained DOS, we significantly enhance the accuracy in predicting secondary material properties, such as band energy, Fermi level, heat capacity, and magnetic susceptibility. Our findings indicate that directly learning atomic DOS, rather than structural DOS, improves the efficiency, accuracy, and interpretability of machine learning in structure-property mapping. This streamlined approach reduces computational complexity, paving the way for the examination of electronic structures in materials without the need for computationally expensive ab initio calculations.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)