CMP Journal 2026-06-17
Statistics
Nature: 25
Nature Materials: 1
Nature Physics: 2
arXiv: 81
Nature
Towards Conversational AI for Disease Management
Original Paper | Diseases | 2026-06-16 20:00 EDT
Valentin Liévin, Anil Palepu, Wei-Hung Weng, Khaled Saab, David Stutz, Yong Cheng, Kavita Kulkarni, S. Sara Mahdavi, Joëlle Barral, Dale R. Webster, Katherine Chou, Avinatan Hassidim, Yossi Matias, James Manyika, Ryutaro Tanno, Vivek Natarajan, Adam Rodman, Tao Tu, Alan Karthikesalingam, Mike Schaekermann
While large language models (LLMs) have shown promise in diagnostic dialogue1, their capabilities for effective management reasoning–including disease progression, therapeutic response, and safe medication prescription–remain under-explored. We advance the previously demonstrated diagnostic capabilities of the Articulate Medical Intelligence Explorer (AMIE)1-3 through a new LLM-based agentic system optimized for multi-visit clinical management and dialogue. To ground its reasoning in authoritative clinical knowledge, AMIE leverages Gemini’s long-context capabilities4, combining in-context retrieval with structured reasoning to align its output with up-to-date clinical practice guidelines and drug formularies. In a randomized, blinded virtual Objective Structured Clinical Examination (OSCE) study, AMIE was compared to 21 primary care physicians (PCPs) across 100 multi-visit case scenarios designed to reflect UK NICE Guidance and BMJ Best Practice guidelines. AMIE was non-inferior to PCPs in management reasoning as assessed by specialists and scored better in both preciseness of treatments and investigations, and in its alignment with and grounding in clinical guidelines. To benchmark medication reasoning, we developed RxQA, a multiple-choice question benchmark derived from two national drug formularies (US, UK) and validated by board-certified pharmacists. Though AMIE and PCPs both benefited from the ability to access external drug information, AMIE outperformed PCPs on higher difficulty questions. While further research would be needed before real-world translation, AMIE’s strong performance across evaluations marks a significant step towards conversational AI as a tool in disease management.
Diseases, Health care
Emergent decadal predictability in Antarctic contribution to sea-level rise
Review Paper | Cryospheric science | 2026-06-16 20:00 EDT
Felicity S. McCormack, Mathieu Morlighem, Frank Pattyn, Alexander A. Robel, Hélène Seroussi
Despite large uncertainties associated with future mass loss from the Antarctic Ice Sheet, ice-sheet models show that the rate of sea-level rise from Antarctic ice loss in 2025 is strongly predictive of the rate for the next several decades, regardless of emission pathway or model complexity. This finding is robust across all models that were considered in the Intergovernmental Panel on Climate Change Sixth Assessment Report global mean sea-level projections, including the low-likelihood, high-impact scenarios of sea-level rise. Given this strong near-term decadal predictability, ice-sheet models that can accurately reproduce present-day ice-mass loss provide a reliable basis for near-term sea-level planning and adaptation through to mid-century. The predictability breaks down by the end of the twenty-first century as feedbacks, such as those related to marine ice-sheet retreat, begin to emerge, leading to accelerating ice loss. Drawing on these results, we identify key feedback mechanisms that can account for the transition between near-term decadal predictability and the longer-term, feedback-driven evolution, and suggest priorities for ice-sheet model development aimed at resolving long-term sea-level rise uncertainty.
Cryospheric science, Environmental impact
A distant brown dwarf coplanar to a warm Jupiter and a hot super-Earth
Original Paper | Exoplanets | 2026-06-16 20:00 EDT
Matías I. Jones, Luca Naponiello, Trifon Trifonov, Rafael Brahm, Gabriele Pichierri, Lorena Acuña-Aguirre, Robert J. De Rosa, Marcelo Tala Pinto, Aldo S. Bonomo, Luigi Mancini, Alessandro Sozzetti, Yared Reinarz, Alessandro Morbidelli, Néstor Espinoza, Giovanni Rosotti, Eric L. Nielsen, Stefan Y. Stefanov, Thomas Henning, Andrés Jordán, Jan Eberhardt, Artie Hatzes, Leonardo Vanzi, Jan Janik, Petr Kabath
In transiting planetary systems, in which planetary sizes are accurately determined from transit observations, the presence of transit-timing variations1 (TTVs), especially when combined with radial velocity (RV) data, provides powerful constraints on masses and orbital eccentricities. Together, these measurements offer crucial insights into system architecture, formation mechanisms and dynamical evolution. We present long-term RV and transit/TTV monitoring of the relatively young star (age approximately 1 Gyr) TOI-201, revealing an exceptional multi-planet system composed of a hot super-Earth (SE) size planet transiting every 5.8 days, a warm Jupiter (WJ) on a 53-day orbit and an eccentric (e = 0.62) low-mass brown dwarf (BD) on an approximately 8-year orbit, with an estimated mass MBD of about 16 Jupiter masses. The BD is the longest-period transiting substellar object ever characterized by means of RVs and the only one known to be coplanar with inner planets. The architecture of this system suggests that the SE was formed isolated and in the innermost region of the gaseous disk. On the other hand, the orbital configuration of the outer companions suggests a nearly in situ formation of both objects, with the WJ forming in a dense inner disk. Alternatively, the BD might have formed farther out and migrated inward, while increasing its eccentricity owing to interactions with the disk.
Exoplanets, Giant planets, Inner planets
Probing picometre-scale interlayer deformations via hyperbolic polaritons
Original Paper | Nanophotonics and plasmonics | 2026-06-16 20:00 EDT
Shu Zhang, Xiangdong Guo, Xiaowen Zhang, Jiashu Yang, Qinzheng Yu, Zhengyang Mou, Bingze Wu, Chenchen Wu, Shiyu Yang, Yongxin Lan, Peiyi He, Jing Shi, Kaijun Feng, Yuxiang Gao, Qiang Zheng, Shuang Zhang, F. Javier García de Abajo, Zhipei Sun, Mingguang Yao, Feng Ding, Peng Gao, Xiaoxia Yang, Qing Dai
The resilience of van der Waals (vdW) materials to large strain fields makes them an ideal platform for tuning electronic, optical and magnetic properties1,2,3,4. Although in-plane strain is readily mapped, non-invasive and quantitative characterization of out-of-plane strain remains a formidable challenge, particularly for picometre-scale deformations buried at interfaces. Here we demonstrate a polaritonic optical method that uses the mid-infrared out-of-plane hyperbolic polaritons (oHPs) mode to detect interlayer deformations in prototypical vdW polar insulator-hexagonal boron nitride (hBN). This method uses the softening mechanism of out-of-plane transverse optical (oTO) phonons induced by interlayer strain, enabling highly sensitive detection of picometre-scale deformations. Although these oTO phonon modes are typically spectroscopically ‘dark’, their strain response is activated through the oHPs, achieving an atomic displacement sensitivity of about 10 pm (about 8 × 10-7 times the probing wavelength), enabling ultradeep-subwavelength mechanical interlayer deformation detection. This is experimentally validated in both planar hBN and at the buried interface of quantum dot-hBN nanotube heterostructures. This polariton-based picometrology bridges nanomechanics and photonics, providing a non-destructive lens to visualize hidden stress landscapes with atomic precision.
Nanophotonics and plasmonics, Optical sensors
Optical fibre gripper for high-performance 3D micromanipulation
Original Paper | Actuators | 2026-06-16 20:00 EDT
Deng Pan, Kaiwen Liang, Chen Xin, Lei Zhong, Shaojun Jiang, Chenchu Zhang, Liang Yang, Zhiqiang Wang, Zhaoxin Lao, Jincheng Ni, Chaowei Wang, Jiawen Li, Shenglai Zhen, Benli Yu, Zhixiang Huang, Fang-Wen Sun, Jiaru Chu, Yanlei Hu, Li Zhang, Dong Wu
Optical tweezers offer precise, non-contact control, but operate in a limited force regime and impose strict requirements on the characteristics of the targets as well as the environmental conditions1,2,3,4. Millimetre-scale mechanical tweezers can offer higher gripping force but are not suitable for precise manipulations5,6,7,8,9,10,11. Integrating microgrippers directly at the optical fibres provides a new approach for precise micromanipulation. However, existing fibre-integrated tweezers still face challenges in achieving high-performance manipulation of micro-objects (for example, single cells) within narrow spaces, mainly due to simplified architectures, constrained designs and millimetre-scale footprints12,13,14. Here we report a three-dimensional (3D) optical fibre gripper (OFG), which is fabricated by two-step, two-photon polymerization. The OFG consists of rigid photoresist microclaws and soft thermoresponsive hydrogel muscle doped with silver nanoparticles, and its size is only 38 × 38 × 61 μm3. The OFG exhibits a force-to-mass ratio of about 340 μN mg-1, outperforming previously reported fibre-integrated tweezers by one to two orders of magnitude. The OFG can manipulate opaque particles, irregular micromechanical components and diverse single-cell types. We further demonstrated its potential in 3D microassembly of complex microdevices (bearings, shafts and gearboxes) and biomimetic sampling in the narrow environment (<300 μm). These results position the OFG as a compact fibre-tip manipulator for 3D micromanipulation, offering reversible and tunable gripping in an intermediate force regime between optical field trapping and millimetre-scale mechanical tweezers.
Actuators, Laser material processing, Mechanical engineering, Microbiology techniques, Polymers
A prototype differential atom interferometer for fundamental physics
Original Paper | Cosmology | 2026-06-16 20:00 EDT
C. F. A. Baynham, R. Hobson, O. Buchmüller, D. Evans, L. Hawkins, L. Iannizzotto Venezze, A. Josset, D. Lee, E. Pasatembou, B. E. Sauer, M. R. Tarbutt, T. Walker, O. Ennis, U. Chauhan, A. Brzakalik, S. Dey, S. Hedges, B. Stray, M. Langlois, K. Bongs, T. Hird, S. Lellouch, M. Holynski, B. Bostwick, J. Chen, Z. Eyler, V. Gibson, T. L. Harte, C. C. Hsu, M. Karzazi, C. Lu, B. Millward, J. Mitchell, N. Mouelle, B. Panchumarthi, J. Scheper, U. Schneider, X. Su, Y. Tang, K. Tkalčec, M. Zeuner, S. Zhang, Y. Zhi, L. Badurina, A. Beniwal, D. Blas, J. Carlton, J. Ellis, C. McCabe, G. Parish, D. Pathak Govardhan, V. Vaskonen, T. Bowcock, K. Bridges, A. Carroll, J. Coleman, G. Elertas, S. Hindley, C. Metelko, H. Throssell, J. N. Tinsley, E. Bentine, M. Booth, D. Bortoletto, N. Callaghan, C. Foot, C. Gómez-Monedero, K. Hughes, A. James, T. Leese, A. Lowe, J. March-Russell, J. Sander, J. Schelfhout, I. Shipsey, D. Weatherill, D. Wood, S. N. Balashov, M. G. Bason, K. Hussain, H. Labiad, P. Majewski, A. L. Marchant, D. Newbold, Z. Pan, Z. Tam, T. C. Thornton, T. Valenzuela, M. G. D. van der Grinten, I. Wilmut, K. Clarke, A. Vick, S. Hedges, B. Stray, M. Langlois, K. Bongs, B. Bostwick, B. Panchumarthi, X. Su, M. Zeuner, Y. Zhi, L. Badurina, A. Beniwal, D. Blas, V. Vaskonen, M. G. D. van der Grinten
Gravitational waves and ultralight dark matter are among the most compelling frontiers in fundamental physics, motivating proposals for very-long-baseline atom interferometerssuch as AION1, MAGIS2, AICE3 and AEDGE4 that aim to detect at frequencies at which ground-based5 and space-borne6 laser interferometers lose sensitivity. Very-long-baseline atom interferometers look for signals by comparing the quantum phase evolution of widely separated atomic ensembles interrogated by a common laser. However, their performance depends critically on suppressing noise sources, particularly laser phase noise. The experimental validation of such noise rejection remains an important challenge. Here we demonstrate a prototype differential atom interferometer based on the single-photon clock transition of fermionic 87Sr. Thus, we obtain a gradiometer configuration with a species intrinsically suited to kilometre-scale and space-baseline operation. The instrument operates at the standard quantum limit7 with no excess noise beyond atom shot noise. The differential configuration maintains quantum-limited sensitivity in the presence of several radians of artificially injected laser phase noise per shot, which emulates the conditions expected in a very-long-baseline atom interferometer. We also demonstrate the recovery of coherent oscillatory signals across a broad frequency range under fully phase-randomized conditions, a capability that is inaccessible to a single interferometer operating in the same regime. These results provide an experimental validation of the noise-immune measurement principle underlying very-long-baseline atom interferometers and mark an important step towards next-generation quantum sensors for gravitational-wave detection and searches for ultralight dark matter8,9.
Cosmology, Laboratory astrophysics, Matter waves and particle beams, Ultracold gases
Structure of the pre-initiation complex explains CMGE biogenesis
Original Paper | Cryoelectron microscopy | 2026-06-16 20:00 EDT
Thomas Pühringer, Berta Canal, Giacomo Palm, Agata Butryn, Emma C. Couves, Oliver Willhoft, Jacob S. Lewis, John F. X. Diffley, Alessandro Costa
When cells enter S phase, bidirectional DNA replication is initiated through the kinase-regulated recruitment of three activators (Cdc45, GINS and Pol ε) to a duplex-DNA-loaded double hexamer of minichromosome maintenance (MCM) ATPases. Together, these proteins form two CMGE helicases that establish divergent replication forks as they become separated1. Here, to gain an understanding of CMGE biogenesis, we reconstituted the pre-initiation complex with purified yeast proteins. The cryo-electron-microscopy structure shows a set of firing factors caught in the act of assembling two symmetrical CMGEs. We show how stepwise complex formation reshapes MCM in preparation for DNA opening, and we explain how ATP promotes firing-factor ejection and CMGE maturation. We find that although Sld2 facilitates the recruitment of GINS to MCM, as expected, it also aids the efficient separation of the CMGE dimer, and is essential for the ejection of the lagging strand from MCM. These findings have direct implications for our understanding of the metazoan Sld2 orthologue, RECQL4, and point to a replication-fork establishment mechanism that is conserved across eukaryotes.
Cryoelectron microscopy, Origin firing
A 98-qubit trapped-ion quantum computer with all-to-all connectivity
Original Paper | Atomic and molecular physics | 2026-06-16 20:00 EDT
Anthony Ransford, M. S. Allman, Jake Arkinstall, J. P. Campora III, Samuel F. Cooper, Robert D. Delaney, Joan M. Dreiling, Brian Estey, Caroline Figgatt, Alex Hall, Ali A. Husain, Akhil Isanaka, Colin J. Kennedy, Nikhil Kotibhaskar, Ivaylo S. Madjarov, Karl Mayer, Alistair R. Milne, Annie J. Park, Adam P. Reed, Riley Ancona, Molly P. Andersen, Pablo Andres-Martinez, Will Angenent, Liz Argueta, Benjamin Arkin, Leonardo Ascarrunz, William Baker, Corey Barnes, John Bartolotta, Jordan Berg, Ryan Besand, Bryce Bjork, Matt Blain, Paul Blanchard, Robin Blume-Kohout, Matt Bohn, Agustíin Borgna, Daniel Y. Botamanenko, Robert Boutelle, Natalie Brown, Grant T. Buckingham, Nathaniel Q. Burdick, William Cody Burton, Varis Carey, Christopher J. Carron, Joe Chambers, Jia Wen Chan, John Children, Victor E. Colussi, Steven Crepinsek, Andrew Cureton, Joe Davies, Daniel Davis, Matthew DeCross, David Deen, Conor Delaney, Davide DelVento, B. J. DeSalvo, Jason Dominy, Sydney Drotar, Ross Duncan, Vanya Eccles, Alec Edgington, Neal Erickson, Stephen Erickson, Christopher T. Ertsgaard, Jay Esposito, Bruce Evans, Tyler Evans, Maya I. Fabrikant, Andrew Fischer, Cameron Foltz, Michael Foss-Feig, David Francois, Brad Freyberg, Charles Gao, Robert Garay, Jane Garvin, David M. Gaudiosi, Christopher N. Gilbreth, Josh Giles, Erin Glynn, Jeff Graves, Azure Hansen, David Hayes, Lukas Heidemann, Bob Higashi, Tyler Hilbun, Jordan Hines, Ariana Hlavaty, Kyle Hoffman, Ian M. Hoffman, Craig Holliman, Isobel Hooper, Bob Horning, James Hostetter, Daniel Hothem, Jack Houlton, Jared Hout, Ross Hutson, Ryan T. Jacobs, Trent Jacobs, Melf Johannsen, Jacob Johansen, Loren Jones, Sydney Julian, Ryan Jung, Aidan Keay, Todd Klein, Mark Koch, Ryo Kondo, Chang Kong, Asa Kosto, Alan Lawrence, David Liefer, Michelle Lollie, Dominic Lucchetti, Nathan K. Lysne, Christian Lytle, Callum MacPherson, Andrew Malm, Spencer Mather, Brian Mathewson, Daniel Maxwell, Lauren McCaffrey, Hannah McDougall, Robin Mendoza, David B. Miller, Michael Mills, Richard Morrison, Louis Narmour, Nhung Nguyen, Lora Nugent, Scott Olson, Daniel Ouellette, Jeremy Parks, Zach Peters, Timothy A. Peterson, Jessie Petricka, Juan M. Pino, Frank Polito, Andrew C. Potter, Matthias Preidl, Gabriel Price, Timothy Proctor, McKinley Pugh, Noah Ratcliff, Daisy Raymondson, Peter Rhodes, Conrad Roman, Craig Roy, Ciaran Ryan-Anderson, Fernando Betanzo Sanchez, George Sangiolo, Tatiana Sawadski, Andrew Schaffer, Peter Schow, Jon Sedlacek, Henry Semenenko, Peter Shevchuk, Susan Shore, Peter Siegfried, Kartik Singhal, Seyon Sivarajah, Thomas Skripka, Lucas Sletten, Ben Spaun, R. Tucker Sprenkle, Paul Stoufer, Mariel Tader, Stephen F. Taylor, Travis H. Thompson, Raanan Tobey, Anh Tran, Tam Tran, Grahame Vittorini, Curtis Volin, Jim Walker, Sam White, Garrett R. Williams, Douglas Wilson, Quinn Wolf, Chester Wringe, Kevin Young, Jian Zheng, Kristen Zuraski, Charles H. Baldwin, Alex Chernoguzov, John P. Gaebler, Steven J. Sanders, Brian Neyenhuis, Russell Stutz, Justin G. Bohnet
Quantum computers require both high-fidelity operations and large qubit numbers to surpass classical capabilities1. Trapped-ion platforms have demonstrated the highest gate fidelities of any modality2,3,4,5,6 but scaling to larger qubit numbers while preserving performance has remained a central challenge. We report on Quantinuum Helios, a 98-qubit trapped-ion quantum processor based on the quantum charge-coupled device (QCCD) architecture7. Helios features 137Ba+ hyperfine qubits8,9, all-to-all connectivity enabled by a rotatable ion storage ring connecting two quantum operation regions by a junction10,11, speed improvements from parallelized operations12 and a new software stack with real-time compilation of dynamic programs13. Averaged over all operational zones in the system, we achieve average infidelities of 2.5(1) × 10-5 for single-qubit (1Q) gates, 7.9(2) × 10-4 for two-qubit (2Q) gates and 3.3(5) × 10-4 for state preparation and measurement (SPAM), none of which are fundamentally limited and probably able to be improved. These component infidelities are predictive of system-level performance in both random Clifford circuits and random circuit sampling (RCS), the latter demonstrating that Helios operates well beyond the reach of classical simulation and establishes a new frontier of fidelity and complexity for quantum computers14.
Atomic and molecular physics, Computer science, Quantum information
Fast formation to reinforce lithium-rich cathodes
Original Paper | Batteries | 2026-06-16 20:00 EDT
Mengjian Fan, Jiantao Li, Guiyang Gao, Benli Jiang, Longlong Fan, Qingxi Yuan, Yinggan Zhang, Hongfei Zheng, Saichao Li, Liang Lin, Zonghai Chen, Yang Ren, Yuanyuan Liu, Wei He, Gaosheng Chen, Baisheng Sa, Laisen Wang, Jie Lin, Dong-Liang Peng, Qingshui Xie
Formation in lithium-ion battery manufacturing typically involves low-rate charge-discharge cycles to establish stable electrode-electrolyte interfaces–a time-consuming process1,2,3,4. Here, our findings on lithium-rich layered oxide cathodes challenge the necessity of conventional formation, which can even shorten battery lifespan. Fast formation, on the other hand, reduces production cost and enhances capacity and stability. Multiscale synchrotron-based techniques show that residual lithium ions after the initial charge are critical for subsequent structural evolution and cycling performance. Deep lithium de-intercalation causes severe structural degradation and capacity loss due to the inherently fragile lithium-deficient matrix. By contrast, the residual lithium ions from fast formation enhance reversibility through a self-pinning effect, preventing pernicious lattice deformation and reinforcing the ion-storage framework. Adjusting the initial charge current density from 0.2 C to 2 C improves reversible capacity by 20% and extends cycle life by more than 36%. This approach can also be extended to other electrode systems, providing insights for more-efficient battery production.
Batteries, Electrochemistry
Revealing competitive interfacial reactions in high-energy Li-S batteries
Original Paper | Batteries | 2026-06-16 20:00 EDT
Shiyuan Zhou, Fei Pei, Qizheng Zheng, Gen Li, Hongyuan Yi, Linzhi Chen, Shi Tang, Qi Kang, Zu-Wei Yin, Sangui Liu, Liangping Xiao, Ling Huang, Yu Qiao, Yunhui Huang, Shi-Gang Sun, Hong-Gang Liao
Charge transfer at solid-liquid interfaces plays a critical role in various energy-storage systems1, particularly under dynamically varying reactant concentrations. Deciphering these intricate reaction pathways remains a substantial challenge, notably in lithium-sulfur (Li-S) batteries, in which achieving high energy density requires efficient conversion of highly concentrated lithium polysulfides (LiPSs)2,3. However, the mechanisms governing lithium sulfide (Li2S) deposition and dissolution under lean electrolyte conditions remain poorly understood. Here, using in situ liquid-cell electron microscopy, we directly visualize concentration-driven phase segregation at the electrode-electrolyte interface. Within these high-concentration interfacial layers (HCILs), competitive surface and solution dictate the charge-transfer dynamics and ultimately govern Li2S deposition at different phase boundaries. Density functional theory (DFT) calculations reveal that the aggregation of LiPSs alters molecular geometry, electronic properties and orbital hybridization, collectively facilitating charge transfer through highly concentrated LiPSs clusters. Guided by these insights, we design optimized electrodes that balance interfacial reaction pathways, enabling fast charging (4 C, 26.8 mA cm-2) and achieving high energy densities exceeding 400 Wh kg-1. These findings provide mechanistic understanding of interfacial reactions under practical working conditions and offer a design strategy to advance Li-S batteries.
Batteries, Imaging techniques
Molecular basis of polyadenylated RNA fate determination in the nucleus
Original Paper | RNA quality control | 2026-06-16 20:00 EDT
Andrii Bugai, Ulrich Hohmann, Ana Lorenzo, Max Graf, Laura Fin, Jérôme O. Rouvière, Laszlo Tirian, Yuhui Dou, Marion Le Rest, Patrik Polák, Dennis Johnsen, Lis Jakobsen, Jens Skorstengaard Andersen, Julius Brennecke, Clemens Plaschka, Torben Heick Jensen
Eukaryotic genomes generate a plethora of polyadenylated (pA+) RNAs1,2, which are packaged into ribonucleoprotein particles (RNPs). To ensure faithful gene expression, functional pA+ RNPs, including protein-coding RNPs, are exported to the cytoplasm, whereas transcripts within non-functional pA+ RNPs are degraded in the nucleus1,2,3,4. How cells distinguish these opposing fates remains unknown. The DExD-box ATPase UAP56 (also known as DDX39B) is a central component of functional pA+ RNPs, and promotes their docking to the nuclear pore complex-anchored TREX-25,6, which triggers transcript release from UAP56 to facilitate export7. Here we reveal that the poly(A) tail exosome targeting (PAXT) connection8 binds a TREX-2-like module, which releases pA+ RNAs from UAP56 for decay by the nuclear exosome. The core of this module consists of a LENG8-PCID2-SEM1 trimer, which we show is structurally and biochemically equivalent to the central GANP-PCID2-SEM1 trimer of TREX-2. Mutagenesis and transcriptomic data demonstrate that the nuclear fate of pA+ RNPs is governed by the contending actions of nucleoplasmic PAXT and nuclear pore complex-associated TREX-2, which interpret RNA-bound UAP56 as a signal for RNA decay or export, respectively. As RNA targets of PAXT are generally short and intron-poor, we propose an overall model for pA+ RNP fate determination whereby the distinct sub-nuclear localizations of PAXT and TREX-2 govern the degradation of short non-functional pA+ RNAs while allowing export of their longer and functional counterparts.
RNA quality control, RNA transport
Rock weathering can counteract river CO2 emissions induced by permafrost thaw
Original Paper | Carbon cycle | 2026-06-16 20:00 EDT
Liwei Zhang, Aaron Bufe, Joshua F. Dean, Gerard Rocher-Ros, Ryan A. Sponseller, Emily H. Stanley, Jan Karlsson, David E. Butman, Ran Liu, Lijun Hou, Jinzhi Ding, Shilong Piao, Xinghui Xia, Tom J. Battin
Climate-induced permafrost thaw unlocks large stores of organic carbon that are mineralized and emitted as carbon dioxide (CO2) from rivers to the atmosphere1. Concurrently, warming and permafrost thaw can increase mineral weathering rates, thus affecting the release and sequestration of inorganic carbon2,3,4. Yet how these biological and geological carbon cycles interact and jointly affect CO2 dynamics (emission compared with drawdown) in permafrost rivers remains unknown5. Here we combine CO2 emissions, organic and inorganic solute concentrations, dual carbon isotopes (δ13C-Δ14C) and geochemical modelling to infer how permafrost thaw may affect river biogeochemistry over decades to centuries across the Qinghai-Tibet Plateau. Leveraging a gradient of thermal permafrost degradation, we find that river CO2 emissions decline, whereas solute fluxes from rock weathering increase with decreasing permafrost cover. Across this region, net CO2 drawdown fluxes from rock weathering are about 35% of river CO2 emissions, varying from around 15% in catchments with continuous permafrost to more than 100% in catchments with discontinuous or isolated permafrost. Thus, carbon fluxes from chemical weathering may become increasingly important with ongoing permafrost thaw, potentially even outpacing river CO2 emissions. Our findings disentangle the interplay between biological and geological carbon fluxes that are important for the cryosphere and the global carbon cycle.
Carbon cycle, Hydrology
Cortical development dynamics across autism spectrum disorder mouse models
Original Paper | Molecular biology | 2026-06-16 20:00 EDT
Lena A. Schwarz, Christoph P. Dotter, Sergey Isaev, Michela Lisi, Daniel Malzl, Christoph Büschl, Sabrina Ladstätter, Bárbara Oliveira, Matteo Barel, Bernadette Basilico, Chaitanya Chintaluri, Sarah Gorkiewicz, Mohammad Goudarzi, Tereza Belinova, Stephan Reichl, Gintarė Sendžikaitė, Satish Arcot Jayaram, Peter Koppensteiner, Christoph Sommer, Tim P. Vogels, Jörg Menche, Igor Adameyko, Peter V. Kharchenko, Christoph Bock, Gaia Novarino
Despite the functional diversity of over 100 causal genes1,2,3, phenotypic convergence across models may reveal common neurobiological processes in autism spectrum disorder (ASD). Here we profiled 251 samples from 11 monogenic mouse models of ASD using single-nucleus multi-omic sequencing across three developmental stages, both sexes and two brain regions. Despite genetic heterogeneity, ASD-linked mutations converged on perturbations of the radial glial cell lineage. These alterations reflect a transient developmental delay rather than lasting lineage misspecification and resolve by postnatal stages. Molecularly, the largest transcriptional differences emerged in neurons at early postnatal stages. These changes included downregulation of synaptic and ion channel-related genes, consistent with homeostatic adaptation or delayed maturation. Network analysis showed molecular convergence across models within each developmental stage, suggesting that diverse mutations linked to ASD impinge on common, stage-specific processes. Convergence becomes less pronounced by postnatal day 14, highlighting the dynamic nature of ASD-associated changes. Cross-genotype heterogeneity is superimposed on stage-specific effects. Electrophysiology corroborated this pattern: mutants generally showed altered neuronal excitability and synaptic properties with model-specific nuances. Our study also highlighted sex-specific gene expression alterations, with female mice often displaying larger effect sizes than male mice. Together, our findings provide a comprehensive view of developmental cellular and molecular dynamics across models of ASD.
Molecular biology, Neuroscience
A blastoporal organizer in a ctenophore
Original Paper | Embryology | 2026-06-16 20:00 EDT
Stanislav Kremnyov, Tatiana Lebedeva, Grigory Genikhovich, Andreas Hejnol
In an iconic experiment in 1924, Hilde Mangold and Hans Spemann established that the dorsal blastopore lip of amphibian embryos functions as an organizer and induces a secondary body axis when transplanted into a host embryo1. This discovery demonstrated that specific embryonic regions can regulate embryonic patterning and lead to the establishment of an entire body axis. Subsequent studies have revealed that cnidarians, the sister group to Bilateria, also possess a blastoporal embryonic organizer2,3. However, the evolutionary origin of the organizer remains unclear. Here we report that the blastopore lip of the ctenophore Mnemiopsis leidyi, a member of the evolutionary sister group to all other metazoans4,5, exhibits organizer activity. We show that transplanted fragments of blastopore lip tissue from M. leidyi gastrula induce secondary pharynx and mouth formation. Moreover, transphyletic transplantation experiments show that the blastopore lip of M. leidyi leads to the generation of a secondary body axis in embryos of the cnidarian Nematostella vectensis. Organizer function in M. leidyi requires both β-catenin and TGFβ signalling, and the TGFβ-family ligands probably provide this inductive capacity. These findings reveal the deep homology of the blastoporal organizer in ctenophores, cnidarians and vertebrates, implying the ancestral organizer role of the blastopore lip. We propose that the emergence of the organizer was an essential innovation that facilitated the change from the temporal cell differentiation of unicellular relatives to the spatial cell differentiation of the first multicellular embryo.
Embryology, Evolutionary developmental biology
Confined migration induces non-lethal DNA damage in developing neurons
Original Paper | Cell migration | 2026-06-16 20:00 EDT
Zhejing Zhang, Andres Canela, Junko Kurisu, Peilin Zou, Takumi Kawaue, Naotaka Nakazawa, Noriko Takeda, Mai Saeki, Masaki Utsunomiya, Merve Bilgic, Fumiyoshi Ishidate, Gianluca Grenci, Takahiro Furuta, Yusuke Kishi, Hiroyuki Sasanuma, Mineko Kengaku
Migratory cells tend to have soft nuclei that deform and penetrate narrow spaces1,2. Extensive nuclear deformation during migration can cause nuclear-envelope rupture and DNA damage in cancer cells, which may contribute to malignant transformation during tumour progression3,4,5,6. However, the importance of DNA damage in physiological migration is less well understood. Here we demonstrate that the migration of neurons in developing cerebral and cerebellar cortices is accompanied by massive DNA double-stranded breaks (DSBs) due to mechanostress during passage through narrow interstitial spaces. In contrast to many other migratory cells, these DSBs occur without detectable nuclear envelope rupture. Confined migration increases topoisomerase-IIβ covalently bound DSBs, and these lesions are repaired through non-homologous end-joining during brain development without causing cell death. Genome sequencing revealed that DSBs tend to occur at transcriptionally inactive regions. The deletion of ligase IV at the onset of neuronal migration leads to persistent DSB accumulation in cerebellar neurons with moderate transcriptional changes in genes related to synaptic function, neuronal development and stress and immune responses. The mutant mouse develops mild motor deficits in later life, suggesting that the DNA damage generated during normal brain development poses a potential disease risk if left unrepaired.
Cell migration, Double-strand DNA breaks, Neuronal development
Analysis of 173,303 exomes and genomes in the Pakistan Genome Resource
Original Paper | Cardiovascular diseases | 2026-06-16 20:00 EDT
Christopher Koch, Shareef Khalid, Maleeha Zaman Khan, Shruthi Bandyadka, Brian Doyon, Daniel P. Denning, Muhammad Jahanzaib, Muhammad Rehan Mian, Wafa Gul, Muhammad Bilal Liaqat, Aneeqa Bano, Marium Dahar, Namra Saqib, Lubna Kamani, Nazish Butt, Anjum Jalal, Riffat Sultana, Shahid Abbas, Musfireh Siddiqeh, Muhammad Haroon, Asadullah Khan, Khalid Parvez Babar, Aflak Rasheed, Javed Iqbal, Faizan Aslam, Umar Usman, Muhammad Akram Bajwa, Ali Hyder, Muhammad Sadik Memon, Nauman Hashmani, Mohsin Iqbal Haroon, Ambreen Muddassir, Syed Asif Raza Zaidi, Mateen Akram, Muhammad Hussain, Saima Naz Mohsin, Samreen Bugti, Tariq Mehmood, Abdul Lateef Rodeni, Shahid Mukhtar, Tahir Rasool, Adil Mahmood, Muhammad Noor Wazir, Sheraz Jamal Khan, Muhammad Asghar Khan, Rahmat Ghaffar, Sanaullah Jan, Noor Ul Hadi, Roshina Anjum, Rehan Abdullah, Muhammad Usman Musharraf, Muhammad Tahir Bashir, Muhammad Ali, Irfan Majeed, Muhammad Haroon Bilal, Shahzad Ali Khan, Chihiro Hata, Ikuyo Kou, Makoto Asaumi, Wataru Morii, Katherine R. Smith, Kousik Kundu, Kieren Lythgow, Stewart MacArthur, Sebastian Wasilewski, Slavé Petrovski, Aris Baras, Gonçalo Abecasis, Adolfo Ferrando, Giovanni Coppola, Andrew Deubler, Luca A. Lotta, John D. Overton, Jeffrey G. Reid, Alan Shuldiner, Katherine Siminovitch, Jason Portnoy, Marcus B. Jones, Lyndon Mitnaul, Alison Fenney, Jonathan Marchini, Manuel Allen Revez Ferreira, Maya Ghoussaini, Mona Nafde, William Salerno, Cristen Willer, Lourdes Crane, Christina Beechert, Erin Fuller, Laura M. Cremona, Eugene Kalyuskin, Hang Du, Caitlin Forsythe, Zhenhua Gu, Kristy Guevara, Michael Lattari, Alexander Lopez, Kia Manoochehri, Prathyusha Challa, Manasi Pradhan, Raymond Reynoso, Ricardo Schiavo, Maria Sotiropoulos Padilla, Chenggu Wang, Sarah E. Wolf, Manan Goyal, George Mitra, Sanjay Sreeram, Rouel Lanche, Vrushali Mahajan, Sai Lakshmi Vasireddy, Gisu Eom, Krishna Pawan Punuru, Sujit Gokhale, Benjamin Sultan, Pooja Mule, Mudasar Sarwar, Muhammad Aqeel, Xiaodong Bai, Lance Zhang, Sean O’Keeffe, Razvan Panea, Evan Edelstein, Ayesha Rasool, Evan K. Maxwell, Boris Boutkov, Alexander Gorovits, Ju Guan, Lukas Habegger, Alicia Hawes, Olga Krasheninina, Samantha Zarate, Adam J. Mansfield, Joshua Backman, Kathy Burch, Adrian Campos, Liron Ganel, Sheila Gaynor, Benjamin Geraghty, Arkopravo Ghosh, Salvador Romero Martinez, Christopher Gillies, Lauren Gurski, Eric Jorgenson, Tyler Joseph, Michael Kessler, Jack Kosmicki, Adam Locke, Priyanka Nakka, Karl Landheer, Olivier Delaneau, Anthony Marcketta, Joelle Mbatchou, Arden Moscati, Anita Pandit, Jonathan Ross, Carlo Sidore, Eli Stahl, Timothy Thornton, Sailaja Vedantam, Rujin Wang, Kuan-Han Wu, Bin Ye, Blair Zhang, Andrey Ziyatdinov, Yuxin Zou, Jingning Zhang, Kyoko Watanabe, Mira Tang, Frank Wendt, Suganthi Balasubramanian, Suying Bao, Kathie Sun, Chuanyi Zhang, Sean Yu, Aaron Zhang, David Corrigan, Dhruv Shidhaye, Chen Wang, Keyrun Adhikari, Alexander Lachmann, Brian Hobbs, Jon Silver, William Palmer, Rita Guerreiro, Amit Joshi, Antoine Baldassari, Sarah Graham, Ernst Mayerhofer, Erola Pairo Castineira, Mary Haas, Niek Verweij, George Hindy, Jonas Bovijn, Tanima De, Luanluan Sun, Olukayode Sosina, Arthur Gilly, Peter Dornbos, Juan Rodriguez-Flores, Gannie Tzoneva, Momodou W. Jallow, Anna Alkelai, Ariane Ayer, Veera Rajagopal, Sahar Gelfman, Vijay Kumar, Jacqueline Otto, Jose Bras, Silvia Alvarez, Jessie Brown, Hossein Khiabanian, Joana Revez, Kimberly Skead, Valentina Zavala, Jae Soon Sul, Lei Chen, Sam Choi, Amy Damask, Nan Lin, Charles Paulding, Sameer Malhotra, Joseph Herman, Michelle G. LeBlanc, Nadia Rana, Jennifer Rico-Varela, Jaimee Hernandez, Larizbeth Romero, Ashley Paynter, Randi Schwartz, Jody Hankins, Anna Han, Samuel Hart, Ryan Smith, Ann Perez-Beals, Gina Solari, Johannie Rivera-Picart, Michelle Pagan, Sunilbe Siceron, Juan L. Rodriguez-Flores, Moeen Riaz, Manav Kapoor, Joshua D. Backman, Alan R. Shuldiner, James E. Bradner, Igor Splawski, Asif Rasheed, John E. Dominy, Allan M. Gurtan, Danish Saleheen
Naturally occurring loss-of-function variants in human genes enable drug target discovery because they mimic pharmacological inhibition of proteins. However, the study of these genetic variants is constrained by their rarity. Sequencing of diverse populations, particularly those enriched in familial relatedness, has been postulated to promote discovery of rare genetic variants1,2,3. Here we present the Pakistan Genome Resource, a South Asian biobank with high familial relatedness comprising 173,303 participants, who collectively carry naturally occurring homozygous loss-of-function variants in 6,476 genes. We describe the genetic architecture of this population, associations between genes and biomarkers, the distribution of loss-of-function variants across molecular pathways, and recall-by-genotype studies of therapeutically relevant genes. The Pakistan Genome Resource expands the catalogue of human genetic variants, provides a comprehensive genetic reference resource for the Pakistani population, and demonstrates the value of studying diverse cohorts to advance human health.
Cardiovascular diseases, Consanguinity, Genome-wide association studies, Rare variants, Target validation
A mosaic of whole-body representations on the human precentral gyrus
Original Paper | Brain-machine interface | 2026-06-16 20:00 EDT
Darrel R. Deo, Elizaveta V. Okorokova, Anna L. Pritchard, Nick V. Hahn, Nicholas S. Card, Samuel R. Nason-Tomaszewski, Justin Jude, Thomas Hosman, Eun Young Choi, Deqiang Qiu, Yuguang Meng, Maitreyee Wairagkar, Claire Nicolas, Foram B. Kamdar, Carrina Iacobacci, Alexander Acosta, Leigh R. Hochberg, Sydney S. Cash, Ziv M. Williams, Daniel B. Rubin, David M. Brandman, Sergey D. Stavisky, Nicholas AuYong, Chethan Pandarinath, John E. Downey, Sliman J. Bensmaia, Jaimie M. Henderson, Francis R. Willett
Understanding how the body is represented in the motor cortex is key to understanding how the brain controls movement. Although the motor cortex has been mapped in animal models at a fine scale1,2,3,4,5,6,7,8,9,10, characterization in humans remains primarily limited to low-resolution recording11,12,13,14,15,16 and stimulation techniques17,18,19,20. Here we created a comprehensive map of the human motor cortex at single-neuron resolution, spanning microelectrode array recordings from 20 arrays across 8 individuals with paralysis from spinal cord injury, amyotrophic lateral sclerosis or brainstem stroke, all enrolled in brain-computer interface clinical trials. These arrays broadly sample the crown of the precentral gyrus (PCG; thought to be composed largely of the premotor cortex (Brodmann area 6)). We found that body parts were highly intermixed, such that the entire body was represented in all sampled locations of the PCG, although the relative strength of body parts was roughly consistent with the motor homunculus17,18. We also found two speech-preferential areas with a broadly tuned, orofacial-dominant area in between them. Throughout the PCG, movement representations of the four limbs were interlinked, with homologous movements of different limbs (for example, toe curl and hand close) having correlated representations. These data provide evidence consistent with an intermixed, interrelated and behaviour-centred organization of the motor cortex3,21. The resulting map also provides important targeting information for brain-computer interfaces that seek to restore motor function.
Brain-machine interface, Motor cortex
Spatial distribution of the proteome in the human body and in cancers
Original Paper | Proteomics | 2026-06-16 20:00 EDT
Liang Yue, Wenhao Jiang, Sainan Li, Meng Luo, Ning Fan, Xiaolu Zhan, Rui Sun, Honghan Cheng, Zhangzhi Xue, Tong Liu, Qianhe Zhou, Kexin Chen, Tian Lu, Fang Guo, Dongwei Li, Weigang Ge, Zongxiang Nie, Mengge Lyu, Jun A, Yingrui Wang, Yingdan Chen, Zhenhai Fu, Nan Xiang, Lu Li, Fengchao Yu, Guo Ci Teo, Alexey I. Nesvizhskii, Meng Wang, Michael P. Snyder, Ben C. Collins, Qi Xiao, Ruedi Aebersold, Fei Xu, Hui Yang, Sijia Zhang, Yi Han, Yi Zhu, Yong Ji, Yan Li, Tiannan Guo
A detailed, spatially resolved quantitative map of the human proteome is essential for a deeper understanding of human biology and disease1,2,3,4. Here we present a comprehensive human proteomic landscape, generated by profiling more than 13,000 proteins across 2,856 samples using data-independent acquisition mass spectrometry. The dataset spans 58 major tissue types, 251 specific tissue subtypes and 25 distinct carcinomas. This resource enables the depiction of spatially resolved proteome trajectories across tissue types and physiological states, including fetal, tumour, adjacent non-tumour and healthy adult tissue, thereby providing insight into both developmental processes and oncogenic progression. Furthermore, quantitative proteomics comparisons across diverse tissue types and states facilitate the indication of organ-specific toxicity, the identification of repurposable anticancer drug candidates and the prioritization of therapeutic targets for cancers. This study establishes a quantitative resource for navigating the proteome in the human body and in common cancers.
Proteomics, Systems analysis, Target identification, Tumour biomarkers
Lethal plague outbreaks in Lake Baikal hunter-gatherers 5,500 years ago
Original Paper | Archaeology | 2026-06-16 20:00 EDT
Ruairidh Macleod, Frederik V. Seersholm, Bianca De Sanctis, Angela Lieverse, Adrian Timpson, Rick Schulting, Jesper T. Stenderup, Charleen Gaunitz, Lasse Vinner, Olga Ivanovna Goriunova, Vladimir Ivanovich Bazaliiskii, Sergei V. Vasilyev, Erin Jessup, Yucheng Wang, Christopher Bronk Ramsey, Mark G. Thomas, Russell Corbett-Detig, Astrid K. N. Iversen, Andrzej W. Weber, Martin Sikora, Eske Willerslev
Plague is among the most devastating diseases in human history1. However, early strains of the plague-causing bacterium Yersinia pestis lacked virulence factors that are required for the bubonic form until around 3,800 years ago2,3. Consequently, the morbidity and mortality of early plague strains remain unclear. Here we describe early plague strains that are associated with two phases of outbreaks among mid-Holocene hunter-gatherers near Lake Baikal in southeast Siberia, beginning from about 5,500 years ago. These outbreaks occur across four hunter-gatherer cemeteries, with a 39% detection rate for plague infection. By reconstructing kinship pedigrees, we show that small familial groups were affected, consistent with human-to-human spread of disease, and that the first outbreak occurred within a single generation. The infections appear to have resulted in acute mortality, especially among children (aged 8 to 11 years). We further note functional differences, including in the ypm superantigen locus, which is also present in present day Yersinia pseudotuberculosis. The new strains diverge ancestrally to known Y. pestis and constrain the timing of its emergence, indicating that this happened before approximately 5,700 years ago. These findings show that plague outbreaks happened earlier than previously thought and were indeed lethal. We contend that the occurrence of outbreaks among mid-Holocene hunter-gatherer communities well outside the sphere of Late Neolithic Europe challenges the notion that higher population densities and lifestyle changes during the Neolithic agricultural transition were prerequisites for plague epidemics.
Archaeology, Evolutionary biology, Infectious diseases
Mapping the neuronal building blocks of human language with language models
Original Paper | Language | 2026-06-16 20:00 EDT
Jing Cai, Yoav Kfir, Mohsen Jamali, Hesen Huang, Young Joon Kim, Sydney S. Cash, Ziv M. Williams
Humans can convey new and highly diverse information through language. This ability to form and combine words into elaborate phrases and sentences enables us to express inexhaustible meanings and is fundamental to human cognition1,2,3,4,5. However, understanding the microscopic cellular building blocks and cortical landscape that precisely underlie human language has remained a challenge. Here we used wide-scale single-neuronal recordings combined with natural language processing models to identify fine-grained linguistic representations across the human frontotemporal cortex during language production. We find that, whereas certain neurons represented the detailed grammatical relationships between words or their parts of speech, others tracked the sentences’ higher-order syntactic structure, their phrase transitions and sequence. Collectively, these neurons reliably captured the words’ syntactic and semantic properties but also dynamically incorporated their specific sentence contexts, therefore enabling them to encode information combinatorially and at highly granular levels of detail. We show how these cell populations were locally organized and how their microscale representations differed from that of their wider field potential patterns. We also show how these neurons were distributed broadly across the frontotemporal cortex, but how their ability to encode linguistic information was left-lateralized and varied between cortical regions. Together, these findings identify some of the most basic cellular building blocks by which linguistic information is encoded in humans and begin to define the cortical landscape of language at a combined micro (cellular), meso (local population) and macro (regional) scale.
Language, Neural decoding
Towards autonomous medical artificial intelligence agents
Original Paper | Computational science | 2026-06-16 20:00 EDT
Dyke Ferber, Lars Hilgers, Christiane Höper, Benedict Kinny-Köster, Jan-Niklas Eckardt, Katharina Egger-Heidrich, Marius Bill, Martin M. K. Schneider, Jan Clusmann, Lejla Kadric, Marcel Oehme, Maximilian Mayrhofer-Schmid, Alexander Oeser, Georg Wölflein, Isabella C. Wiest, Jan Moritz Middeke, A. John Iafrate, Daniel Truhn, Dirk Jäger, Jakob Nikolas Kather
Large language models (LLMs) show great potential for clinical decision-making, yet most applications remain narrow, task-specific chat tools rather than systems integrated into clinical workflows1,2. However, building physician copilots will require models that operate within the electronic health record (EHR), with governed access to patient data and the ability to initiate permitted EHR actions within defined safety constraints. Yet it remains unproven whether such a system can manage patient cases with physician-level performance. Here we show that MIRA (Medical Intelligence for Reasoning and Action), an autonomous artificial intelligence agent operating in a sandboxed EHR environment, can navigate a large clinical action space to obtain patient histories; order and interpret laboratory, imaging and microbiology tests; generate differential diagnoses; and formulate treatment plans such as prescribing medications, scheduling surgical procedures and planning admissions. In simulations on real patient cases spanning multiple diagnoses, MIRA outperformed physicians in diagnostic accuracy and made guideline-concordant, medication-safe and appropriate admission decisions. Compared with previous LLM applications that addressed isolated subtasks or provided free-text advice, these results suggest that an EHR-integrated artificial intelligence agent can turn clinical intent into structured, actionable EHR operations, possibly making it a more effective decision-support partner for physicians. Further work is needed to establish generalization, safety and governance through prospective, real-world studies.
Computational science, Health services, Translational research
CHPO coordinates chilling recovery and nitrogen use in rice
Original Paper | Abiotic | 2026-06-16 20:00 EDT
Jie Cao, Yunyuan Xu, Zhitao Li, Jingdan Han, Qian Qian, Song Ge, Hong Wang, Wei Luo, Kang Chong
Global rice production faces mounting challenges from abnormal temperature fluctuations and nitrogen-fertilizer-driven environmental pollution1,2,3,4,5,6,7. Developing varieties that balance chilling resilience and nitrogen-use efficiency (NUE) offers a promising solution, but the molecular networks coordinating these traits remain poorly understood. Here we identify CHILLING PHOENIX (CHPO), a major gene underlying the quantitative trait locus shared by both chilling tolerance and resilience. It encodes a MYB transcription factor that acts as a key regulator coordinating post-chilling recovery with nitrogen use in rice. Natural variation in a GCG-repeat-encoded polyalanine tract alters CHPO DNA-binding preference and redirects regulatory outputs between the japonica-type (CHPOjap) and indica-type (CHPOind), causing opposing effects on chilling tolerance and resilience. This allelic variation is shaped by domestication selection, with the CHPOjap allele probably derived from Chinese wild rice. CHPOjap directly targets OsTCP19 and OsNRT2.4 to fine-tune NUE, thereby enhancing chilling tolerance and resilience. These findings provide a mechanistic framework for a chilling-induced high-nitrogen-utilization module that alleviates the damage caused by chilling stress, and a potential molecular design strategy for breeding rice varieties with both chilling resilience and high NUE at the recovery stage.
Abiotic, Natural variation in plants, Plant breeding, Plant development
Optical metasurfaces for general vision processing on the edge
Original Paper | Applied optics | 2026-06-16 20:00 EDT
Jiayong Peng, Mingcheng Luo, Yuxi Han, Siying Wu, Hongsheng Li, Bhavin J. Shastri, Chester Shu, Qi Dou, Yang Chai, Chaoran Huang
Large-scale artificial intelligence (AI) models achieve notable performance in computer vision but require substantial computational resources, limiting their deployment on edge devices1,2. Optical neural networks (ONNs) promise reduced latency and energy consumption by making use of the inherent parallelism of light3. However, present ONNs struggle to scale and are confined to simple tasks, owing to the challenges of replicating exact algebraic operations of digital models using physical (analogue) systems. This work introduces a new paradigm that directly embeds core computer vision principles, including similarity-based recognition, attention-guided perception and detail-context fusion, into a large-scale optical metasurface. By unifying optical physics with these computer vision fundamentals, we develop a photonic-electronic engine that overcomes scalability and generality barriers, enabling high-accuracy, general-purpose computer vision at the edge. The resulting system combines a 41-million-parameter optical metasurface front end with a co-designed, ultraefficient 87,000-parameter digital back end, outperforming many digital models with tens of millions of parameters across object detection, segmentation, 3D reconstruction and video understanding. We build a deployable prototype and demonstrate real-time edge visual processing in natural scenes. This work represents a path towards practical optical computing for general vision tasks in complex natural environments, enabling a new paradigm for low-energy, low-latency, real-time on-device vision intelligence.
Applied optics, Optical physics
Visualizing the impact of quenched disorder on 2D electron Wigner solids
Original Paper | Electronic properties and materials | 2026-06-16 20:00 EDT
Zhehao Ge, Conor Smith, Zehao He, Yubo Yang, Qize Li, Ha-Leem Kim, Ziyu Xiang, Jianghan Xiao, Wenjie Zhou, Salman Kahn, Aining Hu, Melike Erdi, Rounak Banerjee, Takashi Taniguchi, Kenji Watanabe, Seth Ariel Tongay, Miguel A. Morales, Shiwei Zhang, Feng Wang, Michael F. Crommie
Electron Wigner solids (WSs)1,2,3,4,5,6,7,8,9,10,11,12 provide an ideal system for understanding the competing effects of electron-electron and electron-disorder interactions, a central unsolved problem in condensed matter physics. Progress in this topic has been limited by a lack of single-defect-resolved experimental measurements as well as accurate theoretical tools to enable realistic experiment/theory comparison. Here we overcome these limitations by combining atomically resolved scanning tunnelling microscopy (STM) with neural-quantum-state quantum Monte Carlo (NQS-QMC) simulation of disordered 2D electron WSs to discover new disorder-induced physical regimes of correlated electron behaviour. STM was used to image the electron density (ne)-dependent evolution of electron WSs in gate-tunable bilayer MoSe2 (BL-MoSe2) devices with varying long-range (nLR) and short-range (nSR) disorder densities. These images were compared with NQS-QMC simulations using realistic disorder maps extracted from experiment, thus allowing the roles of different disorder types to be disentangled. We identify two distinct physical regimes for disordered electron WSs that depend on nSR. For nSR ≲ ne, the WS behaviour is dominated by long-range disorder and features extensive mixed solid-liquid phases, a new type of local re-entrant melting/crystallization and prominent Friedel oscillations. By contrast, when nSR ≫ ne, these features are suppressed and a more robust amorphous WS phase emerges that persists to higher ne, highlighting the importance of short-range disorder in this regime. Our work establishes a powerful framework for studying disordered quantum solids through a combined experimental-theoretical approach.
Electronic properties and materials, Phase transitions and critical phenomena, Quantum fluids and solids, Scanning probe microscopy, Two-dimensional materials
Cucurbituril-based anion-conducting membranes with supramolecular nanopores
Original Paper | Electrocatalysis | 2026-06-16 20:00 EDT
Ziang Xu, Dongcheng Lin, Haoyu Yin, Qingqing Feng, Fabrizia Foglia, Yihan Zhen, Adam Morris, Quentin Berrod, Maobin Pang, Lida Huang, Jing Liu, Jiekang Tian, Xiaonan Wang, Chunming Yang, Xingchen Tang, Xi Zhang, Baoguo Wang, Haotian Wang, Kai Liu
Nanoporous anion-conducting membranes have gained considerable interest for their potential to reduce resistance in electrochemical devices1,2,3,4. Current pore-forming methods, such as backbone engineering through polymers of intrinsic microporosity5,6 or covalent organic and metal-organic frameworks7,8, however, suffer from limited structural control, mechanical fragility or demanding synthesis. Here we establish a supramolecular strategy that overcomes these limitations by constructing uniform, dynamic nanopores. Co-assembly of the rigid macrocyclic host cucurbit[7]uril with the cationic polymer guest quaternized poly(piperidinium-terphenyl) yields a robust network of nanometre-scale channels while simultaneously enhancing mechanical and chemical stability. The dynamic host-guest interactions allow the pore structure to fluctuate on picosecond and angstrom scales. This transient environment supports low-friction hydroxide migration through a Grotthuss mechanism, producing a marked enhancement in ionic conductivity. This bottom-up design principle provides a versatile new tool for molecularly engineering transport pathways and promises to advance electrochemical reactors with respect to energy efficiency, operational stability and the production of high-purity products.
Electrocatalysis, Energy
Nature Materials
Operando microscopy for neuromorphic hardware
Review Paper | Materials for devices | 2026-06-16 20:00 EDT
Yimei Zhu, Alex Frano, Shriram Ramanathan
Microscopy techniques can uncover the physical properties and dynamic behaviours of materials, driving the discovery of emergent phenomena and guiding the design of next-generation computing hardware. As artificial intelligence becomes pervasive, the demand for high-performance materials to support sustainable information technologies is growing. This Review highlights state-of-the-art imaging from electron and X-ray to optical techniques to probe the dynamics of neuromorphic materials, including operando characterization of devices. We examine design principles for neuromorphic materials, along with obstacles that hinder their development. Emphasis is placed on spatially and temporally resolved approaches that capture state changes including phase transitions, ferroic switching and spin-wave propagation that emulate biological components such as neurons, synapses and their connectivity. We discuss challenges in operando characterization and the integration of artificial intelligence-driven analysis for feedback-guided material discovery. Finally, we outline opportunities for real-time imaging of neuromorphic systems, paving the way towards adaptive, brain-inspired hardware.
Materials for devices, Nanoscience and technology
Nature Physics
Nanoscale strain wave generation by a piezoelectric grating from polar vortices
Original Paper | Ferroelectrics and multiferroics | 2026-06-16 20:00 EDT
Kook Tae Kim, Peter Meisenheimer, Boo Hyun Cha, Ilwan Seo, Hoyoung Jang, Sae Hwan Chun, Dogeun Jang, Minseok Kim, Hyeongi Choi, Sang-Youn Park, Byungjune Lee, Jaeku Park, Intae Eom, Kyung Sook Kim, Hyun Hwi Lee, Woo-Suk Noh, Yongseong Choi, Jong-Woo Kim, Joerg Strempfer, Se Young Park, Ramamoorthy Ramesh, Dong Ryeol Lee
Nanostructures formed by spontaneously broken symmetry have provided new ways to manipulate quantum states. Specifically, topological structures with periodic spatial ordering, such as polar vortices and skyrmions, can be ideal hosts for creating engineered responses in both spatial and frequency domains. So far, however, only a few examples of such hierarchical engineering have been reported in the literature. Here we demonstrate that the spatially modulated piezoelectric response of a polar vortex structure can create strain waves with a characteristic nanoscale wavefront. Using time-resolved pump-probe resonant X-ray scattering and diffraction measurements, coupled with dynamical phase-field simulations, we show that the piezoelectric modulation of the spontaneously formed polar vortex crystal functions as an acoustic diffraction grating. This system converts incoming laterally uniform strain waves into outgoing waves with a characteristic sub-terahertz frequency, driven by an intrinsic excitation of the polar vortex crystal. Moreover, our phase-field simulations suggest that the dynamic mechanical displacements exhibiting vortex textures are generated from both space- and time-varying piezoelectric responses. Our findings illustrate a new method for generating nanoscale strain waves with unique spatial textures by tuning the hierarchical order of polar topologies to engineer new collective modes, allowing for a wide range of control through the topological lattice.
Ferroelectrics and multiferroics
Microscopic signatures of an imaginary charge density wave in a kagome metal
Original Paper | Electronic properties and materials | 2026-06-16 20:00 EDT
S. Suetsugu, F. Hori, M. Shibata, S. Kitagawa, K. Ishida, T. Asaba, S. Nakazawa, Q. Li, H. -H. Wen, T. Shibauchi, H. Kontani, Y. Matsuda
Loop current order has long been proposed as an unconventional electronic state arising from spontaneous symmetry breaking through the formation of microscopic electric current loops. The microscopic origin of these currents stems from imaginary hopping terms, conceptualized as an imaginary charge density wave. Despite extensive investigations, particularly in the context of the pseudogap state in high-temperature cuprate superconductors, its existence remains highly controversial. Here we demonstrate site-selective spectroscopic signatures of a pure imaginary charge density wave in the kagome non-magnetic metal CsV3Sb5. Nuclear quadrupole resonance spectra reveal anomalous broadening around a characteristic temperature of 120 K, which coincides with the nematic transition well above the real charge density wave order. In a magnetic field, the spectra exhibit antisymmetric lineshapes, demonstrating that this broadening purely originates from magnetic effects rather than from electric quadrupolar effects associated with charge order fluctuations. The observed lineshapes are quantitatively consistent with local fields induced by loop currents, indicating spontaneous time-reversal symmetry breaking. This microscopic evidence of a pure imaginary charge density wave suggests a distinct form of quantum order and extends our understanding of exotic electronic states in quantum materials.
Electronic properties and materials, Magnetic properties and materials
arXiv
Excitonic Condensation in an Asymmetric Electron-Hole Biwire
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Gautam Shah, Vinod Ashokan, N. D. Drummond, K. N. Pathak
We study a mass-asymmetric one-dimensional electron-hole biwire system at zero temperature using the diffusion quantum Monte Carlo method. Pair correlation functions and condensate fraction are obtained over a wide range of carrier densities $ r_{\rm s}$ and interwire separations $ d$ , allowing us to construct the phase diagram. We identify regimes corresponding to a two-component electron-hole plasma, an excitonic fluid with quasicondensation, and a Wigner-correlated phase at various densities. Owing to reduced dimensionality, strong electron-hole correlations favor excitonic quasicondensation even in the high-density limit, persisting down to $ r_{\rm s} = 0.3$ a.u. These results provide a microscopic characterization of correlation-driven phases in electron-hole systems in one dimension.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el)
Chiral Phonons Enable Ultrafast Magnetization Switching via Magnetoelastic Coupling
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Weiwei He, Muhammad Hamza Asim, Mara Strungaru, Roy Chantrel, Min Yi, Oksana Chubykalo-Fesenko
Phonons are desirable for current-free energy-efficient spin manipulation and harnessing their chirality to achieve ultrafast magnetization switching remains actively pursued. Here we demonstrate that terahertz-driven chiral phonons enable faster magnetization switching than linear phonons through the purely magnetoelastic coupling that transfers both energy and angular momentum. Only one phonon handedness efficiently transfers angular momentum to the spin system, which we explain by a large fictitious kinematic Barnett-like field at THz frequencies that destabilizes spin precession for the opposite chirality. Considering different regions of the spinwave spectrum, we find that switching conditions can be realized near the {\Gamma}-point where strong energy transfer and spinwave excitation dominate, and near the P-point which offers minimal energy loss. Our results establish phonon chirality as a decisive and previously overlooked parameter in spin-lattice dynamics within the magnetoelastic coupling mechanism, offering a promising avenue for ultrafast low-energy spintronic devices.
Materials Science (cond-mat.mtrl-sci)
Derivation of height field theory for the two-dimensional classical dimer model from a Grassmann-integral representation
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
The classical dimer model on bipartite lattices hosts a Coulomb phase, characterized by algebraic correlations and topological order. Its long-wavelength properties can be described by the fluctuations of a vector field with zero divergence, which, in two dimensions, is equivalent to a continuum height model. We show how this field theory can be derived constructively for both square and honeycomb lattices, starting from an exact representation of the dimer model in terms of Grassmann integrals. Taking the continuum limit gives a massless Dirac fermion in two-dimensional Euclidean space, which, using bosonization in the path integral representation, maps exactly to the well-known height field theory, incorporating the relationship between its boundary discontinuity (or “tilt”) and the flux. By including source terms coupling to the flux density and the local valence-bond-solid order parameter, which we show are the only ones required to describe the asymptotic long-distance correlations, we derive expressions for the dimer observables in terms of the height.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th)
28 pages, 5 figures
Superconductivity from emergent dipolar interactions in a fractionalized Fermi liquid
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Mina-Lou Schleith, Arthur Bril, Nick Bultinck
Starting from the spin-fermion model or Hertz-Millis theory describing electrons coupled to anti-ferromagnetic spin fluctuations we develop a theory to describe the transition from a fractionalized Fermi liquid into a $ d_{x^2-y^2}$ superconductor. We focus on small electron doping on top of the half-filled state. The doped electrons enter the system as spinon-chargon bound states, which form a small, reconstructed Fermi surface. The bound states are neutral under the emergent U(1) gauge symmetry of the fractionalized Fermi liquid, but interact via a dipolar two-body potential. We show that because of the projective action of translation symmetry on the spinons and chargons, the Fourier components of this repulsive dipolar interaction are peaked at the anti-ferromagnetic wave vector, thereby providing a robust microscopic mechanism for $ d_{x^2-y^2}$ pairing in a fractionalized metal.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Exotic magnetism and persistent spin dynamics in a frustrated Jeff = 1/2 triangular lattice antiferromagnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
M. Barman, K. Jaksetič, M. Pregelj, M. D. Le. P. J. Baker, A. Zorko, P. Khuntia
The delicate interplay between competing degrees of freedom, anisotropy, and frustration-induced strong quantum fluctuations in pseudospin-$ J_{\rm eff}=1/2$ rare-earth triangular-lattice antiferromagnets offers a promising platform for the experimental realization of exotic states with nontrivial low-energy excitations. Here, we present thermodynamic, inelastic neutron scattering (INS), and muon spin relaxation ($ \mu$ SR) investigations of the frustrated magnet K$ _3$ NdTe$ _2$ O$ 9$ , in which Nd$ ^{3+}$ ions constitute a structurally perfect triangular lattice with no detectable site disorder. The experiments reveal the realization of a Kramers doublet ground state with $ J{\rm eff}=1/2$ moments, well separated from the first excited state, which interact antiferromagnetically with an exchange interaction of $ \sim$ 0.6 K between the Nd$ ^{3+}$ moments in the triangular plane. The absence of oscillations and the so-called 1/3 plateau in the zero-field $ \mu$ SR asymmetry down to 50 mK rules out long-range magnetic ordering and spin freezing on the $ \mu$ SR time scale, respectively. The temperature dependence of the zero-field $ \mu$ SR relaxation rate is well described by the Orbach relaxation mechanism, indicating the existence of fluctuating moments in the ground state of this frustrated magnet. Our results demonstrate exotic magnetism and persistent spin dynamics down to 50 mK. These observations establish this new family of frustrated rare-earth triangular-lattice antiferromagnets as a promising venue for the experimental realization of nontrivial quantum states with exotic low-energy excitations.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Hybrid Ferromagnet-SNSPDs: Single photon induced order-to-disorder transition in ferromagnets coupled to thin film superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Leif Bauer, Daien He, Sathwik Bharadwaj, Zubin Jacob
The development of midwave and longwave infrared single photon detectors is crucial for their emerging applications in spectroscopy, remote sensing, exoplanet detection, and free space quantum communications. However, existing sensors need to be operated at extremely low temperatures (0.08-0.9K) to reduce dark noise and hence require the use of advanced cryogenics such as dilution refrigerators or $ ^3$ He cryogens, significantly limiting applications. Here we propose a vortex-engineering approach based on a hybrid phase transition in a ferromagnet/superconductor bilayer to increase the operating temperature of infrared single photon detectors up to 3.75K. We show that the introduction of a ferromagnetic layer produces a local magnetic field which impedes vortex crossing in the superconductor, reducing dark noise. When a single photon is incident, the photon-induced hotspot causes an order-to-disorder transition in the ferromagnet, leading to a vortex-induced phase transition in the superconducting layer. By engineering the ferromagnet’s Curie temperature to be close to the device’s operating temperature, single photon sensitivity can be achieved at increased operating temperatures. We predict at midwave/longwave infrared wavelengths (3-14$ \mu$ m) the operating temperature can be raised to 3.25-3.75K, enabling significantly simpler cooling systems.
Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
11 pages, 6 figures
Why dimensional analysis works: general classification of self-similarity based on scale-invariance
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
In this work, we formulate self-similarity from the perspective of scale invariance, where a self-similar form is understood as the transformation of a function into a form invariant under scale transformations. By applying this formulation to physical parameters, which consist of numerical values and units, it is demonstrated that dimensional analysis works for physical problems because scale invariance is partially shared between units and physical parameters. This naturally leads to the distinction between similarity of the first kind and similarity of the second kind according to whether the scale functions induced by units and those associated with physical parameters are equivalent or not. Self-similar solutions of the second kind can be further classified according to whether the power exponents of the similarity parameters include functions of dimensionless numbers. This leads to the conclusion that there are three kinds of self-similar solutions. The present work provides a unified framework for understanding dimensional analysis and a universal classification of self-similarity in physical problems.
Statistical Mechanics (cond-mat.stat-mech)
31 pages, 5 figures
Machine learning insights into band gap properties in halide-based perovskites
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Chadawan Khamdang, Mengen Wang
Halide perovskites show great promise for applications in optoelectronic devices. The lead-free perovskites are attracting increasing interest due to their low toxicity and motivate the exploration of alternative compositions and structures, including A$ _2$ BX$ _6$ , A$ _2$ BB$ ^\prime$ X$ _6$ , A$ _3$ B$ _2$ X$ _9$ , and A$ _4$ BX$ _6$ . Accurate predictions of a wide range of band gap energies are important for designing new materials. It is also desired to generate a direct relationship between the structural and elemental descriptors and the band gap energies. In this work, we develop machine learning models to predict band gap energies across various types of halide perovskites based on atomic and structural properties. Algorithms including ensemble tree-based methods, random forest regression (RFR), gradient boosted regression trees (GBRT), and extreme gradient boosting (XGB) showed strong predictive accuracy. We also analyzed feature importance to identify key descriptors, including B-site and X-site elemental properties, as well as the number of A- and B-site atoms, as primary factors influencing band gap energies. These results improve our understanding of the ML models and provide guidance for designing new halide perovskite materials.
Materials Science (cond-mat.mtrl-sci)
How twist angle inhomogeneity masks the BKT transition and the order parameter symmetry
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Ilaria Maccari, Louk Rademaker, Giulia Venditti
Two-dimensional superconductors, including twisted multilayer graphene, should exhibit a BKT transition, and the $ T$ -dependence of the superfluid stiffness should distinguish between nodal or gapped order parameter symmetries. However, this picture dramatically changes when spatially correlated disorder is taken into account. Such correlations naturally arise in moiré systems due to twist angle inhomogeneities, which we model using elasticity theory. Using a random impedance network based on realistic disorder in the local $ T_c$ , we show that the finite-frequency conductance reveals a smeared percolative transition instead of a BKT transition. At low temperatures, the disorder can effectively obscure the distinction between nodal and fully gapped superconducting order parameters. We propose that the real part of the conductivity can be used as a key diagnostic observable to probe the relevance of correlated disorder.
Superconductivity (cond-mat.supr-con), Disordered Systems and Neural Networks (cond-mat.dis-nn), Strongly Correlated Electrons (cond-mat.str-el)
17 pages, 6 figures
Kohn–Luttinger Superconductivity in Flat Chern Bands
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Nianlong Zou, Cheng Xu, Yafis Barlas, Yang Zhang
Recent observations of superconductivity near correlated topological phases in flat bands suggest a facile link between flat-band geometry and electron pairing. In this work, we reveal a geometry-driven Kohn–Luttinger mechanism in which Landau-level-like form factors align the attractive lobe of the RPA-screened Coulomb interaction with the form-factor peak, generating an anomalously strong attractive channel near local band extrema. Using the Skyrmion lattice model as a minimal realization, we show that for spin-unpolarized pairing the form-factor magnitude enforces an emergent momentum-space translational symmetry and selects an extended-$ s$ instability concentrated at small Fermi pockets, while for spin-polarized pairing the form-factor phase drives chiral $ p$ - and $ f$ -wave order without invoking spin fluctuations. The band-extrema enhancement persists in higher Landau-level analogs and survives finite-temperature screening and Berezinskii–Kosterlitz–Thouless phase fluctuations. Our work establishes quantum geometry as a key organizing principle for unconventional pairing in flat Chern bands.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)
6 pages, 4 figures, plus Supplemental Material
Physics-Informed Attention Mechanism and Generalization Capability of Deep Learning-Based Grain Growth Evolution Prediction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Pungponhavoan Tep, Marc Bernacki
Machine Learning (ML) models for grain growth prediction are typically trained on idealized synthetic data, yet practical applications require generalization to conditions outside the training distribution. This study evaluated the Out-Of-Distribution (OOD) generalization capability of the trained model from our previous study across three test cases, including experimental microstructures, microstructures characterized by a bimodal grain size distribution, and abnormal grain growth. To further probe whether physics-informed architectural design could improve robustness under these different conditions, a boundary-masked attention mechanism was proposed specifically for grain growth, constraining attention to grain boundary pixels. Both the baseline and the proposed physics-informed attention model were evaluated without retraining or fine-tuning on the OOD data. Both models successfully generalized to all three test cases, yet the boundary-masked attention mechanism provided substantial improvements, with the most notable gains for microstructures characterized by a bimodal grain size distribution, where Structural Similarity Index Measure (SSIM) improved from \num{0.6221} to \num{0.7609} and mean grain size ($ \overline{R}$ ) error decreased from \SI{8.75}{\percent} to \SI{3.57}{\percent}. The attention heatmap analysis revealed that the boundary-masked attention model learned to concentrate attention on large grain boundaries in a manner consistent with curvature-driven grain growth physics, emerging from training without being explicitly encoded into the architecture. These results indicate that models trained on synthetic data can generalize to diverse OOD conditions without retraining, and that physics-informed attention may improve accuracy when the boundary morphology matches the training domain.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
Antisite-disorder driven tuning of magnetic properties and exchange-bias in Nd${2-x}$Sr${x}$CoMnO$_{6-δ}$ $(0 \leq x \leq 1)$ ($δ\sim 0.5$) double perovskites
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
Kazi Parvez Islam, Jayjit Kumar Dey, Sourav Chowdhury, Samyabrata Paria, Flora Banerjee, Suryakanta Mishra, Suman Kalyan Samanta, Moritz Hoesch, Robert Dankelman, Indu Dhiman, Debraj Choudhury
We demonstrate precise control of exchange bias (EB) in the Nd$ _{2-x}$ Sr$ _x$ CoMnO$ _{6-\delta}$ ($ 0 \leq x \leq 1$ ) double-perovskite series through Sr$ ^{2+}$ induced hole doping, unveiling a remarkable transition between normal and inverse EB states. Employing neutron powder diffraction and X-ray absorption spectroscopy, we reveal a structural evolution from a B-site-ordered monoclinic ($ P2_1/n$ ) phase to a disordered rhombohedral ($ R\overline{3}c$ ) phase with increasing $ x$ , accompanied by a shift in the effective Co valence from +2 toward +3, while the Mn valence remains essentially unchanged. DC magnetization measurements indicate a gradual suppression of ferromagnetism with hole doping, whereas AC susceptibility measurements at $ x = 0.75$ reveal pronounced cluster-glass behavior and the highest EB field of $ \sim 4$ kOe at 8 K under a 6 T cooling field. After correcting for minor-loop effects, we identify robust inverse EB at $ x = 0.75$ , persisting even under a cooling field of 6 T. We attribute this phenomenon to competing ferromagnetic–antiferromagnetic and ferromagnetic–glassy interfaces, governed by strong magnetic frustration and the magnetocrystalline anisotropy associated with rare-earth 4$ f$ electrons. These findings elucidate the pivotal role of doping-induced structural and magnetic competition in tailoring EB behavior in rare-earth double perovskites, providing new insights for the design of advanced magnetic materials.
Strongly Correlated Electrons (cond-mat.str-el)
28 pages, 20 figures
Spin effects in the particle current of Bose-Einstein condensates in synthetic gauge fields
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-06-17 20:00 EDT
Hugo Bencomo Martín, Antonio Muñoz Mateo
Although spin is not a relativistic quantity, its effects are not always manifestly captured within non-relativistic theoretical frameworks. We report on one of these effects: the spin term in the particle current density, which could be observed in the setup of a synthetic Hall system made with non-relativistic Bose-Einstein condensates of pseudospin-1/2 bosonic particles. By tuning the interaction strength, the system can show how the spin term in the particle current is needed for the local matching of classical drift velocity in the ground state of the non-interacting system, whereas for increasing interactions the spin-to-orbital current ratio decreases. In either case, since the overall particle velocity changes with the spin term contribution, so does its circulation in a loop, which in turn has physical consequences for its relationship with the Aharonov-Bohm phase shift.
Quantum Gases (cond-mat.quant-gas)
8 pages, 4 figures
Stochastic Thermodynamics of Score Matching in Diffusion Models
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-06-17 20:00 EDT
Xuehao Ding, H. T. Quan, Yuhai Tu
Score-based diffusion models are a powerful class of generative AI systems capable of sampling from complex, high-dimensional probability distributions. Their dynamics consist of a forward diffusion process that transforms data into noise and a learned reverse process that reconstructs data by reversing the probability flow. Here, we develop a stochastic thermodynamic framework for diffusion models and their score-matching objective. We introduce a trajectory-dependent quantity, time-asymmetry entropy production (TAEP), defined from the forward and reverse diffusion dynamics, and show that it obeys exact fluctuation theorems. Remarkably, Hyvärinen’s implicit score-matching kernel emerges naturally as a fluctuating component of TAEP, while the average TAEP is exactly proportional to the score-matching objective. We further show that fluctuations of TAEP quantify sampling unevenness and provide a thermodynamic measure of data-manifold coverage. These results yield a quantitative explanation for the superior sampling diversity of diffusion models and reveal a thermodynamic mechanism by which stochastic gradient descent favors flatter, more generalizable solutions. By uncovering the entropic nature of score matching, our work establishes fundamental statistical-mechanical principles underlying diffusion-based generative AI.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
General Method for Evaluation of Stop-Bands of Periodic Structures with Symmetric Unit Cells
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Alexander Hvatov, Mariia Krasikova, Aleksandra Pavliuk, Steffen Marburg
The mirror symmetries of a periodic unit cell are exploited to decompose the standing-wave eigenproblem at the high-symmetry vertices of the Brillouin zone into four independent sub-problems on a quarter-cell, each governed by Neumann (sound-hard) or Dirichlet (sound-soft) boundary conditions. Sorting and pairing the resulting eigenfrequencies by index along each segment of the irreducible Brillouin zone boundary yields an explicit formula for the stop-band intervals without computing the full dispersion diagram. The decomposition is exact, following directly from the representation theory of the little group at each high-symmetry point. It applies to any unit cell whose material distribution is invariant under the mirrors normal to the cell faces. The method is validated on two configurations: a phononic crystal of lead cylinders in an epoxy matrix, analyzed using the plane-wave expansion, and a lattice of coupled C-shaped Helmholtz resonators, analyzed using finite-element analysis. For both systems, the reconstructed stop-band boundaries agree with the full Floquet dispersion calculation to within 1% for the lowest bands, requiring eigenvalue solutions at only three discrete wavevectors. Avoided crossings within a Brillouin zone segment can cause bands to exhibit non-monotone behavior, rendering the pairing rule approximate; the spectral conditions for this are identified. Flat bands common to both boundary-condition types are identified as bound states in the continuum.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Computational Physics (physics.comp-ph)
Tunable Superconductivity in 1313-La$_3$Ni$_2$O$_7$: Suppressed under Compression and Possible $s^{\pm}$ Pairing under Tension
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Yang Zhang, Ling-Fang Lin, Adriana Moreo, Thomas A. Maier, Elbio Dagotto
Motivated by recent progress in the 1313-La$ _3$ Ni$ _2$ O$ _7$ nickelate thin films (Nie et al., Nature {\bf 652}, 628 (2026)), we systematically investigate the effects of both compressive and tensile strain in this system. Self-doping effects between the single-layer (SL) and trilayer (TL) blocks are observed in our studies in both cases, but are most pronounced under tensile strain. We find that superconductivity is unlikely to emerge in the 1313 film on the LSAO substrate even with further hole doping. Remarkably, within the random-phase approximation, under {\it tensile} strain, a robust $ s^{\pm}$ -wave pairing state emerges in the TL subsystem with sign changes between the small electron-like $ \sigma$ pocket at the $ \Gamma$ point and the small hole-like $ \gamma$ pocket at the M point. These pockets are connected by a wave vector close to $ (\pi,\pi)$ . Our calculations also suggest that superconductivity in 1313-LNO requires an optimally sized $ \gamma$ pocket, because an oversized $ \gamma$ pocket suppresses pairing formation. Overall, our results predict strain-dependent electronic reconstruction in 1313-La$ _3$ Ni$ _2$ O$ _7$ and provide guiding principles for engineering superconductivity under ambient pressure conditions.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
9 pages 5 figures
Room-temperature tuning and probing of Fermi polarons in atomically thin semiconductors on a plasmonic metasurface
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Tingting Wu, Francesca Maria Marchetti, Antonio Tiene, Antonio I. Fernández-Domínguez, Miao Qi, Zhe Wang, Lin Liu, Lei Wei, Francisco J. Garcia-Vidal, Mengxiao Chen, Qi Jie Wang, Yu Luo
The Fermi polaron, arising from interactions between a mobile impurity and a degenerate Fermi sea, is a many-body quasiparticle that provides a sensitive probe of strongly correlated electronic phases in atomically thin semiconductors. In doped transition-metal dichalcogenides, the attractive and repulsive polaron branches are well established in monolayers. However, extending active control and quantitative, branch-resolved probing to stacked geometries has remained elusive because spectral quenching and weak optical contrast restrict access to Fermi polaron signatures. Here, we integrate electron-doped WS$ _2$ flakes from monolayer to quadrilayer with a strain-tunable plasmonic metasurface, enabling high-contrast scattering readout at room temperature through coupling between Fermi polaron resonances and surface plasmons. This platform enables quantitative extraction of polaron branch spectral weights and coupling strengths across different layer numbers. We uncover a systematic thickness dependence of the spectral-weight distribution and demonstrate continuous and fully reversible spectral-weight transfer between attractive and repulsive branches in bilayers and quadrilayers, with near-complete transfer achieved in bilayers. By identifying layer number and strain as complementary control parameters for Fermi polarons, our results establish metasurface-enabled scattering spectroscopy as a practical route to resolve and manipulate many-body resonances in stacked van der Waals semiconductors, bridging idealized monolayer polaron physics and device-relevant architectures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
34 pages, 4 figures, Supplementary Materials
Dislocation-templated antiferromagnetic domains in epitaxial NiO
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Alexandra Fonseca Montenegro, Justin Michel, Fengyuan Yang, Roberto C. Myers
Controlling antiferromagnetic domains is essential for spintronics, yet deterministic manipulation remains challenging due to their lack of net magnetization. Here, we utilize scanning electron microscopy electron channeling contrast imaging (ECCI) to demonstrate a robust structural memory effect in epitaxial NiO/MgO(001), where antiferromagnetic twin-domain walls (DWs) are deterministically pinned at the nanoscale by interface dislocation networks. Thermal cycling across the Neel temperature reveals that while DW contrast completely vanishes in the paramagnetic phase, the features re-emerge at identical spatial locations upon cooling. Diffraction-vector-dependent ECCI demonstrates that domain contrast stems from localized rhombohedral magnetostrictive strain fields. By tracking a film thickness series from 23 to 60 nm, we resolve an explicit transition in oxide relaxation mechanics. A primary slip system initiates strain relaxation via interface misfit dislocations (MDs) tracking along <100>. At greater thicknesses, rising critical strain prompts threading segments to cross-slip onto secondary or higher-index planes, depositing a wavy network of zig-zag MD lines deviated toward <110>. Quantitative image analysis reveals that DW area fractions directly track the local density and spatial configuration of the evolving MD networks, providing a framework for defect-engineering antiferromagnetic textures using one-dimensional defects.
Materials Science (cond-mat.mtrl-sci)
5 pages, 4 figures
II. Exploring the role of the Crystal Electric Field in the vicinity of a Quantum Critical Point
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
Julian G. Sereni, Ivan Curlik, Slavo Gabani, Mauro Giovannini
Very low temperature thermdynamic properties of the Yb$ T_4M$ family of compounds are analyzed in a broad range of behavior including a quantum critical point QCP between magnetic and Fermi-liquid ground states GS. Doniach-Lavagna phase diagram limitations are improved by taking into account crystal electric field CEF splittings. The studied alloys: Yb$ T_{5-x}M_x$ (with $ T$ = Ni, Cu, and $ M$ = Cd, Mg, Pd, Au, Zn, Ag), allow to gain insight into the evolution of the GS behavior undergoing the QCP region as a function of chemical doping as control parameter. Three types of behaviors are recognized in this system: i) a magnetic one, with weak interactions at $ T_m\leq 1$ ,K and very low Kondo temperature of their respective doublets GS. Between $ T_m$ and $ T_q\approx 0.3$ ,K, quantum fluctuations start to dominate the scenario with the specific heat $ C_{4f}/T(T\geq T_q)$ showing $ T$ power law dependencies and a very heavy-fermion {\it plateau} below $ T_q$ . ii) beyond the QCP the typical non-fermi-liquid logarithmic $ T$ dependence: $ C_{4f}/T \propto \ln(T/T_0)$ and iii) at the non-magnetic limit, the alloys behave as valence-fluctuation systems with $ T_K$ overcoming the CEF splitting. With this experimental information, a more realistic phase diagram can be drawn around the QCP where the scenario is dominated by low lying quantum fluctuations, without $ C_{4f}/T|_{Lim T\to 0}$ divergences but a clear drop of its value.
Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 8 figures
Emergent Antiphase Stacking in a Transient Charge Density Wave
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
Jade Stanton, Gal Orenstein, Ryan A. Duncan, Gilberto A. de la Peña Muñoz, Yijing Huang, Viktor Krapivin, Quynh Le Nguyen, Samuel Teitelbaum, Anisha G. Singh, Roman Mankowsky, Henrik Lemke, Mathias Sander, Yunpei Deng, Christopher Arrell, Ian R. Fisher, David A. Reis, Mariano Trigo
Photoexcitation can induce novel states in materials that are inaccessible in equilibrium, a recent example being the light-induced charge density wave (CDW) observed in $ \text{LaTe}_3$ . Here, we investigate this transient CDW using infrared-pump x-ray-probe scattering at a free-electron laser, with high momentum and time resolution. We find that the transient CDW Bragg peak is broad in reciprocal space, indicating a highly disordered state. The ordering wavevector of the transient state is different from the equilibrium orders that develop in this class of materials - the transient peak appears near (2/7, 0, 0) reciprocal lattice units, whereas the equilibrium $ a$ order and $ c$ order occur at $ \approx (5/7, 0, 0)$ and $ (0, 0, 2/7)$ , respectively. The transient CDW is therefore distinct from the equilibrium $ a$ order, differing in the relative phase of the CDW displacement between the two equivalent nearly-square Te-Te nets in the conventional unit cell. Our work highlights how photoexcitation can access states with no equilibrium analog, and how x-ray scattering can provide microscopic insight into such elusive phases.
Strongly Correlated Electrons (cond-mat.str-el)
Robust Spin Splitting and Strain-Controlled Optical Response in Monolayer CrC2N4 for Valleytronic and Optoelectronic Applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Md. Samrat, Vivek Chowdhury, Sake Wang, Ahmed Zubair
Monolayer CrC2N4 recently emerged as a promising two-dimensional semiconductor, yet its spin-orbit-coupled (SOC) physics and strain-tunable optical response remained largely unexplored. Here, we investigated the electronic, valley, charge-transfer, and optical properties of pristine and biaxially strained monolayer CrC2N4 using first-principles calculations. The monolayer exhibited a direct band gap at the K/K’ valleys. SOC produced valley contrasting out-of-plane spin polarization, yielding a moderate valence band spin splitting of 51.9 meV and a small conduction band spin splitting of 1.7 meV. Orbital-resolved analysis showed that the edge states were mainly governed by Cr-d and N-p hybridization, while Bader analysis indicated polar-covalent bonding through charge transfer toward N atoms. Biaxial strain in the range of -4% to +4% tuned the band gap from 1.987 to 1.421 eV and drove an indirect-to-direct gap transition near -1% strain. Tensile strain enhanced the Berry curvature and red-shifted the optical response toward the visible-near-infrared region. These results suggested monolayer CrC2N4 as a promising platform for strain-engineered valleytronic and optoelectronic device applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
Characterization of ultrathin nickel films deposited by thermal laser evaporation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
David S. Catherall, Yifei Yan, Finley B. Donachie, Azmain A. Hossain, Austin J. Minnich
Thermal laser evaporation is a physical vapor deposition technique of increasing interest because of its ability to evaporate essentially any solid element, even the most refractory such as W. However, many films deposited by this method, especially non-epitaxial films, remain to be characterized; further, key system components such as the laser delivery system have not been described in detail. Here, we present the evaporation and characterization of ultrathin Ni films deposited with a home-built thermal laser evaporation system. The system employs a continuous-wave 1 kW fiber laser (1070 nm) focused to sub-millimeter diameter onto a Ni target rod mounted inside an ultrahigh-vacuum chamber. The laser heats the target to a temperature high enough to produce vapor for film deposition; for Ni, this temperature is around the melting point of 1725 K. We report the characterization of the surface roughness, composition, and room-temperature electrical properties of the films along with the design of the major components of our system. This work advances the growing consensus regarding the potential of thermal laser evaporation for thin film deposition and epitaxy and provides the necessary design information to facilitate broader adoption of the technique.
Materials Science (cond-mat.mtrl-sci)
15 pages, 6 figures
Appl. Phys. Lett. 23 February 2026; 128 (8): 081902
Vortex-Beam-Driven Dirac Materials: Impurity and Polarization Effects on Light-Induced Vortex and Edge States
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Trevor W. Walsh, Eric E. Caldwell, Nancy P. Sandler, Mahmoud M. Asmar
We study impurity scattering and polarization detuning in finite-size vortex-light-beam-driven massive Dirac systems. In finite geometries, circularly polarized vortex light opens a dynamical gap where topological edge states coexist with photoinduced multiply quantized vortex states. We analyze how finite-size effects, vorticity, and effective particle-hole symmetry manifest in the quasienergy spectrum, real-space states, and local density of states. We show that angular-momentum mixing due to localized impurities and impurity clusters reshape vortex states, while when produced by circular polarization, it leads to a gradual filling of the dynamical gap with bulk-derived states. Our results indicate that both vortex and edge signatures remain observable in the presence of impurities and realistic polarization deviations, providing guidance for experimental realizations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
16 Pages, 9 Figures
Operator ordering as an emergent gauge field in twisted bilayer graphene: singular spectral signatures at the magic angle
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Scanning-tunnelling spectroscopy at the AB and BA stacking points of magic-angle twisted bilayer graphene should reveal two asymmetric Van~Hove peaks separated by $ \Delta_{\mathrm{split}}\approx 171$ ~meV – a splitting absent from the standard Bistritzer–MacDonald spectrum. We show this signature arises naturally from the Hermitian ordering correction of the Dirac Hamiltonian with spatially varying mass, which generates an emergent Aharonov–Bohm flux of $ h/(2e)$ at each zero of the effective mass $ m_{\mathrm{eff}}(\mathbf{r})=w|f(\mathbf{r})|$ . In the chiral limit, the interlayer coupling is locally diagonalised by a spatially dependent unitary transformation; the ordering term $ H_{\mathrm{ord}}=-\tfrac{i}{2}\boldsymbol{\sigma}\cdot \nabla\ln m_{\mathrm{eff}}$ then develops a $ 1/r$ singularity at the AB/BA stacking points, where $ m_{\mathrm{eff}}$ vanishes. The splitting scales as $ \sqrt{\theta}$ – distinguishing it from correlation-driven gaps ($ \propto\theta$ or $ \propto 1/\theta$ ) – is gate-voltage independent, and is spatially localised within $ r_c\approx 2.1$ ~nm of each AB/BA point. Within the local asymptotic theory near the zeros of $ \mathrm{eff}$ , the ordering-corrected zero mode acquires parabolic-cylinder character $ D_{-1/2}$ . The spatially resolved AB/BA spectrum reported in recent STM studies of magic-angle TBG has not been analysed for two-peak structure and constitutes an immediate experimental test; the predicted cell-averaged broadening of $ \approx 14$ ~meV is consistent with the $ 16$ ~meV discrepancy between existing STM data and the BM tight-binding prediction.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
10 pages, 1 figure
Dispersive mode coupling in $p$-doped semiconductor nanomechanical resonators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Ankang Liu, Mahmoud T. Elewa, Mark I. Dykman
Dispersive coupling between vibrational modes with different frequencies is a major nonlinear dynamical effect. We show that in $ p$ -doped semiconductors such coupling is strongly enhanced. Moreover, the coupling parameters increase with the order of the nonlinearity. The doping-induced dispersive coupling becomes much stronger than the intrinsic one already for moderately strong doping. Its dependence on the hole density is nonmonotonic, and the temperature dependence becomes nonmonotonic for higher densities. Relevant mesoscopic frequency fluctuations are briefly discussed. The results are applied to Si resonators, where doping is used to compensate the temperature dependence of a clock mode, whereas another low-frequency mode is used as a thermometer to enable temperature stabilization.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
12 pages, 5 figures
Surface-switchable nonreciprocity protected by Fermi arcs in Weyl semimetal TaAs
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Dong Li, Yuki M. Itahashi, Ying-Ming Xie, Menghu Zhou, Yukako Fujishiro, Kunjie Zheng, Yao Guang, Max T. Birch, Ilya Belopolski, Max Hirschberger, Takahiro Morimoto, Xiao-Xiao Zhang, Zhi-An Ren, Naoto Nagaosa, Yoshihiro Iwasa
Weyl semimetals host topologically protected surface states, known as Fermi arcs, which connect bulk Weyl nodes in momentum space. Both bulk Weyl nodes and Fermi arcs are anticipated to be chiral. The chirality of bulk bands has been confirmed through observations of the chiral anomaly and Weyl orbits. In contrast, despite their discovery more than a decade ago, the chiral nature of Fermi arcs has remained unresolved. Here we report Fermi-arc-induced nonlinear transport in the archetypal Weyl semimetal TaAs. Using focused ion beam techniques, we fabricated micro-scale devices that enable simultaneous transport measurements on opposing topological surfaces. While linear transport remains dominated by bulk conduction, nonlinear transport uncovers surface-specific contributions, including an exceptionally large third-order nonreciprocal response that exceeds conventional expectations and highlights the crucial role of the singular arc endpoints. Our findings unambiguously demonstrate the chiral nature of Fermi arcs and establish nonlinear transport as a direct probe of these topological surface states. By revealing a surface-switchable, room-temperature nonlinear response that is topologically protected, this work introduces a new functionality in Weyl semimetals. Given the abundance of natural materials predicted to host topological semimetal states, these results open opportunities for exploring nonlinear transport phenomena and device concepts across a broad class of systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Coexistence of Donor and Acceptor Hydrogen States in n-Type InN
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Masaki Kobayashi, Yudai Yamashita, Kazuyuki Hirama, Yoshitaka Taniyasu
Hydrogen often exhibits amphoteric behavior in semiconductors, but its role is in n-type InN remains unresolved. Wurtzite InN is a narrow-gap semiconductor with high electron mobility and is therefore attractive for high-speed electronics and optoelectronic applications. Here we use hard x-ray photoemission spectroscopy (HAXPES) to probe hydrogen-related electronic structure in as-grown and post-annealed InN thin films prepared at different grown temperatures. Post annealing, which reduces the concentration of hydrogen impurities in the films, shifts the core-level spectra toward lower binding energy, consistent with a chemical-potential shift associated with the passivation of electron carriers. In the valence-band spectra, an acceptor-like in-gap feature near the valence-band maximum is suppressed after annealing. Together with the established donor-like behavior of hydrogen in InN, these results suggest that acceptor H- states coexist with donor H+ states in InN. The coexistence of these opposite hydrogen charge states provides a microscopic picture of hydrogen-driven compensation in InN and highlights the amphoteric nature of hydrogen even in a highly n-type semiconductor.
Materials Science (cond-mat.mtrl-sci)
18 pages, 9 figures
Lifetime Sample Tracking (LiST): A Data Platform for Materials Science
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Anthony Richardella, Isaiah A Moses, Konrad Hilse, Frank Santaguida, Kevin Dressler, Ric Wilburn, Saiyyam Kochar, Wesley F. Reinhart, Adri C. T. van Duin, Nitin Samarth, Vincent H. Crespi, Joan M. Redwing
The 2D Crystal Consortium Materials Innovation Platform (2DCC-MIP) is an NSF supported national user facility focused on advancing the synthesis of 2D materials, monolayers, surfaces, and interfaces. The need for the facility to organize and share data with users led to the development of an internal data management and analysis engine, the Lifetime Sample Tracking platform (LiST). This infrastructure allows the automated capture, curation, analysis and dissemination of data ranging from experimental materials synthesis parameters and characterization, to theoretical first-principles and ReaxFF molecular dynamics modeling1. The system currently hosts synthesis and property data (accessible via a REST API) on approximately twenty thousand samples produced by the 2DCC grown using a variety of techniques from bulk crystal growth to metal-organic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE), among others. Data used in publications can easily be grouped by the system into data packages that are given digital object identifiers (DOIs) for inclusion with each publication. The LiST platform is now being used by groups outside of the 2DCC as a solution for data curation in materials science. Data management tools such as LiST support the materials development process by allowing a closed loop iteration between synthesis, characterization, theory, and targeted materials design. This also enables machine learning (ML) research, artificial intelligence (AI) analysis, and the potential for autonomous synthesis in the future.
Materials Science (cond-mat.mtrl-sci)
21 pages
Vorticity Induced by Non-frontal Collisions of Quantum Droplets
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-06-17 20:00 EDT
J. E. Alba-Arroyo, Santiago F. Caballero-Benitez, Rocio Jáuregu
The rotational dynamics induced by the non-frontal binary collisions of quantum droplets composed of ultracold alkali atoms are analyzed. A theoretical study is presented within the extended Gross-Pitaevskii equation framework, using experimentally feasible conditions. Numerical experiments elucidate a rich landscape of possible topological excitations in the system that are robust towards measurements. The collision of heteronuclear quantum droplets composed of $ ^{41}$ K and $ ^{87}$ Rb atoms in the incompressible regime, gives rise to dynamical instabilities that spontaneously generate topological defects: vortex rings, dislocation lines, and vortices in one species. Their presence depends on the Weber number and the impact parameter. An experimental proposal for vortex detection in both real and Fourier space using interaction ramps is described.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
6 pages, 4 figures and 3 pages of Supplemental Material
Distinguishing Majorana zero modes from trivial defect states on the surface of the iron-based superconductor Fe(Te,Se)
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Dongfei Wang, Jon Ortuzar, Freek Massee, Ruidan Zhong, Genda Gu, Wende Xiao, Yugui Yao, Roland Wiesendanger
Majorana zero modes, which obey non-Abelian exchange statistics, are promising candidates for topological quantum computation due to their robustness against environmental perturbations. The iron-based superconductor Fe(Te,Se) has been identified as an intrinsic topological superconductor, possibly hosting Majorana zero modes. In this paper, we report the observation of near-zero-energy localized states at multiple structural defects on the Fe(Te,Se) surface, which could be misidentified as Majorana zero modes without additional verification. By using spin-polarized scanning tunneling spectroscopy, we demonstrate that the near-zero-energy localized states on step edges and line defects originate from topologically trivial Yu-Shiba-Rusinov states. In addition, zero-energy bound states are also observed for regions without surface defects. A combined spatial and magnetic field dependent analysis of the spin-resolved tunneling spectra in these regions reveals that this type of zero-energy states cannot be attributed to the presence of Majorana bound states. These findings emphasize the importance of spin-dependent studies of low-energy states for pursuing Majorana zero modes.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
19 pages, 5 figures
Hybrid Electronic-Ionic Ferroelectricity in Superlubric van der Waals Heterostructures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Jing Huang, Jun Kang, Daniel Bennett
One strategy to lower the switching barrier in a sliding ferroelectric (sFE) is to insert an incommensurate spacer to reduce sliding friction, creating a superlubric sliding ferroelectric (SL-sFE). However, how polarization survives across the effectively decoupled outer layers remains an open question. We show that SL-sFEs are fundamentally different from conventional sFEs: polarization is not driven by sliding alone, but by an intricate coupling between interlayer sliding and the out-of-plane buckling of the spacer layer. This coupling results in a unique hybrid electronic-ionic polarization arising from asymmetric orbital hybridization. The interplay of these order parameters generates several distinct types of ferroelectric hysteresis, including mixed first- and second-order transitions, multi-step switching, and antiferroelectric-like behavior, establishing SL-sFEs as a distinct class of ferroelectrics.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Hyperuniform charge distributions and phase transitions in a generalized Aubry-André model
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-06-17 20:00 EDT
Lujia Xiang, Junmo Jeon, Shiro Sakai
We show the existence of distinct inhomogeneous charge distributions and a phase transition between them in aperiodic fermion systems. Using a generalized Aubry-André model as an example, we obtain various types of charge distributions, which we classify by means of hyperuniformity, a general mean to quantify and classify the global uniformity of spatial distributions. Examining various cases of filling fraction and potential strength and shape, we find that the many-body charge distribution in this model is always hyperuniform, i.e., showing an anomalously suppressed long-range fluctuation, while its hyperuniformity class depends on the localization properties of the states around the Fermi energy, irrespective of those of high-energy states. Namely, the change in the localization properties of these single-particle states leaves a signature in the hyperuniformity class of many-body charge distribution. We further show a change of the hyperuniformity class corresponds to a phase transition between inhomogeneous many-body states, and that it is of the third order.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
12 pages, 9 figures
Flat-Band Stoner Instability and Peierls-Phase Origin of the Transdimensional Anomalous Hall Effect in Rhombohedral Graphite
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
A ``transdimensional’’ anomalous Hall effect (TDAHE), where both in-plane ($ \Bpar$ ) and out-of-plane magnetic fields produce hysteretic Hall signals, was recently observed in nine-layer rhombohedral graphite~\cite{Li2026Nature}. We present a microscopic theory attributing the TDAHE to a flat-band Stoner instability coupled to Peierls-phase gap modulation. The flat-band density of states satisfies the Stoner criterion $ U\rho(\varepsilon_F) > 1$ ~\cite{Bultinck2020}, driving a spin-valley-locked ferromagnet whose valley polarization $ \eta$ breaks time-reversal symmetry and generates an intrinsic anomalous Hall conductivity (AHC). The orbital $ g$ -factor $ g_{\mathrm{orb}} = e d_0 v_F (N{-}1)/2 \propto (N{-}1)$ then lets $ \Bpar$ modulate the gap, producing the transdimensional response $ \propto \eta$ . A self-consistent $ 2N$ -band Hartree-Fock calculation yields complete valley polarization ($ \eta \to 1$ ) below a mean-field transition $ T_c^{\mathrm{MF}} \approx 2.2$ ~K, reduced by 2D-Ising critical fluctuations to the experimental $ T_c \approx 1.6$ ~K, with $ R_{xy} \approx 1.5$ ~k$ \Omega$ . Because both Hall responses are carried by one order parameter $ \eta$ , they share a single $ T_c$ , as observed; $ T_c$ is governed by the Stoner product $ U\rho$ and is insensitive to the intervalley exchange, which only gates whether the valley-polarized phase forms, so the exchange strength is not a fitted parameter. Beyond reproducing $ R_{xy}$ , $ T_c$ , and the phase window, the theory predicts a sharp onset of valley polarization between $ N = 7$ and $ N = 9$ , a symmetry selection rule fixing the crescent Fermi surface to the $ m{=}1$ nematic channel, and a transdimensional-to-conventional Hall ratio $ \sigmaPHE/\sigmaAHE^{\mathrm{tot}} = g_{\mathrm{orb}}\Bpar/m$ independent of $ \eta$ and $ U$ . The $ Z$ -independence of the intrinsic AHC is verified within dynamical mean-field theory.
Strongly Correlated Electrons (cond-mat.str-el)
Anomalous Pairing Currents and a Second Topological Edge Channel in Bosonic Lattices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Chitrak Bhadra, Ángel Rivas, Miguel A. Martin-Delgado
We show that bosonic pairing opens a second chiral current channel on a 2D kagome lattice, absent from any particle-conserving model. From the continuity equation, we derive both a hopping current and an anomalous pairing current on the lattice, and predict chiral circulation in bulk-gapped phases with integer para-unitary Chern numbers, as well as a phase-sensitive leakage ratio, $ \Lambda_{\cal I}$ , for the pairing current around a defect. This ratio can be tuned from confined to strongly anomalous regimes at fixed topology. The two channels differ microscopically: the hopping current is sourced by the on-bond single-particle coherence, whereas the pairing current is sourced by the off-site anomalous coherence, whose spatial range is governed by the BdG pairing gap rather than by the single-particle gap. This separation produces distinct defect-induced signatures in real space, identifies a regime in which bulk topology and anomalous edge response coexist with no analogue in particle-conserving matter, and is directly testable in driven photonic lattices and superconducting-circuit arrays.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Beyond the interface: Persistent Hopping Transport and Frequency Dispersion in Strong-inversion Cryogenic MOSFETs
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Keito Yoshinaga, Wataru Miyagi, Ryo Toyoshima, Munehiro Tada, Ken Uchida
Cryogenic complementary metal-oxide-semiconductor (cryo-CMOS) technology is essential for quantum computing interfaces, which require precise modeling of dynamic device behavior. The output impedance of MOS field-effect transistors (MOSFETs) is frequency dependent, which has been conventionally attributed to extrinsic parasitics. Here, we report an intrinsic frequency dispersion in the channel impedance of cryogenic MOSFETs that persists deep into the strong-inversion region. Through a Cole-Cole analysis, we characterize this dispersion as a depressed semicircle in the impedance plane and attribute its behavior to variable-range hopping through band-tail localized states. Unlike conventional models where band-tail states are confined to the oxide interface, we demonstrate that in MOSFETs with high channel doping the band-tail states are induced by ionized impurities and distributed throughout the depletion region. Our paradigm accounts for frequency dispersion under strong inversion. This work demonstrates that ionized-impurities-induced hopping governs the dynamic response of cryo-MOSFETs channel impedance even when drift conduction dominates, offering critical insights for accurate small-signal modeling and high-frequency cryo-CMOS circuit design.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Brownian gyration of an inertial ellipsoid
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
Recent studies on Brownian gyration (BG) have focused primarily on spherically symmetric particles under overdamped conditions. To explore BG in the underdamped regime with a spherically asymmetric particle, we investigate the inertial dynamics of a microscopic ellipsoid in a dissipative medium. The particle is confined in a spherically asymmetric trap and simultaneously coupled to two distinct thermal reservoirs. This configuration drives the system into a nonequilibrium steady state (NESS) characterised by BG, which is quantified by the mean and fluctuation of the particle’s specific angular momentum. Using inertial Langevin dynamics, we systematically analyze how this microscopic gyration depends not merely on the trap asymmetry and temperature difference, but also on the particle’s intrinsic physical properties like shape and axial orientation, besides inertia. Our study uncovers fundamental differences between the gyration of spherical and non-spherical particles in overdamped as well as underdamped conditions, at microscopic scales. These findings provide key insights for optimizing Brownian gyration across a broader landscape of experimentally tuneable parameters.
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
20 pages, 15 figures
Defect Localization by Stress Anisotropy in Active Nematic Turbulence
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-06-17 20:00 EDT
Collective stress generation in cellular monolayers is a key phenomenological process governing coordinated migration and emergent multicellular dynamics. We employ a generic active nematics model to investigate stress generation and its associated properties. By analyzing the maximal principal stress and its correlation with the nematic director across different activity strengths, we find that the principal stress aligns perpendicular (parallel) to the nematic director for extensile (contractile) activity. In the turbulent regime, we identify a distinct isoline derived from anisotropic stress components along which all $ \pm 1/2$ defects (both nematic and stress) are localized. This feature is robust and remains unchanged with variations in both the magnitude and nature (extensile or contractile) of activity. Our findings provide a new route to probe the mechanical and rheological properties of confluent cell layers, where stress measurements are more accessible than detailed cell shape or size characterization.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
8 pages, 8 figures
Atomic-scale sensing of photoexcitation processes in electronically isolated molecules via atomic force microscopy
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Lisanne Sellies, Thomas Buchner, Jinhui Guo, Sonja Bleher, Felix Giselbrecht, Clea Ruth, Andrea Donarini, Jascha Repp, Laerte L. Patera
Atomic-scale insights into light-matter interaction can be obtained using light-assisted scanning probe microscopy techniques. Recently, photoexcited charge carriers have been detected by means of scanning tunnelling microscopy, enabling the study of photo-induced charge transfer with atomic-scale spatial resolution. Here, we propose an approach based on atomic force microscopy (AFM), namely photoexcitation single-charge AFM (PE-AFM), to detect photoexcitation in single molecules adsorbed on non-conductive dielectric films. Synchronizing laser pulses to the oscillation of the tip of an AFM enables the detection of electron tunnelling events that follow photoexcitation. We demonstrate the PE-AFM technique for individual copper phthalocyanine molecules and achieve photoexcitation-driven AFM contrast with ångström spatial resolution. The observed sub-molecular contrast suggests the involvement of a long-lived quadruplet excited state. When combined with the recently developed AFM excited-state spectroscopy including lifetime measurements, PE-AFM enables comprehensive characterization of electronic states involved in photoexcitation and subsequent intersystem crossing, establishing a powerful platform for investigating photophysical processes at the single-molecule level.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
31 pages, 5 figures
Work Extraction via Backward Motion in Optimal Closed-Loop Stochastic Control
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
Luis Frieder Reinalter, Emanuele Panizon, Lokesh Muruga, Clemens Bechinger
We experimentally realize finite-time feedback control in an overdamped colloidal system using real-time optical tweezers with in situ reinforcement learning (RL). By varying the protocol duration tf for displacing the optical trap between prescribed positions, the optimal strategies identified by RL reveal a crossover from deterministic dragging toward the target to feedback-assisted exploitation of thermal fluctuations, reducing and eventually overcoming the energetic cost. The resulting policies agree quantitatively with the exact optimal closed-loop solution. By extending the approach to spatially localized external forcing, we further show that RL can identify optimal feedback strategies in heterogeneous stochastic environments where direct analytical control design is challenging.
Statistical Mechanics (cond-mat.stat-mech)
Ground-state properties of the $S=3/2$ anisotropic triangular lattice antiferromagnet Na$_3$Cr(PO$_4$)$_2$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
A. Magar, Sebin J. Sebastian, Q.-P. Ding, Y. Skourski, A. A. Tsirlin, Y. Furukawa, R. Nath
We report the crystal structure and magnetic properties of a $ S=3/2$ anisotropic triangular lattice compound Na$ 3$ Cr(PO$ 4$ )$ 2$ employing single-crystal and powder x-ray diffraction, magnetization, heat capacity, and $ ^{31}$ P nuclear magnetic resonance (NMR) experiments, supported by the band structure calculations. Magnetic susceptibility exhibits a broad maximum around 3.5 K, indicating the presence of a short-range antiferromagnetic order, typical of a low-dimensional spin system. Magnetization and heat capacity manifest an antiferromagnetic long-range ordering at around $ T{\rm N} \simeq 2.6$ K. This was further confirmed by the drastic NMR line broadening and a peak in the nuclear spin-lattice and spin-spin relaxation rates. The isothermal magnetization data exhibit a field-induced spin-flop transition at around $ \mu_0H{\rm SF} \simeq 1.7$ T reminiscent of an anisotropic two-dimensional magnet, before saturating above $ \mu_0H{\rm sat} \simeq 4.5$ T. The saturation field was further upheld by the field-dependent NMR relaxation measurements at low temperatures. The $ ^{31}$ P NMR spectral shape confirms the commensurate antiferromagnetic nature of the ordering below $ T_{\rm N}$ . \textit{Ab initio} calculations reveal a significant deformation of the triangular spin lattice, resulting in triangles with two antiferromagnetic couplings of similar strength and a much weaker coupling along the third side of the triangle.
Materials Science (cond-mat.mtrl-sci)
14 pages, 13 figures
Probing La-based nickelates with Ni 1$s$ core-level photoelectron spectroscopy
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
Daisuke Takegami, Naoki Ito, Koto Fujinuma, Masato Yoshimura, Grace A. Pan, Dan Ferenc Segedin, Qi Song, Hanjong Paik, Charles M. Brooks, Hanjie Guo, Alexander C. Komarek, Takanori Taniguchi, Masaki Fujita, Julia A. Mundy, Takashi Mizokawa, Liu Hao Tjeng, Berit H. Goodge, Atsushi Hariki
We present a comparative Ni core level photoemission study of La$ _3$ Ni$ _2$ O$ _7$ , Nd$ _3$ Ni$ _2$ O$ _7$ , and LaNiO$ _3$ using both the Ni $ 2p$ and the Ni $ 1s$ . We address the challenges in analyzing the widely investigated Ni $ 2p$ spectra arising from the substantial overlap in energy of the Ni $ 2p$ with the La $ 3d$ . We show that on the other hand the deep Ni $ 1s$ core level does provide a clean view on the intrinsic electronic excitations and we highlight its potential to resolve detailed differences in the electronic structure within the strongly correlated Ruddlesden-Popper series La$ _{n+1}$ Ni$ _n$ O$ _{3n+1}$ .
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Graphene Josephson diodes from inherent asymmetric disorder
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Ivan Villani, Luca Chirolli, Matteo Carrega, Alessandro Crippa, Elia Strambini, Francesco Giazotto, Vaidotas Miseikis, Camilla Coletti, Fabio Beltram, Kenji Watanabe, Takashi Taniguchi, Stefan Heun, Sergio Pezzini
Josephson diodes are non-reciprocal superconducting devices characterized by different switching currents depending on the current flow direction. They recently attracted considerable theoretical and experimental attention, in view of their possible application as rectifying elements in the field of superconducting electronics, and as probes to investigate symmetry breaking mechanisms in mesoscopic systems. In this work, we show that graphene Josephson junctions provide rectification of supercurrent with an efficiency exceeding 20%. The effect appears applying a mT out-of-plane magnetic field and is enhanced close to the nodes of the Fraunhofer interference pattern. Our theoretical model identifies long-range scattering potentials in the junction as the symmetry-breaking mechanism, which yields supercurrent rectification in highly transparent junctions. While graphene stands as an ultra-clean transmission medium, our work shows that unavoidable residual disorder in a clean two-dimensional system is sufficient to promote this effect. Tailoring of the inversion (mirror) symmetry breaking could be obtained via proper design of external gates.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
25 pages, 10 figures
Surface Induced Magnetism of CdSe Quantum Dots: A DFT Study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
G. Kurian, D. Subedi, A. Aniagboso, M. D. Mochena
Surface induced magnetism of quantum dots is not well understood and has been a subject of considerable controversy because of the complexity of surface chemistry of quantum dot facets coupled with the many degrees of freedom inherently involved in magnetism. We performed spin-polarized colinear density functional theory calculations to study charge and spin densities to determine surface reconstructions in bare as well as passivated quantum dots in controlled way. We find that tricoordinated surface atoms relax contributing no dangling bonds and bi-coordinated atoms dimerize, reducing the population of the dangling bonds affecting the induced magnetism. As a result, bicoordinated rather than tricoordinated surface atoms are responsible for spin polarized surface states. In light of recent advanced experimental tools, we predict dangling bonds that remain, despite passivation, on low index facets with bicoordinated atoms could result in tunable surface magnetism. Our results also shed light on the contradicting experimental results in the literature.
Materials Science (cond-mat.mtrl-sci)
17 pages, 9 figures, 2 tables
First-order phase transitions in the three-dimensional Blume-Capel ferromagnet
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
D. Mataragkas, A. Vasilopoulos, Z.D. Vatansever, Y. Kim, D.-H. Kim, N.G Fytas
We investigate first-order phase transitions in the three-dimensional Blume-Capel ferromagnet on the simple cubic lattice by combining multicanonical simulations with two-parameter Wang-Landau sampling. The generalized-ensemble approach enables a detailed characterization of the coexistence region over a broad range of temperatures and crystal-field couplings, extending from the vicinity of the tricritical point deep into the first-order regime. We analyze the finite-size scaling behavior of thermodynamic observables, with particular emphasis on the energy probability density function, free-energy barriers, and interfacial properties. The evolution of the double-peaked energy distributions reveals a gradual crossover from weak to strong first-order behavior as the temperature is lowered. From the scaling of the free-energy barrier we determine the interface tension along the coexistence line and characterize its approach to the tricritical region through its vanishing behavior. In parallel, a field-mixing analysis based on the joint density of states obtained from two-parameter Wang-Landau simulations is employed to locate first-order transition points and probe tricritical behavior. While this approach has been highly successful in two-dimensional realizations of the Blume-Capel model, we find that in three dimensions its practical implementation becomes increasingly sensitive in the vicinity of the tricritical region, where the shallow structure of the relevant scaling variable distribution limits the ability to resolve coexistence conditions for the system sizes currently accessible. These results delineate the range of applicability of the method in three dimensions and provide a consistent picture of the first-order regime of the model.
Statistical Mechanics (cond-mat.stat-mech)
12 pages, 6 figures, 1 table, submitted to Physica A
Using fast-reactive crosslinkers to modulate the internal structure of thermoresponsive microgels
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-06-17 20:00 EDT
Ballin Elisa, Brasili Francesco, Sztucki Michael, Rovigatti Lorenzo, Sennato Simona, Zaccarelli Emanuela
The internal architecture of poly(N-isopropylacrylamide) (PNIPAM) microgels, which switches from fuzzy-sphere to star-like when the standard N,N’-methylenebis(acrylamide) (BIS) crosslinker is replaced with ethylene glycol dimethacrylate (EGDMA), critically determines their interactions and swelling behavior. Here, we systematically investigate the role of the surfactant and crosslinker content in modulating the internal structure of the microgels using Dynamic Light Scattering, Small-angle X-ray Scattering and monomer-resolved numerical simulations. We reveal that the presence of the surfactant is crucial for obtaining the star-like architecture, and that the transition from the star-like regime to a more core-dominated structure occurs above a threshold EGDMA concentration. Monomer-resolved simulations capture how the role of surfactant differs between EGDMA-crosslinked and BIS-crosslinked microgels. Our findings establish a direct synthesis-structure relationship, providing a clear guidance for the rational design of soft, star-like microgels with ultra-soft interactions, strenghtening the connection between microgels and model star polymers.
Soft Condensed Matter (cond-mat.soft)
AC-flux-driven SQUID diode spectroscopy as a probe of current-phase relations
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Yuriy Yerin, Iman Askerzade, Alexey Fedorchenko, Ali Gencer, Oleksandr Dobrovolskiy
The current-phase relation (CPR) of a Josephson junction encodes microscopic information on superconducting states through higher-order and fractional harmonics. However, their unambiguous extraction is challenging, as different CPR components produce nearly identical static interference patterns that are further obscured by device asymmetries, damping, and dynamical effects. Here, we propose probing individual CPR harmonics via the ac magnetic-flux-driven diode effect in asymmetric dc SQUIDs with unequal junction critical currents. Using two complementary reductions of the fast-driven dynamics – a Kapitza-type perturbation theory for the conventional junction and a Jacobi–Anger averaging for a general CPR – we show that ac flux modulation dresses each harmonic with a distinct Bessel function, yielding characteristic signatures in the diode efficiency $ \eta(\phi_{\rm ac},\omega)$ as a function of ac flux amplitude $ \phi_{\rm ac}$ and frequency $ \omega$ . We verify and extend these predictions by numerical solutions of the coupled dynamical equations for CPRs containing $ \sin\varphi$ , $ \sin(\varphi/2)$ , and $ \sin 2\varphi$ terms ($ \varphi$ : superconducting phase difference), and construct phase diagrams of $ \eta(\phi_{\rm ac},\omega)$ . Distinct CPR components are revealed to produce characteristic weak, sparse, dense, or intermodulated arc patterns that remain robust in both overdamped and underdamped regimes. This suggests ac-flux-driven SQUID diode spectroscopy as a probe of current-phase relations in topological materials, multiband systems, and other unconventional superconductors.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
14 pages and 9 pages of the Supplemental Material, 7 figures, comments are welcome
AC calorimetric study of magneto-quantum oscillations in anisotropic multiband V$_2$Ga$_5$ superconductor
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Yevhen V. Petrenko, Jozef Kačmarčík, Tomáš Samuely, Jozef Haniš, Slavomír Gabáni, Szymon Królak, Michal J. Winiarski, Tomasz Klimczuk, Martin Gmitra, Peter Samuely
Unlike de Haas–van Alphen measurements, heat-capacity magneto-quantum oscillations directly probe the oscillatory bulk quasiparticle density of states. Here, we report the observation of MQOs in V$ _2$ Ga$ _5$ single crystals studied via highly sensitive ac calorimetry. The strongest MQO signal is observed for a magnetic field applied along the vanadium chains, in excellent agreement with de Haas–van Alphen magnetization data. A single dominant frequency of 126.6 T resolved by fast Fourier transform confirms the true bulk origin of the elliptical $ \gamma$ Fermi-surface pocket located near the Z point of the Brillouin zone. The angular dependence of the FFT frequency closely tracks the anisotropy of the $ \gamma$ pocket, as supported by first-principles calculations. Analysis of the temperature- and field-dependent MQO amplitudes allows the precise determination of the effective cyclotron mass, Dingle temperature, quantum relaxation time, carrier mobility, and electron mean free path. Furthermore, we demonstrate that the net Berry flux is invariant with respect to the magnetic-field orientation, as a consequence of a conserved hybridization phase twist within the $ \gamma$ pocket. These findings establish ac calorimetry as a powerful macroscopic probe of topological orbital hybridization in complex intermetallics.
Superconductivity (cond-mat.supr-con)
15 pages, 10 figures
Effect of inter-edge interaction in a quantum Hall collider
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Amulya Ratnakar, Flavio Ronetti, Benoît Grémaud, Laurent Raymond, Thierry Martin, Thibaut Jonckheere, Jérôme Rech
Fractional quantum Hall (FQH) colliders measure anyon exchange phases via time-domain braiding, but the $ \nu=2/5$ state exhibits an intriguing negative Fano factor, challenging theoretical predictions. Here, we study the effect of inter-edge interactions in a multi-mode FQH collider. We demonstrate that the resulting fractionalization into eigenmodes causes the anyon beam to decompose into correlated and uncorrelated components, which have very distinct behavior in terms of time-domain braiding. We show that the uncorrelated part dominates in the long-junction limit, reversing the tunneling current sign and reproducing the observed negative Fano factor at $ \nu=2/5$ . Our results highlight the role of interactions and provide a robust interpretation of anyonic braiding in multi-mode systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 Pages, 4 figures, Supplementary Material added
Electronic access to glass transition in supercooled ionic liquids using ambipolar transistor
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-06-17 20:00 EDT
Tanima Kundu, Rahul Paramanik, Aishee Saha, Shibnath Mandal, Antarik Sarkar, Bipul Karmakar, Subhadeep Datta
Relaxation dynamics of supercooled liquids approaching glassy arrest remain a central challenge in integrated electronic architectures, where conventional rheometry becomes incompatible. Here, we demonstrate that an ambipolar PdSe$ 2$ field-effect transistor functions as an electrical probe capable of resolving ion-specific relaxation dynamics in fragile ionic glass formers and semiquantitatively inferring rheological parameters within an operating device environment. Temperature evolution of the transfer curve hysteresis and time-resolved current transients under ionic-gate pulse reveal a non-Arrhenius fragile slowdown. We track the continuous reduction of dynamically equilibrated liquid regions approaching the glass transition through an electrically accessible quantity $ p\text{eq}(T)$ , quantifying the fraction of the mobile ions able to relax within the experimental timescale. Upon cooling, $ p_\text{eq}$ collapses sharply as mobile regions fragment into percolating fractal clusters, consistent with a reduction of configurational entropy predicted for fragile glass formers. This approach enables temperature-dependent scaling of viscosity and extraction of characteristic temperatures marking the ergodic-to-nonergodic crossover, within a solid-state device architecture where conventional rheological characterization is inapplicable. Further, polymer confinement of the ionic liquid shifts these characteristic temperatures upward, demonstrating the sensitivity of this method to structural constraints imposed by the polymer matrix.
Soft Condensed Matter (cond-mat.soft)
accepted in Physical Review E
Spin-Wave Phase Shifter Controlled by a Domain Wall Racetrack
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Uladzislau Makartsou, Olena Tartakivska, Paweł Gruszecki, Anton Lutsenko, Sebastiaan van Dijken, Volodymyr V. Kruglyak, Maciej Krawczyk
We propose a spin-wave phase shifter controlled using a domain-wall racetrack. The concept is demonstrated using micromagnetic simulations of a Permalloy domain-wall racetrack placed above a YIG film. The stray field from pinned domain walls modifies the internal magnetic field in the YIG region under the racetrack. This leads to a local change of the spin-wave wavelength and thereby enables control of the phase accumulated by Damon-Eshbach spin waves propagating through the region. Moving domain walls on the racetrack, the same physical structure can provide phase shifts of up to +/-90 degrees, without changing the waveguide geometry. A model based on the semiclassical approximation confirms that the phase shift is dominated by the domain-wall-induced stray field. These results suggest a route toward a compact programmable spin-wave phase shifter for interference-based magnonic circuits for information processing. Moreover, the demonstrated magnonic device integration with a magnetic domain-wall racetrack can lead to its application in in-memory computing.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
15 pages, 9 figures (6 in the main text, 3 in the supplementary material). Supplementary material included
Tunneling amplifies chirality-induced spin selectivity and explains its current-direction invariance
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Fedor Baranov, Virginia Gali, Gal Lemut, Maxim Breitkreiz
We propose a minimal model for chirality-induced spin selectivity (CISS) in dc transport through insulating chiral molecules, based on quantum tunneling and interaction-induced spin splitting. As a concrete realization of the latter, we consider a weak Zeeman interaction of the particle spin with the current-induced magnetic field, recently shown to occur in helical molecules. We show that quantum tunneling, combined with dissipation, amplifies the effect, so that even such a small spin-dependent perturbation can yield spin polarizations on the order of 100% across a wide range of applied bias voltages. Furthermore, our tunneling scenario naturally reproduces the characteristic CISS symmetry of the current-voltage dependence – namely, the invariance of the spin-polarization sign under reversal of the current direction – while fully respecting Onsager’s reciprocity relations.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
8 pages, 5 figures
Bridging the continuum and the kinetic-Boltzmann theories of heat flow through generalized Knudsen numbers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Nikhil Malviya, Navaneetha K. Ravichandran
Heat conduction in semiconductor crystals is fundamentally governed by the linearized Peierls-Boltzmann equation (LPBE) for phonon transport, that arises out of a kinetic theory for phonon quasiparticles. Yet, continuum theories such as the Fourier’s heat diffusion, weakly quasiballistic and hydrodynamic heat equations are often used to explain the experimental observations of heat flow in these materials. Here, we show that a systematic reduction of the LPBE into such equivalent continuum descriptions are possible only for the limiting values of a set of generalized Knudsen numbers. We further show that all of these continuum heat flow regimes, along with the ballistic heat flow, can be described by a single continuum equation for the temperature field that originates from the eigenmode analysis of the LPBE, thus offering a unified picture of all possible heat flow regimes in semiconducting crystals. Using quantitative examples on twenty three technologically important semiconductors, we show that several previously-unidentified features of the non-Fourier heat flow regimes emerge from this generalized Knudsen number framework such as (1) the mutual exclusivity of the weakly quasiballistic and the hydrodynamic heat flow regimes, (2) length-dependent velocity of the hydrodynamic second sound temperature wave and a characteristic heating length for the strongest hydrodynamic second sound, (3) characteristic frequency-domain temperature response distinguishing the hydrodynamic second sound from the ballistic heat flow regime and, (4) a new non-oscillatory signature of transient hydrodynamic heat flow. Our work formally bridges the continuum and the particulate descriptions of heat flow, and provides insights into the important signatures of temperature dynamics in each of these heat flow regimes, that will aid in their unambiguous experimental observations in the future.
Materials Science (cond-mat.mtrl-sci), Mathematical Physics (math-ph)
The antiferromagnetic transition in the frustrated bixbyite $β$-Fe$_2$O$_3$ magnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
Chenjun Tang (1), Ondřej Malina (2 and 3), Jiři Tuček (4), Francois Fauth (5), Marti Gich (1), Jose Luis Garcia-Muñoz (1) ((1) Institut de Ciència de Materials de Barcelona (ICMAB-CSIC). Cerdanyola del Vallès. Spain., (2) Regional Centre of Advanced Technologies and Materials. CATRIN. Olomouc. Czech Republic., (3) Nanotechnology Centre-CEET VSB-TUO. Ostrava. Poruba, Czech Republic., (4) Research Centre of FEEI-UPCE. Pardubice. Czech Republic., (5) CELLS-ALBA Synchrotron. Cerdanyola del Vallès (Barcelona). Spain)
Although Fe$ _2$ O$ _3$ compounds are among the most extensively studied transition-metal oxides, the magnetic properties of $ \beta$ -Fe$ _2$ O$ _3$ remain poorly characterized. Using neutron and synchrotron X-ray diffraction, we investigate the temperature-driven magnetic transition in $ \beta$ -Fe$ _2$ O$ 3$ . A noncollinear antiferromagnetic structure sets in abruptly via activation of irrep $ mH_1^{+}$ at the H-point [$ \mathbf{k}=(1,1,1)$ ] together with antitranslation $ (1’|\tfrac{1}{2},\tfrac{1}{2},\tfrac{1}{2})$ . Below $ T{\mathrm{N}}$ , the magnetic cell becomes primitive $ (P_I a \bar{3})$ , yielding two interpenetrating primitive cubic subcells with inverted moments and non-polar type-IV symmetry. All Fe$ ^{3+}$ -O-Fe$ ^{3+}$ exchanges are antiferromagnetic, and the bixbyite structure promotes geometric frustration and noncollinear magnetism through coexisting magnetic sublattices with distinct symmetries and easy axes. Its frustration index $ f \simeq 7.6$ is among the highest reported for binary magnetic oxides. In $ {111}$ planes, distorted Fe2O$ _6$ octahedra form hexagonal rings interconnected by triangular units. Notably, hexagonal Fe2 rings host a central Fe1 ion with strong Ising-like anisotropy, which could act as a switching element for the rings’ magnetic state. These features point to routes for functional design.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
30 pages, 14 figures, 6 Tables
Nonlinear Optical Probing of Ferroic-Octupolar Order Parameter in Collinear Altermagnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
P. A. Usachev, R. V. Pisarev, V. V. Pavlov
Altermagnetism as a new concept in condensed matter physics is currently being thoroughly investigated. Despite the absence of macroscopic magnetization, altermagnets host a hidden spin order whose direct detection remains a challenge. Here we report on the observation of electric and magnetic dipole forbidden optical second-harmonic generation (SHG) in the altermagnet CoF$ _2$ with a centrosymmetric lattice and spin order. We demonstrate that below the Néel temperature $ T_N = 38$ K the SHG signal is sensitive to the ferrotype magnetic octupole $ \mathbf{\mathcal{O}}^M$ which is the order parameter in the antiferromagnetic phase. By combining polarization-resolved SHG experimental data and a phenomenological symmetry analysis, we show that the altermagnetic spin structure of CoF$ 2$ enables a ferroic-octupole-induced electric-quadrupolar nonlinear polarization $ \mathbf{P}^{2\omega} = \mathrm i\varepsilon{0}{ }^c\mathbf{\chi}^{(3)}(\mathbf{\mathcal{O}}^M) :\mathbf{E}^{\omega} \nabla \mathbf{E}^{\omega}$ . The temperature dependence of SHG reveals a phase transition at $ T_N$ confirming the spin origin of the observed signal. The SHG response is resonantly enhanced by a coherent three-photon process caused by the electronic $ d$ -$ d$ transitions of the Co$ ^{2+}$ ion. Model calculations of SHG polarization rotational anisotropies and temperature dependencies give a reasonable agreement with experimental data, proving the disclosed nonlinear contribution. Our results establish SHG as a novel sensitive tool of ferroic-octupolar spin ordering and highlight the potential of CoF$ _2$ and other altermagnets for further nonlinear optical investigations and applications.
Strongly Correlated Electrons (cond-mat.str-el)
Higher-order topological metasurface based on split-ring resonators with dipole-quadrupole couplings
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Alina D. Rozenblit, Nikita A. Olekhno
Photonic higher-order topological insulators (HOTI) are characterized by a hierarchy of topologically-protected states with different dimensionalities, making them especially interesting for potential applications that combine strong localization of electromagnetic fields and their robust waveguiding. However, their practical implementation often requires expensive processing techniques and is limited by accessible material parameters. In this paper, we demonstrate that a radio-frequency photonic HOTI can be implemented as a metasurface composed of split-ring resonators with couplings between dipole and quadrupole modes. We verify, by numerical simulations and experimentally at frequencies of 1.5-1.7 GHz, that a proposed metasurface supports corner- and edge-localized states. Our results reveal a scalable and easily reconfigurable GHz-range platform that employs printed circuit board technology, thus making crucial steps required for further experimental studies of photonic HOTI and the development of their microwave applications.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph), Optics (physics.optics)
7 pages, 5 figures + Supplementary Materials
Chirality-induced spin selectivity without intrinsic spin-orbit coupling: Role of current-induced molecular orbital moment
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Sumit Ghosh, Angela Wittmann, Frank Matthes, Daniel E. Bürgler
The microscopic origin of the chirality-induced spin selectivity (CISS) in helical molecules remains an open question. Recent experiments suggest that a significant contribution to CISS arises from the molecule itself, which is disregarded in existing interfacial or scattering based theories. Here we present an alternative theory of CISS to address this molecular contribution. The mechanism is based on the circulation of charge current in molecular loops that generates a molecular orbital moment (MOM). The direction of the MOM is governed by the gauge field arising from the structural distortion of the molecule and is associated with the handedness of the molecule. Such a MOM can produce finite CISS magnetoresistance and magnetochiral conductance asymmetries that are even in bias voltage, without violating the Onsager-Casimir reciprocity relations. Depending on the Fermi level and bias voltage, the MOM can be controlled externally, which can result in additional crossings of the enantiomer $ I-V$ curves. Finally we explain the origin of the electrical magnetochiral anisotropy within the same framework, which establishes its generic applicability.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 7 figures, 3 appendices
Replica theory for the rate functional of the empirical spectral distribution function of diluted Hermitian matrices
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-06-17 20:00 EDT
Edgar Guzmán-González, Isaac Pérez Castillo
We develop a replica-based framework for the scaled cumulant-generating functional of the empirical spectral distribution function $ i_C$ of diluted Hermitian random matrices. Within a replica-symmetric saddle-point assumption, this construction yields a candidate rate functional for fluctuations of $ i_C$ . As an illustrative application, we consider adjacency matrices of unweighted Erdős-Rényi random graphs with mean degree $ c$ . We derive explicit expressions for the first two cumulants of $ i_C$ , indicate how higher cumulants can be obtained from further functional derivatives, and compute the rate function of Fourier coefficients, equivalently of selected linear spectral statistics. The replica-symmetric predictions are tested against exact numerical diagonalization and show good agreement in the accessible fluctuation regime. The approach provides a basis for studying rate functionals of spectral observables in sparse random matrix ensembles.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
7 pages + 5 pages supplemental material, 3 figures
Robust Signatures of Fragile Topology
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Viktor Könye, Ihor Nimyi, Oleg Janson, Jeroen van den Brink, Jasper van Wezel, Cosma Fulga
Some topological phases of matter are called fragile. They do not generically host protected gapless boundary states and they can be trivialized by adding additional valence bands. Here we show that fragile topology nevertheless has robust signatures: it yields bulk Dirac cones in two-dimensional materials with arbitrarily many bands. In systems with time-reversal and twofold rotation symmetry, we establish a fragile topological index which guarantees the presence of gap closing points in the band structure. We test this prediction using first-principles calculations in five materials and find that all of them host such Dirac points, suggesting that this is a widespread phenomenon. Our results provide a robust spectroscopic signature of fragile topology which can be directly accessed in experiment. Further, they enable an alternate method for finding Dirac cones in ab-initio simulations, and may be used as a route towards identifying materials with nonlinear transport properties.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Finite and disordered Kitaev chains: a large deviation study
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-06-17 20:00 EDT
Clément Fortin, Kai Wang, Tami Pereg-Barnea
Topological edge states are celebrated for their robustness against disorder, yet the interplay between disorder and system size remains poorly understood. We use large deviations theory as a framework to study finite-size effects beyond the central limit theorem. We analyze Lyapunov exponent fluctuations in the static and periodically driven disordered Kitaev chain and find an asymmetry in the large deviations statistics that makes stronger edge localizations of Majorana zero modes exponentially more likely than weaker ones. We demonstrate that this fluctuation asymmetry is not tied to the topological phase. This asymmetry endows topological edge states with an additional protection against disorder and persists across a broad class of disorder distribution. We show how to use our framework to find the minimum system size required to satisfy topological quantum computing constraints.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
8 pages, 3 figures
Influence of Ultramicroporosity and Surface Chemistry on Dynamic CO2 Capture in Activated Carbons
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
S. Gooijer, P. Goosen, C. G. Díaz-Maroto, I. Moreno, S. Calero, J. Fermoso, J. M. Vicent-Luna
Activated carbons are promising adsorbents for post-combustion CO2 capture due to their high surface area, tunable microporosity, and resistance to moisture and flue-gas impurities. Despite extensive equilibrium adsorption studies, the dynamic behavior of activated carbons under fixed-bed operating conditions relevant to post-combustion CO2/N2 remains insufficiently understood, particularly for renewable materials. In this work, the adsorption and separation behavior of CO2/N2 mixtures on a commercial coal-derived activated carbon (WS-480) and a biomass-based activated carbon (MSP700-A900CO2) is comparatively evaluated by combining experimental measurements and simulations. We examine the physicochemical properties of both materials, revealing that although WS-480 exhibits a higher of porosity, MSP700-A900CO2 contains a larger fraction of ultramicropores (<0.7 nm) and a broader distribution of oxygen-containing functional groups. These characteristics result in higher CO2 adsorption capacities for MSP700-A900CO2 in fixed-bed breakthrough experiments conducted under varying flow rates, temperatures and CO2 concentrations. We employ atomistic activated carbon models, augmented with surface functional groups as representations of WS-480 and MSP700-A900CO2, achieving close agreement with experimental adsorption data. The validated models are subsequently used to predict CO2/N2 separation under equilibrium and dynamic conditions, reproducing the experimental breakthrough behavior while providing molecular-level insight into the influence of pore structure and surface chemistry on adsorption performance.
Materials Science (cond-mat.mtrl-sci)
Hydrogen s-electrons as the origin of crystal magnetism beyond spin-orbit coupling
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Baiqiang Liu, Zhen Gong, Rui Liu, Siyang Liu, Yue Feng, Zhigang Wang
Magnetism has long been attributed to localized d, f, and even p electrons with strong correlations, whereas s electrons exemplified by hydrogen are reactive and tend to have their spins quenched, making s-electron-derived magnetism and long-range ordered magnetic crystals seem unattainable. Here we report a low-Z ferromagnetic crystal H13@(BN)12 using first-principles calculations, where thirteen hydrogen atoms are encapsulated within a (BN)12 cage and magnetism originates from the 1s electron of the central hydrogen atom. The crystal remains stable under ambient pressure owing to chemical precompression. Notably, the central hydrogen atom retains a magnetic moment of 1 {\mu}B, with long-range magnetic order established through multicenter bonding within the H13 aggregate and the intercell B-B network, while the zero orbital angular momentum of s electrons renders spin-orbit coupling (SOC) negligible as expected. Electronic structure analyses reveal that the large cavity and central negative electrostatic potential of the (BN)12 cage localize the hydrogen 1s electron, preventing spin quenching. Interestingly, under 16 GPa compression, the system transforms into a nonmagnetic metallic state driven by delocalized electrons of the central hydrogen atom. This study opens a pathway for constructing s-electron-driven magnetic materials and lays the foundation for developing low-energy consumption magnetic devices without SOC.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Atomic Physics (physics.atom-ph), Chemical Physics (physics.chem-ph), Computational Physics (physics.comp-ph)
19 pages, 3 figures
Three-dimensional repulsive Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
The three-dimensional repulsive Hubbard model is investigated using the strong-coupling diagram technique. For half-filling, the boundary between paramagnetic and antiferromagnetic states is determined for the range of the Hubbard repulsion $ 4t\leq U\leq12t$ , where $ t$ is the hopping integral between neighboring sites. Along this boundary, the density of states is calculated, and it demonstrates the Mott transition at $ U\approx9t$ . For $ U\geq6t$ and half-filling, the density of states has the shape inherent in the strong electron repulsion, while for $ U=4t$ , its shape points to weak coupling. The dependence of the Néel temperature $ T_{\rm N}$ on the electron concentration $ \bar{n}$ is investigated for the cases $ U=4t$ and $ 12t$ . In the former case, $ T_{\rm N}$ decreases monotonously with $ \bar{n}$ , while in the latter case, there is a plateau in the dependence near $ \bar{n}=0.87$ . The plateau is connected to a reconstruction of the density of states caused by an effective weakening of electron coupling due to electron depopulation. For $ U=12t$ and half-filling, the magnetic critical exponent $ \gamma\approx1.4$ , which is close to the value in the Heisenberg model. Some features resembling the first-order phase transition, revealing themselves in a finite crystal, are discussed.
Strongly Correlated Electrons (cond-mat.str-el)
17 pages, 9 figures
Torsion-controlled spin transport and tunable intersubband absorption in a screw-dislocated semiconductor nanowire
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Carlos Magno O. Pereira, Edilberto O. Silva
We develop an effective-mass theory for spin-resolved transport and intersubband optical absorption in a finite semiconductor nanowire containing a uniform screw-dislocation-induced torsion. The central transport quantity is the band bottom of each torsion-dependent one-dimensional subband: torsion lowers this band bottom while an axial magnetic field resolves the two Zeeman branches, so that a spin-selective torsion interval opens when the Fermi level lies between the two branch minima. We distinguish this band-bottom transport threshold from the fixed-momentum transverse energy that governs the vertical intersubband optical transition, and obtain a design rule for the width of the spin-selective torsion interval that is linear in the Zeeman splitting in the small-splitting limit. Finite-size effects are incorporated by treating the active region as an open scattering region of length $ L$ and radius $ R$ , with Fabry-Perot interference, radial boundary conditions, and surface-induced linewidth broadening. The spin-resolved response remains well defined when the effective linewidth satisfies $ \Gamma_{\mathrm{eff}}\ll\Delta_Z$ , a criterion quantified through polarization and conductance-contrast maps. In the optical sector, finite-radius intersubband absorption gives a torsion-tunable resonance in the THz range; surface boundary conditions shift the absolute resonance frequency and modify the oscillator strength, while, for the dominant unit-branch transition, the leading fixed-momentum torsional slope $ \partial\omega/\partial\tau\simeq\hbar k_F/m^\ast$ is preserved. The resulting framework connects geometric torsion, spin-resolved mesoscopic transport, spin thermopower, and tunable intersubband absorption within a single open-quantum-wire model.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 8 figures, 1 table. Comments are welcome
Revisiting quantum effects on dislocation glide in bcc metals from DFT calculations and machine-learning potentials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Arnaud Allera, Lisa Ventelon, Mihai-Cosmin Marinica, David Rodney, Laurent Proville
Quantum zero-point effects have been long proposed to explain a well-known discrepancy between the low-temperature flow stresses of body-centered cubic metals and corresponding atomistic models of plastic flow. Previous investigations on quantum effects relied on empirical interatomic potentials, which poorly reproduce dislocation energy landscapes compared to density functional theory (DFT) calculations. Here, we revisit this problem using DFT and machine-learning interatomic potentials (MLIPs). We show that while quantum effects do contribute to dislocation glide at low temperature, their magnitude is much lower than previously reported, and insufficient to reconcile atomistic predictions with experiments. Our results thus reopen a long-standing question and challenge for predictive atomistic modeling, on a fundamental property of crystals.
Materials Science (cond-mat.mtrl-sci)
Thermodynamic description of wealth inequality in the world
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
Klaus M. Frahm, Leonardo Ermann, Dima L. Shepelyansky
According to the recent Wealth Thermalization Hypothesis (WTH) the wealth inequality in the world is described by the Rayleigh-Jeans (RJ) thermal distribution of interacting agents in a society with social stratification. In this concept, the wealth layers of society are associated with energy levels from a nonlinear dynamical system conserving two integrals of motion being total energy and probability norm. This leads to RJ condensation and the formation of a huge poverty phase of low wealth and a tiny oligarchic phase that captures a main part of total society wealth. This RJ phenomenon has similarities with self cleaning in multimode optical fibers and constraint driven condensation in various physical systems. We analyze real Lorenz and Pareto curves for wealth of households in countries and the world, Gross Domestic Product of countries, market capitalization of companies at stock exchange of Hong Kong, Shanghai, London, bitcoin transactions, world trade between countries and show that the WTH theory gives a good description of these curves. On the basis of this comparison we argue that the RJ thermal distribution provides a universal description of wealth inequality in the world.
Statistical Mechanics (cond-mat.stat-mech), General Economics (econ.GN), Physics and Society (physics.soc-ph)
includes certain unpublished parts of arXiv:2512.06420, arXiv:2506.17720 ; 37 pages, 26 figures, includes also MDPI style files in subfolder Definitions
Theory of clusterization in orbitally degenerate transition-metal compounds driven by lattice instabilities
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
Soshun Ozaki, Kota Mitsumoto, Chisa Hotta
We derive an effective orbital-lattice model with quantum $ S=1$ degrees of freedom for transition-metal compounds, providing a microscopic understanding of cluster formation driven by the cooperative interplay of spin, orbital, and lattice degrees of freedom. Motivated by the trimerized phases observed in LiVS$ _2$ and LiVO$ 2$ , we consider a triangular-lattice three-orbital system with two electrons per site occupying the threefold-degenerate $ t{2g}$ manifold. Starting from a multiorbital Kanamori-Hubbard Hamiltonian, we project the low-energy sector onto the local $ S=1$ triplet manifold, in which two electrons occupy different orbitals according to Hund’s coupling. The resulting effective model exhibits exchange networks whose geometry is determined by the orbital configuration. However, the orbital-driven exchange interactions alone do not stabilize the experimentally observed trimer phase. We find that by incorporating ionic lattice displacements that modulate transfer integrals and induce bond-dependent exchange couplings on shortened and elongated bonds, the phase competition is qualitatively altered, leading to the robust stabilization of a trimerized ground state within a fully quantum-mechanical framework. We further show that a simplified orbital-lattice model, in which the spin-exchange energy is replaced by effective bond energies, faithfully reproduces the essential ground-state properties of the microscopic model. This reduced description enables large-scale finite-temperature simulations and reveals a rich sequence of thermal phase transitions, including first-order, second-order, and Kosterlitz-Thouless transitions into distinct spin-, orbital-, and lattice-ordered phases.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft)
Equilibrium cluster statistics of cooperative and anticooperative binding on finite one-dimensional rings
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
Thomas Alfonsi, Jérôme Dorignac, John Palmeri, Nils-Ole Walliser
We study equilibrium clustering in a finite one-dimensional lattice gas of $ L$ sites with periodic boundary conditions, as a minimal model for adsorption and binding on small ring-like substrates. Using a grand-canonical formulation with nearest-neighbor coupling, we derive exact finite-size expressions for the mean occupancy, the mean number of domain walls, and the mean number of clusters. Building on exact $ k$ -site correlation functions, we further derive expressions for the mean number of clusters of size $ k$ and for two complementary size statistics: the cluster-size distribution, and the site-weighted cluster-size distribution. These observables characterize how spatial organization changes across attractive (cooperative) and repulsive (anticooperative) interactions, and highlight finite-size and parity-dependent effects of the underlying lattice, the latter being particularly pronounced near half filling in small systems. To access larger lattices without enumerating all $ 2^L$ microstates, we also develop a cluster-based combinatorial formulation in which configurations are classified by cluster counts and sizes, reducing the effective state space to a set whose size scales with integer partitions, $ \approx e^{\sqrt{L}}$ , rather than with $ \approx e^{L}$ . Taken together, our results provide exact benchmarks for finite periodic systems and suggest experimentally relevant cluster observables that complement occupancy-based measures of cooperativity, with particular relevance for binding on ring-like substrates for biological assemblies.
Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
19 pages, 11 figures
Coupled spin dynamics in epitaxial trilayer heterostructures of ferrimagnetic garnet
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
A. Del Giacco, M.J. Gross, O. Wojewoda, L. Menna, T. Grossmark, P. Lauer, V. Levati, S. Kurdi, E. Albisetti, D. Petti, M. Urbanek, C.A. Ross
The magnetization dynamics of an all-garnet trilayer consisting of Y3Fe5O12/Y3Fe3Al2O12/Y3Fe5O12 (YIG/YIAG/YIG) is analysed. The two magnetic YIG layers, separated by a 4 nm thick paramagnetic YIAG layer, are coupled via dipolar interactions leading to the formation of hybrid magnon modes distinct from the modes found in a single YIG layer. The YIAG exchange-decouples the YIG layers while enabling lattice coherence, maintaining the low damping of the YIG. Both ferromagnetic resonance and micro-Brillouin light scattering measurements were used to characterize the sample and its hybrid dynamics, which showed excellent agreement with an analytical reciprocal space model of spin-wave dynamics and with micromagnetic modeling of a dipolarly coupled magnetic heterostructure.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
Universal scaling and relaxation in decaying turbulence of Bose gases
New Submission | Quantum Gases (cond-mat.quant-gas) | 2026-06-17 20:00 EDT
Arnol D. García-Orozco, Michelle A. Moreno-Armijos, Sarah Sab, Amilson Fritsch, Vanderlei Salvador Bagnato
Understanding the relaxation dynamics of isolated quantum systems remains a central challenge in nonequilibrium physics. In this short review, we discuss recent experimental and theoretical advances in universal dynamics of turbulent Bose gases, with particular emphasis on nonthermal fixed points and wave turbulence in our experimental system at the São Carlos Institute of Physics of the University of São Paulo. We highlight the emergence of self-similar scaling behavior and its connection to particle and energy transport across momentum scales. In addition, we discuss an approach in which a differential equation has a universal scaling solution, providing a practical framework for extracting universal exponents from limited regions of the momentum distribution. Furthermore, we recap experimental observations of direct and inverse cascades in a three-dimensional trapped Bose–Einstein condensate, revealing distinct relaxation stages governed by universal scaling laws. These results demonstrate that turbulence plays a key role in far-from-equilibrium dynamics, offering a unified perspective on transport processes and thermalization in quantum many-body systems.
Quantum Gases (cond-mat.quant-gas)
14 pages, 9 figures
Highly nonlinear Moiré exciton and trion polaritons
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
Arnab Barman Ray, Trevor Ollis, Fei Cheng, Adam L. Freidman, Aubrey T. Hanbicki, Anthony Nickolas Vamivakas
Moiré multi-layers of transition metal dichalcogenides have been shown to exhibit optical responses that are endowed with a richness that is absent in single monolayers. Much of this can be attributed to the Moiré superlattice that modulates the electronic landscape of these heterostructures. Strongly coupled layer-hybridized excitons in MoSe2/WS2 heterobilayers have been shown to exhibit enhanced optical nonlinearities. In this work we strongly couple layer hybridized excitons and trions in n-doped $ \text{MoSe}_2 / \text{WS}_2$ heterobilayers inside an optical microcavity. We find that the additional Lindhard screening from dopant electrons and the formation of trions result in a strikingly non-monotonic nonlinear response. The absence of electron capture in the Moiré superlattice plays a crucial role, promising very large second-order nonlinearities. In this work, trion polaritons manifest as high velocity hot polaritons, reaching nominal diffusion lengths approaching 100 microns.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Tunable Electronic and Transport Properties of Biphenylene via Fluorination and Disorder
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Lucas Soares Sousa, Felipe Crasto de Lima, Roberto Hiroki Miwa
Biphenylene (BPN) network is a newly synthesized 2D carbon allotrope hosting anisotropic Dirac electronic states. Here, we investigate how fluorination and correlated chemical disorder modify the electronic structure and charge transport of fluorinated biphenylene (F/BPN) using density functional theory, Wannier-based tight-biding Hamiltonian, and quantum transport simulations. We show that fluorination reshapes the transport response of BPN, producing concentration-dependent anisotropic conduction regimes. For pristine and ordered fluorinated systems, we identified the emergence of negative differential resistance (NDR) and a bias-induced inversion of the preferred transport direction, from armchair to zigzag and vice versa. In contrast, disorder suppresses the NDR, driving the system toward an approximately Ohmic transport regime. At high fluorine coverage, we further observed a nonmonotonic dependence of the armchair current on adatom concentration, which we attribute to the formation of correlated quasi-linear fluor conformation that promote armchair-oriented C-$ \pi$ transport channels while simultaneously suppressing transport along the zigzag direction. Our results demonstrate that correlated fluorination can be used as an active mechanism to engineer electronic transport.
Materials Science (cond-mat.mtrl-sci)
Cavity-enhanced superconducting response in an underdoped cuprate
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Angela Montanaro, Vadim Plastovets, Nitesh Khatiwada, Jacopo Fiore, Giacomo Jarc, Abdullah Alabbadi, Antonio Mastropasqua, Enrico Maria Rigoni, Shahla Y. Mathengattil, Simone Dal Zilio, Francesca Fassioli Olsen, Fabio Novelli, Stephan Winnerl, Michael A. Sentef, Dante M. Kennes, Andrew J. Millis, Francesco Piazza, Daniele Fausti
Superconductors carry electrical current without resistance when paired electrons condense into a coherent macroscopic quantum state. In underdoped cuprates, evidence suggests that pairing-related correlations and superconducting fluctuations can survive above the temperature at which global coherence is lost, pointing to phase fluctuations as a key limitation on superconductivity in this regime. Motivated by recent demonstrations of cavity-modified collective states in quantum materials, we investigate whether superconducting coherence can be stabilized by engineering the electromagnetic environment of the superconductor. We study an underdoped YBa$ _2$ Cu$ _3$ O$ _{7-\delta}$ thin film in a tunable terahertz cavity formed with a semi-transparent gold mirror. From temperature-dependent terahertz transmission measurements, we find that the cavity enhances the superconducting response below the critical temperature, with an increase of the inferred superfluid weight. The effect becomes more pronounced at smaller cavity lengths and is accompanied by an upward shift of the superconducting onset temperature. Calculations based on a cavity-coupled model for phase-fluctuating superconductors capture these trends and support an interpretation in terms of cavity-enhanced phase stiffness. These results showcase the potential of cavity engineering for designing emergent functionalities in correlated systems.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics), Quantum Physics (quant-ph)
Impact of dynamic electrostatic disorder on hole mobility in rubrene: a nonadiabatic molecular dynamics investigation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Jan Elsner, Samuele Giannini, Jochen Blumberger
High-mobility organic molecular crystals such as rubrene are important materials for organic electronics, yet a quantitatively predictive description of their charge transport properties remains challenging. Direct mixed quantum-classical nonadiabatic molecular dynamics simulations provide a promising route by explicitly propagating the charge carrier wavefunction, without assuming a specific transport mechanism. However, previous large-scale simulations of apolar molecular crystals have commonly neglected dynamic electrostatic disorder, since evaluation of electrostatic interactions is computationally demanding and the approximation appears plausible for apolar systems. Here, we use the damped shifted-force (DSF) real-space electrostatic summation method, combined with an efficient addition-subtraction scheme, to include dynamic electrostatic disorder in fragment orbital-based surface hopping (FOB-SH) simulations of room-temperature hole transport in rubrene. We find that electrostatic interactions increase the reorganization energy for (hypothetical) nearest neighbour hopping by 29 and 39 meV along the a and b-directions, respectively, relative to a baseline value of 152 meV obtained without electrostatics. In FOB-SH simulations, electrostatic interactions lead to increased site energy disorder, reducing the spatial extent of the hole wavefunction, as measured by a decrease in the inverse participation ratio from 13 to 9, and lowering the predicted mobility along the high-mobility direction from $ 35$ to $ 21~\mathrm{cm^2 V^{-1}s^{-1}}$ , in close agreement with experiment.
Materials Science (cond-mat.mtrl-sci)
Making complex CFTs real: The two-dimensional Potts model for $Q>4$ and complex $Q$
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2026-06-17 20:00 EDT
Jesper Lykke Jacobsen, Kay Joerg Wiese
The two-dimensional $ Q$ -state Potts model with real couplings has a first-order transition for $ Q>4$ . Starting from a triangular-lattice Potts model with two- and three-spin interactions, we study an equivalent loop model in which $ Q$ is a continuous parameter. By a combination of analytical and numerical arguments, we show that this loop model allows for the collision of a critical and a tricritical fixed point at $ Q=4$ . These then emerge as a pair of complex conformally invariant theories at $ Q>4$ , or even complex $ Q$ , for suitable complex coupling constants. We conjecture that all conformal data (such as the central charge, critical exponents, and three-point structure constants) can be obtained by analytic continuation of known exact results for the loop model with $ Q \le 4$ . This conjecture is checked, both for real $ Q>4$ and for $ Q \in \mathbb{C}$ , by extensive transfer-matrix computations and comparison to previous studies for $ Q=5$ .
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th)
44 pages, 211 figures
Double quantum spin Hall phase in bilayer ZrTe$_5$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Chao Chen Ye, Gábor Kalla, Jianting Ye, Jagoda Sławińska
Quantum spin Hall insulators (QSH) are topological materials that host helical edge states protected against backscattering, making them ideal candidates for dissipationless spin transport. Within the conventional $ \mathbb{Z}_2$ classification, only phases with an odd number of edge state pairs ($ \mathbb{Z}_2 = 1$ ) are topologically nontrivial, whereas even-channel systems ($ \mathbb{Z}_2 = 0$ ) lie beyond this framework but can host robust edge transport characterized by a spin Chern number. Experimentally accessible realizations of such phases remain rare, particularly in systems with sizeable band gaps. Here, we show that bilayer ZrTe$ _5$ realizes a double quantum spin Hall phase in its energetically most stable structure. Using first principles calculations, we demonstrate that uniaxial strain drives a transition from this phase to a conventional single pair QSH phase with $ \mathbb{Z}_2 = 1$ . The double QSH phase hosts two pairs of helical edge states, resulting in enhanced edge conductance and a quantized spin Hall response that remains robust over an energy window of up to $ \sim$ 100 meV. These results establish bilayer ZrTe$ _5$ as a tunable platform connecting conventional and double QSH phases within a single material. More broadly, they demonstrate that untwisted van der Waals bilayers can host topological phases beyond the conventional $ \mathbb{Z}_2$ classification.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other)
6 pages, 3 figures, supplement material not included
High-temperature ferromagnetism and antiferromagnetism in monolayer \ce{CrTe2}: Roles of strong spin-lattice coupling and charge doping
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2026-06-17 20:00 EDT
The interplay of structural, electronic, and magnetic degrees of freedom governs phase stability and critical temperatures in two-dimensional magnets. Controlling this coupling is essential for advancing fundamental understanding and spintronic applications. Combining first-principles calculations with Heisenberg Monte Carlo simulations, we reveal a rich magnetic phase diagram governed by the interplay of lattice strain and carrier density. These results provide a unified framework that reconciles diverse experimental reports on epitaxial layers and predicts a novel double-stripe antiferromagnetic phase, further stabilized by electron doping. Moreover, structural and electronic perturbations enable room-temperature ferromagnetism and antiferromagnetism. This magnetic evolution arises from competing, highly tunable direct and ligand-mediated exchange interactions in the presence of Ruderman-Kittel-Kasuya-Yosida coupling. By disentangling their individual contributions, we elucidate the underlying microscopic mechanisms, which transcends the conventional conduction electron picture. Finally, we quantify the colossal magnetoelastic response and identify zone-folded Raman modes that serve as unique experimental fingerprints for phase identification. Together, these results establish \ce{CrTe2} as a versatile platform for two-dimensional spintronics, where magnetic order and transition temperatures are tailorable via structural and electrical engineering.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
20 pages, 7 figures, Supplemental Material (17 pages)
Dynamical properties of ab initio water from machine-learning potentials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2026-06-17 20:00 EDT
P. Montero de Hijes, L. Neubeck, G. Kresse, C. Dellago
We assess the dynamical properties of liquid water predicted by several density functionals using machine-learning interatomic potentials. MACE models were trained for SCAN, RPBE-D3/zd, revPBE-D3/zd, revPBE0-D3/BJ, PBE0-D3/zd, and PBE0-D3/BJ using previously reported ab initio datasets. We compare translational, rotational, and viscous dynamics through time-correlation functions, which resolve relaxation processes across different timescales, and through the corresponding long-time kinetic coefficients. The diffusion coefficient, second-rank orientational relaxation time, and shear viscosity reveal systematic differences among functionals. Part of these differences can be rationalized as shifts along the phase diagram, as comparisons relative to each functionals melting temperature reduce the spread in the dynamical observables. Among the functionals considered, RPBE-D3/zd provides the best overall agreement with experiment. We therefore perform a broader validation of RPBE-D3/zd using a Behler–Parrinello neural-network potential over a wide range of temperatures, densities, and pressures. The model reproduces the magnitude and anomalous pressure dependence of the diffusion coefficient, gives generally good viscosities, and captures the temperature dependence of the rotational relaxation time.
Soft Condensed Matter (cond-mat.soft)
Learning Dynamics of Chain-of-Thought State Tracking in a Solvable Transformer Model
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2026-06-17 20:00 EDT
Niklas Forner, Marcel Kühn, Matthias Thamm, Bernd Rosenow
Chain-of-thought generation can turn a multi-step computation into a sequence of locally checkable state updates, but the training dynamics by which transformers acquire such updates remain poorly understood. We study this question in a solvable setting: a simplified one-block transformer trained by supervised next-token prediction on state sequences generated by composing permutations. The architecture separates fixed-lag action retrieval, learned by RoPE attention, from a specialized MLP logic module that applies the retrieved permutation to the current state. Using a statistical-physics mean-field description, we derive dynamics for three order parameters measuring attention retrieval, teacher-matrix alignment, and off-target logic overlap. These equations quantitatively match simulations for the order parameters and, combined with a logit-distribution approximation, qualitatively predict the sharp transition in final rollout accuracy. The analysis reveals staged learning: the logic module first learns a mixed heuristic; attention then locks onto the relevant action, enabling efficient MLP alignment. Together, these results provide a controlled mechanistic account of how attention-based retrieval and MLP-based logic co-develop during chain-of-thought state tracking.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Data Analysis, Statistics and Probability (physics.data-an)
10 pages, 3 figures
Anisotropic Short-Range Order Modulates Ferroelectric Switching in Wurtzite ScAlN Alloys
New Submission | Materials Science (cond-mat.mtrl-sci) | 2026-06-17 20:00 EDT
Shunda Chen, Xianchao Dong, Xiaochen Jin, Tianshu Li
Ferroelectric switching in wurtzite alloys is typically understood in terms of composition, strain, defects, and interfaces, while local chemical order is often neglected or treated as a secondary perturbation. Here we show that short-range order (SRO) is a previously overlooked microscopic variable that substantially influences the intrinsic switching barrier. Using first-principles canonical sampling, we find that wurtzite ScAlN develops a robust, highly anisotropic SRO that challenges the conventional random-alloy picture. This ordering suppresses in-plane Sc–N–Sc motifs while enhancing columnar mixed-cation chains along the polar $ c$ axis, reflecting the symmetry-distinct polar and basal directions of the wurtzite lattice and reorganizing its polar connectivity. Relative to random-alloy structures, SRO systematically increases the intrinsic switching barrier across a broad composition range. Motif-resolved analysis further identifies the population of columnar Sc–N–Al–N–Sc motifs as the primary structural descriptor underlying switching-barrier variations among configurations with different local order. These results establish anisotropic SRO as an independent degree of freedom for tuning ferroelectric switching. More broadly, they reveal how local chemical order can couple to the symmetry-distinct directions of a polar semiconductor lattice to modify functional behavior. Our findings lay a foundation for SRO engineering as a route to tailoring switching barriers without changing alloy composition.
Materials Science (cond-mat.mtrl-sci)
4 figures in main text; 6 figures in SI
Coherent effects in quantum transport models and their classical counterparts
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2026-06-17 20:00 EDT
N.S. Maslova, V.N. Mantsevich, I.M. Sokolov, P.I. Arseyev
We analyze the transport properties of quasiparticles locally excited at an initial time moment in several exactly solvable quantum models. It is revealed that, in the investigated quantum systems, the time-dependent probability distribution function (PDF) exhibits behavior similar to that of classical continuous-time random walk (CTRW) models, such as Lévy walks or diffusing diffusivity.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
14 pages, 4 figures
Superconductivity from interband coupling to ferroelectric quantum critical fluctuations in two dimensions
New Submission | Superconductivity (cond-mat.supr-con) | 2026-06-17 20:00 EDT
Sudip Kumar Saha, Jonathan Ruhman, Avraham Klein
Soft critical fluctuations associated with ferroelectric quantum phase transitions are typically transverse owing to their polar nature. This implies that the conventional density–density electron–phonon coupling to these modes is strongly suppressed, which is puzzling as a variety of materials exhibit enhanced superconductivity in the vicinity of ferroelectricity. An alternative coupling mechanism is an interband ``Stark’’-like coupling that connects bands of opposite parity. In the limit where one of the bands is far in energy, these processes generate an effective quadratic (two-phonon) coupling. In contrast, when both bands lie close to the Fermi energy, the resulting interaction develops singular behavior due to the additional gapless electronic states, motivating a detailed study into the dynamics of this effective two-phonon coupling. To this end, we construct the quantum critical Eliashberg theory for a two-dimensional system across a wide range of interband gap magnitudes, near the quantum critical point. We find that the critical temperature $ T_c$ is strongly enhanced relative to conventional BCS expectations. In the large-gap limit, the pairing kernel acquires higher-order logarithmic contributions, leading to a parametrically enhanced $ T_c$ governed by cubic and quadratic logarithmic terms. In the small-gap regime, the pairing scale exhibits a modified BCS-like form with an enhanced dependence on the inverse square root of the dimensionless coupling constant. The enhancement is due to the dynamics of the two-phonon pairing whose infrared cutoff is set by $ T_c$ , resulting in a significant enhancement of superconductivity compared to three-dimensional systems, where it is set by the Fermi energy. Our results elucidate the unique dynamical properties of effective two-phonon interactions, and may be relevant to layered compounds like Td-MoTe$ _2$ and doped SrTiO$ _3$ membranes.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 5 figures