CMP Journal 2025-08-28
Statistics
Nature Nanotechnology: 1
Science: 16
Physical Review Letters: 7
Physical Review X: 2
arXiv: 45
Nature Nanotechnology
Emission of nitrogen-vacancy centres in diamond shaped by topological photonic waveguide modes
Original Paper | Atom optics | 2025-08-27 20:00 EDT
Raman Kumar, Chandan, Gabriel I. López Morales, Richard Monge, Anton Vakulenko, Svetlana Kiriushechkina, Alexander B. Khanikaev, Johannes Flick, Carlos A. Meriles
As the ability to integrate single-photon emitters into photonic architectures improves, so does the need to characterize and understand their interaction. Here we use a scanning diamond nanocrystal to investigate the interplay between the emission of room-temperature nitrogen-vacancy (NV) centres and a proximal topological waveguide. In our experiments, NVs serve as local, spectrally broad light sources, which we exploit to characterize the waveguide bandwidth as well as the correspondence between the light injection site and the directionality of wave propagation. We find that near-field coupling to the waveguide influences the spectral shape and ellipticity of the NV photoluminescence, revealing nanostructured light fields through polarization and amplitude contrasts exceeding 50%, with a spatial resolution set by the nanoparticle size. Our results expand on the sensing modalities afforded by colour centres, highlighting novel opportunities for on-chip quantum optics devices that leverage topological photonics to optimally manipulate and read out single-photon emitters.
Atom optics, Optical properties of diamond
Science
Septal LYVE1+ macrophages control adipocyte stem cell adipogenic potential
Research Article | Tissue immunology | 2025-08-28 03:00 EDT
Xiaotong Yu, Yanan Hu, Hwee Ying Lim, Ziyi Li, Diego Adhemar Jaitin, Katharine Yang, Wan Ting Kong, Jiaqian Xu, David Alejandro Bejarano, Mathilde Bied, Lucie Orliaguet, Gowshika Rengasamy, Zachary Chow, Christopher Zhe Wei Lee, Josephine Lum, Jing Tian, Xiao-Meng Zhang, Honghao Liu, Shu Wen Tan, Jinmiao Chen, Peter See, Yuin-Han Loh, Benoit Malleret, Sonia Baig, M. Shabeer M. Yassin, Sue-Anne Ee Shiow Toh, Bernard Malissen, Xiujun Fu, Kenji Kabashima, Lai Guan Ng, Camille Blériot, Zhaoyuan Liu, Lingling Sheng, Dan-Ning Zheng, Junwen Qu, Nicolas Venteclef, Bing Su, Ido Amit, Andreas Schlitzer, Veronique Angeli, Florent Ginhoux, Svetoslav Chakarov
Tissue macrophages reside in anatomically distinct subtissular niches that shape their identity and function. In white adipose tissue (WAT), we identified three macrophage populations with distinct localization, turnover, and phenotypes. Septal adipose tissue macrophages (sATMs), marked by CD209b and lymphatic vessel endothelial hyaluronan receptor 1, were long-lived and positioned in close proximity to adipocyte stem cells (ASCs) within the WAT septum. Within this shared niche, sATMs instructed the differentiation of ASCs into white adipocytes through transforming growth factor-β1 (TGFβ1). Depletion of sATMs, or the selective loss of TGFβ1 within tissue-resident macrophages, redirected ASC fate toward thermogenic adipocytes, enhancing WAT beiging and protecting against diet-induced obesity. These findings highlight the role of a discrete, anatomically defined macrophage population that governs ASC fate and orchestrates adipose tissue expansion.
Land availability and policy commitments limit global climate mitigation from forestation
Research Article | Climate mitigation | 2025-08-28 03:00 EDT
Yijie Wang, Yakun Zhu, Susan C. Cook-Patton, Wenjuan Sun, Wen Zhang, Philippe Ciais, Tingting Li, Pete Smith, Wenping Yuan, Xudong Zhu, Josep G. Canadell, Xiaopeng Deng, Yifan Xu, Hao Xu, Chao Yue, Zhangcai Qin
Forestation (afforestation and reforestation) could mitigate climate change by sequestering carbon within biomass and soils. However, global mitigation from forestation remains uncertain owing to varying estimates of carbon sequestration rates (notably in soil) and land availability. In this study, we developed global maps of soil carbon change that reveal carbon gains and losses with forestation, primarily in the topsoil. Constraining land availability to avoid unintended albedo-induced warming and safeguard water and biodiversity (389 million hectares available for forestation globally) would sequester 39.9 petagrams of carbon by 2050, substantially below previous estimates. This estimate drops to 12.5 petagrams of carbon with land further limited to existing policy commitments (120 million hectares). Achieving greater mitigation requires expanding dedicated forestation areas and strengthening commitments from nations with considerable but untapped potential.
Seismic evidence for a highly heterogeneous martian mantle
Research Article | Planetary science | 2025-08-28 03:00 EDT
Constantinos Charalambous, W. Thomas Pike, Doyeon Kim, Henri Samuel, Benjamin Fernando, Carys Bill, Philippe Lognonné, W. Bruce Banerdt
A planet’s interior is a time capsule, preserving clues to its early history. We report the discovery of kilometer-scale heterogeneities throughout Mars’ mantle, detected seismically through pronounced wavefront distortion of energy arriving from deeply probing marsquakes. These heterogeneities, likely remnants of the planet’s formation, imply a mantle that has undergone limited mixing driven by sluggish convection. Their size and survival constrain Mars’ poorly known mantle rheology, indicating a high viscosity of 1021.3 to 1021.9 pascal-seconds and low temperature dependence, with an effective activation energy of 70 to 90 kilojoules per mole, suggesting a mantle deforming by dislocation creep. The limited mixing, coupled with ubiquitous, scale-invariant heterogeneities, reflects a highly disordered mantle, characteristic of the more primitive interior evolution of a single-plate planet, contrasting sharply with the tectonically active Earth.
Machine learning-based penetrance of genetic variants
Research Article | Medical genomics | 2025-08-28 03:00 EDT
Iain S. Forrest, Ha My T. Vy, Ghislain Rocheleau, Daniel M. Jordan, Ben O. Petrazzini, Girish N. Nadkarni, Judy H. Cho, Mythily Ganapathi, Kuan-Lin Huang, Wendy K. Chung, Ron Do
Accurate variant penetrance estimation is crucial for precision medicine. We constructed machine learning (ML) models for 10 diseases using 1,347,298 participants with electronic health records, then applied them to an independent cohort with linked exome data. Resulting probabilities were used to evaluate ML penetrance of 1648 rare variants in 31 autosomal dominant disease-predisposition genes. ML penetrance was variable across variant classes, but highest for pathogenic and loss-of-function variants, and was associated with clinical outcomes and functional data. Compared with conventional case-versus-control approaches, ML penetrance provided refined quantitative estimates and aided the interpretation of variants of uncertain significance and loss-of-function variants by delineating clinical trajectories over time. By leveraging ML and deep phenotyping, we present a scalable approach to accurately quantify disease risk of variants.
Selection at the GSDMC locus in horses and its implications for human mobility
Research Article | Horse evolution | 2025-08-28 03:00 EDT
Xuexue Liu, Yaozhen Jia, Jianfei Pan, Yanli Zhang, Ying Gong, Xintong Wang, Yuehui Ma, Nadir Alvarez, Lin Jiang, Ludovic Orlando
Horsepower revolutionized human history through enhanced mobility, transport, and warfare. However, the suite of biological traits that reshaped horses during domestication remains unclear. We scanned an extensive horse genome time series for selection signatures at 266 markers associated with key traits. We detected a signature of positive selection at ZFPM1–known to be a modulator of behavior in mice–occurring ~5000 years ago (ya), suggesting that taming was one of the earliest steps toward domestication of horses. Intensive selection at GSDMC began ~4750 ya with the domestication bottleneck, leading regulatory variants to high frequency by ~4150 ya. GSDMC genotypes are linked to body conformation in horses and to spinal anatomy, motor coordination, and muscular strength in mice. Our results suggest that selection on standing variation at GSDMC was crucial for the emergence of horses that could facilitate fast mobility in human societies ~4200 ya.
A hypoxia-responsive tRNA-derived small RNA confers renal protection through RNA autophagy
Research Article | Cell biology | 2025-08-28 03:00 EDT
Guoping Li, Lingfei Sun, Cuiyan Xin, Tian Hao, Prakash Kharel, Aidan C. Manning, Christopher L. O’Connor, Henry Moore, Shuwen Lei, Priyanka Gokulnath, Xinyu Yang, Ritin Sharma, Krystine Garcia-Mansfield, Priyadarshini Pantham, Chunyang Xiao, Hanna Y. Wang, Emeli Chatterjee, Seungbin Yim, Leo B. Ren, Michail Spanos, Hua Zhu, Haobo Li, Ji Lei, James F. Markmann, Louise C. Laurent, John J. Rossi, Oluwaseun Akeju, Quanhu Sheng, Ravi V. Shah, William A. Goddard, Todd M. Lowe, Patrick Pirrotte, Markus Bitzer, Pavel Ivanov, Joseph V. Bonventre, Saumya Das
Transfer RNA-derived small RNAs (tsRNAs or tDRs) perform a range of cellular functions. Here, we showed that tRNA-Asp-GTC-3’tDR, a hypoxia-induced tDR derived from the 3’ end of tRNA-Asp-GTC, activated autophagic flux in kidney cells and its silencing blocked autophagic flux. Functional gain-/loss-of-function studies in murine kidney disease models demonstrated a substantial renoprotective function of tRNA-Asp-GTC-3’tDR. Mechanistically, tRNA-Asp-GTC-3’tDR assembled stable G-quadruplex structures and sequestered pseudouridine synthase 7 (PUS7), preventing catalytic pseudouridylation of histone mRNAs. The resulting pseudouridylation deficiency directed histone mRNAs to the autophagosome-lysosome pathway, triggering RNA autophagy. This tDR-induced RNA autophagy pathway was activated during murine and human kidney diseases, suggesting clinical relevance. Thus, tRNA-Asp-GTC-3’tDR plays a role in regulating RNA autophagy, which helps to maintain homeostasis in kidney cells and protects against kidney injury.
Deep generative models design mRNA sequences with enhanced translational capacity and stability
Research Article | 2025-08-28 03:00 EDT
He Zhang, Hailong Liu, Yushan Xu, Haoran Huang, Yiming Liu, Jia Wang, Yan Qin, Haiyan Wang, Lili Ma, Zhiyuan Xun, Xuzhuang Hou, Timothy K. Lu, Jicong Cao
Despite the success of mRNA COVID-19 vaccines, extending this modality to more diseases necessitates substantial enhancements. We present GEMORNA, a generative RNA model that utilizes Transformer architectures tailored for mRNA coding sequences (CDSs) and untranslated regions (UTRs), to design novel mRNAs with enhanced expression and stability. GEMORNA-designed full-length mRNAs exhibited up to a 41-fold increase in firefly luciferase expression compared to an optimized benchmark in vitro. GEMORNA-generated therapeutic mRNAs achieved up to a 15-fold enhancement in human erythropoietin (EPO) expression and substantially elicited antibody titers of COVID vaccine in mice. Additionally, GEMORNA’s versatility extends to circular RNA, substantially enhancing circular EPO expression and boosting anti-tumor cytotoxicity in CAR-T cells. These advancements highlight deep generative AI’s vast potential for mRNA therapeutics.
Transcription factors SP5 and SP8 drive primary cilia formation in mammalian embryos
Research Article | Cell biology | 2025-08-28 03:00 EDT
Yinwen Liang, Richard Koche, Ravindra B. Chalamalasetty, Daniel N. Stephen, Mark W. Kennedy, Zhimin Lao, Yunong Pang, Ying-Yi Kuo, Moonsup Lee, Francisco Pereira Lobo, Xiaofeng Huang, Anna-Katerina Hadjantonakis, Terry P. Yamaguchi, Kathryn V. Anderson, Alexandra L. Joyner
Although specific transcription factors (TFs) are known to regulate cell fate decisions, the degree to which they can stimulate formation of specific cell organelles is less clear. We used a multiomics comparison of the transcriptomes of ciliated and unciliated embryonic cells to identify TFs up-regulated in ciliated cells. We also used conditional genetics in mouse embryos and stem cells and found that the TFs SP5 and SP8 regulate cilia formation and gene expression. In embryos lacking Sp5 and Sp8, primary and motile cilia were shorter than normal and reduced in number across cell types, contributing to situs inversus and hydrocephalus. Moreover, expression of SP8 was sufficient to induce primary cilia in unciliated cells. This work will facilitate the study of cilia assembly using stem cell models and promote further understanding of human ciliopathies.
Columbian mammoth mitogenomes from Mexico uncover the species’ complex evolutionary history
Research Article | 2025-08-28 03:00 EDT
Eduardo Arrieta-Donato, Ángeles Tavares-Guzmán, Miriam Bravo-Lopez, Viridiana Villa-Islas, Alejandra Castillo-Carbajal, Wenxi Li, Ernesto Garfias-Morales, Rigoberto Padilla-Bustos, Marcela Sandoval-Velasco, Luis Córdoba-Barradas, Ruben Manzanilla-López, J. Camilo Chacón-Duque, Alejandro López-Jímenez, Mashaal Sohail, Joaquín Arroyo-Cabrales, María C. Ávila-Arcos, Federico Sánchez-Quinto
Paleogenomic studies suggest that Mammuthus columbi derives from an ancient hybridization between Mammuthus primigenius and Mammuthus trogontherii. While its habitat spanned from North to Central America, available genetic data are limited to temperate regions, leaving gaps in knowledge of the species’ demographic history on the continent. In this study, we generated 61 capture-enriched M. columbi mitogenomes from the Basin of Mexico, in Central Mexico. Our analysis reveals that these mitogenomes belong to a mitochondrial lineage distinct from other North American mammoths. These divergent mitogenomes suggest a deep population structure in their ancestors, and challenge prior assumptions based on geographically restricted samples. Our findings underscore the importance of wider spatial sampling to reconstruct mammoths’ evolutionary history and demonstrate the feasibility of studying megafauna from tropical latitudes.
Yellowstone’s free-moving large bison herds provide a glimpse of their past ecosystem function
Research Article | Restoration ecology | 2025-08-28 03:00 EDT
Chris Geremia, E. William Hamilton, Jerod A. Merkle
Although momentum is building to restore bison across North America, most efforts focus on small, managed herds, leaving unclear how large, migrating herds shape landscapes and whether their effects enhance or degrade ecosystems. We assessed carbon and nitrogen dynamics across the northern Yellowstone ecosystem, where one of the last remaining large migratory populations resides. Bison stabilized net aboveground production while accelerating nitrogen turnover, increasing aboveground nitrogen pools while carbon pools remained stable, which improved landscape nutritional quality. Effects were strongest in wet, nutrient-rich habitats that received higher bison densities and grazing than is recommended in rangeland management, while soil and plant conditions suggested landscape resilience. Restoration should embrace heterogeneity in densities and effects across habitats and spatial scales beyond those guiding most current recovery efforts.
Somatotopic organization of brainstem analgesic circuitry
Research Article | Pain | 2025-08-28 03:00 EDT
Lewis S. Crawford, Fernando A. Tinoco Mendoza, Rebecca V. Robertson, Noemi Meylakh, Paul M. Macey, Kirsty Bannister, Tor D. Wager, Vaughan G. Macefield, Kevin A. Keay, Luke A. Henderson
The lateral periaqueductal gray (lPAG) evokes somatotopically appropriate defensive behaviors, including an analgesia that allows the animal to escape or fight unimpeded. Whether the lPAG and its descending targets are also able to drive somatotopically specific analgesic responses is not known. In this work, we performed ultrahigh-field functional magnetic resonance imaging of the lPAG in 93 participants during a placebo analgesia paradigm performed at different body locations. We found that analgesic responses are somatotopically organized in the lPAG and its descending outputs to the rostral ventromedial medulla. These data show that the PAG can regulate analgesic responses in a highly spatially localized manner and thus has the ability to mediate body site-selective control over pain.
Launching by cavitation
Research Article | Robotics | 2025-08-28 03:00 EDT
Dalei Wang, Zixiao Liu, Hongping Zhao, Huanqi Qin, Gongxun Bai, Chi Chen, Pengju Shi, Yingjie Du, Yusen Zhao, Wei Liu, Dan Wang, Guoquan Zhou, Ximin He, Chaoqing Dai
Cavitation, characterized by formation of vapor bubbles in a low-pressure or high-temperature region of a liquid, is often destructive, but it can be harnessed for actuators and robots. We exploit cavitation to accumulate substantial energy in superheated liquids by suppressing its immediate release until reaching a stability limit. The energetic, unstable bubbles collapse violently, producing a burst of high power and force that initiates motion. Notably, a millimeter-scale device launched by cavitation can jump to a height of 1.5 meters–reaching a 12 meters per second (m/s) peak velocity, a 7.14 × 104 m/s2 acceleration, and a 0.64% energy efficiency–and can also swim on water at 12 centimeters per second. Cavitation-based launching works with a broad range of device materials, liquid media, stimuli, and operational environments.
Heavily polluted Tijuana River drives regional air quality crisis
Research Article | Air pollution | 2025-08-28 03:00 EDT
Benjamin Rico, Kelley C. Barsanti, William C. Porter, Karolina Cysneiros de Carvalho, Paula Stigler-Granados, Kimberly A. Prather
Industrial chemicals and untreated sewage have polluted the Tijuana River for decades, recently causing >1300 consecutive days of California beach closures. In summer 2024, wastewater flows surged to millions of gallons per day despite no rain, enhancing water-to-air transfer of hydrogen sulfide (H2S) and other toxic gases at a turbulent hotspot. High wastewater flows and low winds led to nighttime H2S peaks, reaching 4500 parts per billion (ppb)–exceeding typical urban levels of <1 ppb. H2S levels and community malodor reports were strongly correlated (correlation coefficient r = 0.92), validating long-dismissed community voices and highlighting an environmental injustice. This study demonstrates that poor water quality can substantially affect air quality–although rarely included in air quality models and health assessments–with far-reaching implications as polluted waterways increase globally.
Architecture of the UBR4 complex, a giant E4 ligase central to eukaryotic protein quality control
Research Article | Proteostasis | 2025-08-28 03:00 EDT
Daniel B. Grabarczyk, Julian F. Ehrmann, Paul Murphy, Woo Seok Yang, Robert Kurzbauer, Lillie E. Bell, Luiza Deszcz, Jana Neuhold, Alexander Schleiffer, Alexandra Shulkina, Juyeon Lee, Jin Seok Shin, Anton Meinhart, Gijs A. Versteeg, Eszter Zavodszky, Hyun Kyu Song, Ramanujan S. Hegde, Tim Clausen
Eukaryotic cells have evolved sophisticated quality control mechanisms to eliminate aggregation-prone proteins that compromise cellular health. Central to this defense is the ubiquitin-proteasome system, where UBR4 acts as an essential E4 ubiquitin ligase, amplifying degradation marks on defective proteins. Cryo-electron microscopy analysis of UBR4 in complex with its cofactors KCMF1 and CALM1 reveals a massive 1.3-megadalton ring structure, featuring a central substrate-binding arena and flexibly attached catalytic units. Our structure shows how UBR4 binds substrate and extends lysine-48-specific ubiquitin chains. Efficient substrate targeting depends on both preubiquitination and specific N-degrons, with KCMF1 acting as a key substrate filter. The architecture of the E4 megacomplex is conserved across eukaryotes, but species-specific adaptations allow UBR4 to perform its precisely tuned quality control function in diverse cellular environments.
Classical-decisive quantum internet by integrated photonics
Research Article | Quantum networks | 2025-08-28 03:00 EDT
Yichi Zhang, Robert Broberg, Alan Zhu, Gushu Li, Li Ge, Jonathan M. Smith, Liang Feng
Classical and quantum technologies have traditionally been viewed as orthogonal, with classical systems being deterministic and quantum systems inherently probabilistic. This distinction hinders the development of a scalable quantum internet even as the global internet continues expanding. We report a classical-decisive quantum internet architecture in which the integration of quantum information into advanced photonic technologies enables efficient entanglement distribution over a commercially deployed fiber network. On-chip precise synchronization between classical headers and quantum payloads enables dynamic routing and networking of high-fidelity entanglement guided by classical light. The quantum states are preserved through real-time error mitigation, relying solely on classical signal readout without disturbing quantum information. These classical-decisive features demonstrate a practical path to a scalable quantum internet using existing network infrastructure and operating systems.
Deciphering icosahedra structural evolution with atomically precise silver nanoclusters
Research Article | Nanomaterials | 2025-08-28 03:00 EDT
Feng Hu, Gaoyuan Yang, Lu-Ming Zheng, Gui-Jie Liang, Quan-Ming Wang
Determining the atomic structure of nanoparticles (NPs) is critical for understanding their structural evolution and properties. However, controlling the growth of multiply-twinned metal NPs remains challenging because of numerous competing pathways. In this work, we report the synthesis of two giant silver icosahedral nanoclusters, [Ag213(C≡CR1)96]5- and [Ag429Cl24(C≡CR2)150]5- (Ag213 and Ag429, R1 =3,4,5-F3C6H2 and R2 = 4-CF3C6H4), achieved through ligand engineering and kinetic control. Single-crystal x-ray diffraction reveals that Ag213 and Ag429 have multilayered icosahedral Ag141 |(Ag13@Ag42@Ag86) and Ag297 (Ag13@Ag42@Ag92@Ag150) cores, respectively. Notably, Ag429 with 260 valence electrons is the largest Ag0-containing nanocluster reported to date. These two giant silver nanoclusters are metallic in nature, as confirmed by their plasmonic absorption and pump-power-dependent excited-state dynamics. Their atomically precise structures support the layer-by-layer evolution from nuclei to seeds of silver icosahedra.
Physical Review Letters
Enhancing Revivals Via Projective Measurements in a Quantum Scarred System
Research article | Entanglement entropy | 2025-08-27 06:00 EDT
Alessio Paviglianiti and Alessandro Silva
Quantum many-body scarred systems exhibit atypical dynamical behavior, evading thermalization and featuring periodic state revivals. In this Letter, we investigate the impact of projective measurements on the dynamics in the scar subspace for the paradigmatic PXP model, revealing that they can either disrupt or enhance the revivals. Local measurements performed at random times rapidly erase the system’s memory of its initial conditions, leading to fast steady state relaxation. In contrast, a periodic monitoring amplifies recurrences and preserves the coherent dynamics over extended timescales. We identify a measurement-induced phase resynchronization, countering the natural dephasing of quantum scars, as the key mechanism underlying this phenomenon.
Phys. Rev. Lett. 135, 090402 (2025)
Entanglement entropy, Quantum measurements, Quantum scars
Observation of Near-Critical Kibble-Zurek Scaling in Rydberg Atom Arrays
Research article | Quantum phase transitions | 2025-08-27 06:00 EDT
Tao Zhang, Hanteng Wang, Wenjun Zhang, Yuqing Wang, Angrui Du, Ziqi Li, Yujia Wu, Chengshu Li, Jiazhong Hu, Hui Zhai, and Wenlan Chen
The Kibble-Zurek scaling reveals the universal dynamics when a system is linearly ramped across a symmetry-breaking phase transition. However, in reality, inevitable finite-size effects or symmetry-breaking perturbations can often smear out the critical point and render the phase transition into a smooth crossover. In this Letter, we show experimentally that the precise Kibble-Zurek scaling can be retained in the near-critical crossover regime, not necessarily crossing the critical point strictly. The key ingredient to achieving this near-critical Kibble-Zurek scaling is that the system size and the symmetry-breaking field must be appropriately scaled following the variation of ramping speeds. The experiment is performed in a reconfigurable Rydberg atom array platform, where the Rydberg blockade effect induces a ${Z}_{2}$ symmetry-breaking transition. The atom array platform enables precise control of the system size and the zigzag geometry as a symmetry-breaking field. Therefore, we can demonstrate notable differences in the precision of the Kibble-Zurek scaling with or without properly scaling the system size and the zigzag geometry. Our results strengthen the Kibble-Zurek scaling as an increasingly valuable tool for investigating phase transition in quantum simulation platforms.
Phys. Rev. Lett. 135, 093403 (2025)
Quantum phase transitions, Rydberg atoms & molecules, Ultracold gases
Moir'e-Orbital-Resolved Excitonic Mott Insulating States and Their Optical and Electric Control in van der Waals Heterostructures
Research article | Excitons | 2025-08-27 06:00 EDT
Lanyu Huang, Cuihuan Ge, Boyi Xu, Yufan Wang, Siyao Li, Xinyi Luo, Haipeng Zhao, Danliang Zhang, Zhouxiaosong Zeng, Qingjun Tong, Dong Li, Xiaoli Zhu, Kai Braun, Tingge Gao, Xiao Wang, and Anlian Pan
Moir'e potential formed in van der Waals heterostructures is predicted to feature multiple local minima functioning as orbital degree of freedom, which is an important ingredient for understanding intriguing strong correlation phenomena. However, an experimental demonstration of this moir'e-orbital enabled quantum state engineering is still unexplored. Here, we report clear evidence of moir'e-orbital resolved excitonic Mott insulating states in multiannealing H-type ${\mathrm{WSe}}{2}/{\mathrm{WS}}{2}$ heterobilayers and demonstrate their application in generating spatially ordered excitonic quantum phases. This moir'e orbital is evidenced by interlayer exciton emissions with an energy separation of $\sim 65\text{ }\text{ }\mathrm{meV}$ and further supported by our multiple field-dependent characterizations. Remarkably, the moir'e orbital allows a sequential formation of correlated Mott insulating states, with the extracted onsite Hubbard interaction reaching $\sim 30\text{ }\text{ }\mathrm{meV}$. A combined optical and electric doping allows control of strongly correlated quantum phases with various spatially ordered fermionic-bosonic orbital components.
Phys. Rev. Lett. 135, 096902 (2025)
Excitons, Optoelectronics, Valleytronics, 2-dimensional systems, Strongly correlated systems, Superlattices, Transition metal dichalcogenides
Nonlinearity-Induced Fractional Thouless Pumping of Solitons
Research article | Chern insulators | 2025-08-27 06:00 EDT
Yu-Liang Tao, Yongping Zhang, and Yong Xu
Recent studies have shown that a soliton can be fractionally transported by slowly varying a system parameter over one period in a nonlinear system. This phenomenon is attributed to the nontrivial topology of the corresponding energy bands of a linear Hamiltonian. Here we find the occurrence of fractional Thouless pumping of solitons in a nonlinear off-diagonal Aubry-Andr'e-Harper model. Surprisingly, this happens despite the fact that all the energy bands of the linear Hamiltonian are topologically trivial, indicating that nonlinearity can induce fractional Thouless pumping of solitons. Specifically, our results show that a soliton can be pumped across one unit cell over one, two, three, or four pump periods, implying an average displacement of 1, $1/2$, $1/3$, or $1/4$ unit cells per cycle, respectively. We attribute these behaviors to changes in on-site potentials induced by a soliton solution, leading to the nontrivial topology for the modified linear Hamiltonian. Given that our model relies solely on varying nearest-neighbor hoppings, it is readily implementable on existing state-of-the-art photonic platforms.
Phys. Rev. Lett. 135, 097202 (2025)
Chern insulators, Optical solitons, Nonlinear waves, Solitons
Pseudogiant Number Fluctuations and Nematic Order in Microswimmer Suspensions
Research article | Biological fluid dynamics | 2025-08-27 06:00 EDT
Ismail El Korde, Dóra Bárdfalvy, Jason M. Lewis, Alexander Morozov, Cesare Nardini, and Joakim Stenhammar
Giant number fluctuations (GNFs), whereby the standard deviation $\mathrm{\Delta }N$ in the local number of particles $\langleN\rangle$ grows faster than $\sqrt{\langleN\rangle}$, are a hallmark property of dry active matter systems with orientational order, such as a collection of granular particles on a vibrated plate. This contrasts with momentum-conserving (‘’wet’’) active matter systems, such as suspensions of swimming bacteria, where no theoretical prediction of GNFs exist, although numerous experimental observations of such enhanced fluctuations have been reported. In this Letter, we numerically confirm the emergence of super-Gaussian number fluctuations in a three-dimensional suspension of pusher microswimmers undergoing a transition to collective motion. These fluctuations emerge sharply above the transition, but only for sufficiently large values of the bacterial persistence length ${\ell }{p}={v}{s}/\lambda $, where ${v}{s}$ is the bacterial swimming speed and $\lambda $ the tumbling rate. Crucially, these ‘’pseudo-GNFs’’ differ from true GNFs, as they only occur on length scales shorter than the typical size $\xi $ of nematic patches in the collective motion state, which is in turn proportional to the single-swimmer persistence length ${\ell }{p}$. Our results thus suggest that observations of enhanced density fluctuations in biological active matter systems actually represent transient effects that decay away beyond mesoscopic length scales and raises the question to what extent ‘’true’’ GNFs with universal properties can exist in the presence of fluid flows.
Phys. Rev. Lett. 135, 098302 (2025)
Biological fluid dynamics, Collective behavior, Flocking, Living matter & active matter, Phase transitions, Bacteria, Lattice-Boltzmann methods
Comment on ‘’Aharonov-Bohm Phase Is Locally Generated Like All Other Quantum Phases’’
| 2025-08-27 06:00 EDT
Shan Gao
Phys. Rev. Lett. 135, 098901 (2025)
Reply to ‘’Comment on Aharonov-Bohm Phase Is Locally Generated Like All Other Quantum Phases’’
| 2025-08-27 06:00 EDT
Chiara Marletto and Vlatko Vedral
Phys. Rev. Lett. 135, 098902 (2025)
Physical Review X
Microscopic Imprints of Learned Solutions in Tunable Networks
Research article | Collective behavior in networks | 2025-08-27 06:00 EDT
Marcelo Guzman, Felipe Martins, Menachem Stern, and Andrea J. Liu
Physical constraints on networks, such as electrical resistor networks that learn on their own, offer interpretable insights into how learning tasks are performed and suggest a universal framework that extends to mechanical and biological systems.
Phys. Rev. X 15, 031056 (2025)
Collective behavior in networks, Learning theory, Self-organized systems, Disordered systems
Magnetoelectric Control of Helical Light Emission in a Moiré Chern Magnet
Research article | Flat bands | 2025-08-27 06:00 EDT
Eric Anderson, Heonjoon Park, Kaijie Yang, Jiaqi Cai, Takashi Taniguchi, Kenji Watanabe, Liang Fu, Ting Cao, Di Xiao, and Xiaodong Xu
Efficient, all-electrical control of magnetism and light polarization in twisted bilayer MoTe2 demonstrates a way to link magnetic memory and optical communication in one device and offers a new tuning knob for manipulating zero-field anyons.
Phys. Rev. X 15, 031057 (2025)
Flat bands, Magnetoelectric effect, Quantum anomalous Hall effect, Spintronics, Topological materials, Twistronics, Valleytronics, Chern insulators, Ferromagnets, Magnetic semiconductors, Photoluminescence
arXiv
Non-Hermitian edge burst of sound
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Hong-Yu Zou, Bing-Bing Wang, Yong Ge, Ke-Qi Zhao, Yu-Qi Chen, Hong-Xiang Sun, Shou-Qi Yuan, Haoran Xue, Baile Zhang
Non-Hermitian band topology can give rise to phenomena with no counterparts in Hermitian systems. A well-known example is the non-Hermitian skin effect (NHSE), where Bloch eigenstates localize at a boundary, induced by a nontrivial spectrum winding number. In contrast, recent studies on lossy non-Hermitian lattices have uncovered an unexpected boundary-localized loss probability-a phenomenon that requires not only non-Hermitian band topology but also the closure of the imaginary (dissipative) gap. Here, we demonstrate the non-Hermitian edge burst in a classical-wave metamaterial: a lossy nonreciprocal acoustic crystal. We show that, when the imaginary gap remains closed, edge bursts can occur at the right boundary, left boundary, or both boundaries simultaneously, all under the same non-Hermitian band topology; the latter scenario is known as a bipolar edge burst. The occurrence of each scenario depends on the number and location of the imaginary gap closure points in the eigenenergy spectra. These findings generalize the concept of edge burst from quantum to classical wave systems, establish it as an intrinsic material property, and enrich the physics of the complex interplay between non-Hermitian band topology and other physical properties in non-Hermitian systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Three-Dimensional Continuous Multi-Walled Carbon Nanotubes Network-Toughened Diamond Composite
New Submission | Other Condensed Matter (cond-mat.other) | 2025-08-28 20:00 EDT
Jiawei Zhang, Keliang Qiu, Tengfei Xu, Xi Shen, Junkai Li, Fengjiao Li, Richeng Yu, Huiyang Gou, Duanwei He, Liping Wang, Zhongzhou Wang, Guodong Li, Yusheng Zhao, Ke Chen, Fang Hong, Ruifeng Zhang, Xiaohui Yu
Enhancing the fracture toughness of diamond while preserving its hardness is a significant challenge. Traditional toughening strategies have primarily focused on modulating the internal microstructural units of diamonds, including adjustments to stacking sequences, faults, nanotwinning, and the incorporation of amorphous phases, collectively referred to as intrinsic toughening. Here, we introduce an extrinsic toughening strategy to develop an unparalleled tough diamond composite with complex and abundant sp2-sp3 bonding interfaces, by incorporating highly dispersed multi-walled carbon nanotubes (MWCNTs) into the gaps of diamond grains to create a three-dimensional (3D) continuous MWCTNs network-toughen heterogeneous structure. The resultant composite exhibits a hardness of approximately 91.6 GPa and a fracture toughness of roughly 36.4 MPa.m1/2, which is six times higher than that of synthetic diamond and even surpasses that of tungsten alloys, surpassing the benefits achievable through intrinsic toughening alone. The remarkable toughening behavior can be attributed to the formation of numerous mixed sp2-sp3 bonding interactions at the 3D continuous network MWCNTs/diamond interfaces, which facilitate efficient energy dissipation. Our 3D continuous network heterogeneous structure design provides an effective approach for enhancing the fracture toughness of superhard materials, offering a new paradigm for the advanced composite ceramics.
Other Condensed Matter (cond-mat.other), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
No-go theorem for single time-reversal invariant symmetry-protected Dirac fermions in 3+1d
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-28 20:00 EDT
Lei Gioia, Anton A. Burkov, Taylor L. Hughes
We employ a general method, known as anomaly-matching, to derive new no-go theorems of fermionic lattice models. For our main result, we show that time-reversal invariant 3+1d lattice systems (such as Dirac and Weyl semimetals) can never admit a lone low-energy symmetry-protected Dirac fermion (or node), i.e., it must always come in higher muliplets or be fine-tuned. This theorem holds for both non-interacting and interacting systems as long as the electromagnetic $ U(1){V,{\rm UV}}$ symmetry is a normal subgroup of the microscopic symmetry group $ G{\mathrm{UV}}$ ; a condition that is ubiquitous in physical $ U(1)_{V,{\rm UV}}$ preserving lattice models. To show that our theorems are tight, we also explore both well-known and new systems that are converses of the no-go theorem, obtained by forfeiting certain assumptions such as a broken time-reversal symmetry (magnetic Weyl semimetal), a non-compact non-on-site $ U(1)$ (almost local Dirac node model), no-symmetry protection (fine-tuned Dirac semimetal), or multiple low-energy Dirac nodes (time-reversal invariant Weyl and Dirac semimetals). We will also explicitly demonstrate that, while this theorem strictly prohibits single time-reversal invariant symmetry-protected Dirac node, it does allow for other odd numbers of Dirac nodes under certain circumstances, such as three Dirac nodes in the Fu-Kane-Mele diamond lattice model. This is akin to the Nielsen-Ninomiya theorem for an odd number of differently-charged chiral fermions, whose lattice realizations are allowed if certain anomaly cancellation conditions are met.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph)
24+11 pages, 6 figures
Thermodynamics in a split Hilbert space: Quantum impurity at the edge of a one-dimensional superconductor
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-28 20:00 EDT
Pradip Kattel, Abay Zhakenov, Natan Andrei
We present a thermodynamic description of a single magnetic impurity at the edge of a superconducting wire. The impurity exhibits four phases $ \unicode{x2014}$ Kondo, Yu-Shiba-Rusinov (YSR) I and II, and local moment $ \unicode{x2014}$ a phase diagram richer than in the gapless case, contrary to the expectation that the effects of impurities in gapped hosts are less consequential. We derive the impurity contribution to free energy $ F_{\rm imp}(T)$ and entropy in each phase: in Kondo phase, the entropy flows monotonically from $ \ln 2$ (UV) to 0 (IR) with critical exponents same as that of the conventional Kondo model; in YSR phases, thermal activation of a midgap bound state produces entropy overshoots above $ \ln 2$ , saturating to $ \ln 2$ at high $ T$ and approaching either 0 or $ \ln 2$ at low $ T$ depending on whether impurity is screened or not; in the local-moment phase the impurity remains effectively decoupled, with entropy near $ \ln 2$ , with some intermediate-temperature features that progressively fade as $ \delta \to 0$ . These behaviors, including the entropy overshoots in the YSR and local-moment phases, stem from a splitting of the Hilbert space into distinct excitation towers: one in the Kondo phase, two in YSRI, and three in YSRII and the local-moment phase. Resolving these tower structures and thereby going beyond conventional TBA yields closed-form analytic expressions for the impurity contribution to the free energy and entropy across the entire phase diagram.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph), Quantum Physics (quant-ph)
5+22 pages, 3+9 figures
Thermodynamics in a split Hilbert space: Quantum impurity at the edge of the Heisenberg chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-28 20:00 EDT
Abay Zhakenov, Pradip Kattel, Natan Andrei
We study the isotropic spin-$ \frac{1}{2}$ Heisenberg chain with a single edge-coupled impurity of arbitrary exchange strength $ J$ . The model exhibits four impurity phases. For antiferromagnetic couplings ($ J>0$ ): a \textit{Kondo phase} at weak $ J$ , where the impurity is screened by many-body excitations and the impurity entropy decreases monotonically from $ \ln 2$ at $ T \to \infty$ to $ 0$ at $ T\to 0$ ; and an \textit{antiferromagnetic bound-mode (ABM) phase} at strong $ J$ , where the impurity screened by an exponentially localized bound mode drives $ S_{\mathrm{imp}}(T)$ nonmonotonically, with undershoots below zero at intermediate temperatures, while tending to $ \ln 2$ as $ T \to \infty$ and to $ 0$ as $ T \to 0$ . For ferromagnetic couplings ($ J<0$ ): a local-moment (LM) phase at weak $ |J|$ , where the impurity remains unscreened with $ S_{\mathrm{imp}}\to \ln 2$ as $ T \to 0$ but exhibits shallow undershoots at intermediate scales; and a \textit{ferromagnetic bound-mode (FBM) phase} at strong $ |J|$ , where $ S_{\mathrm{imp}}=\ln 2$ in both UV and IR limits, yet develops an intermediate-temperature undershoot. We provide an analytic understanding of this behavior, showing that the undershoots originate from the fractionalization of the Hilbert space into several towers of states: for antiferromagnetic couplings this occurs only at strong $ J$ , driven by boundary-localized bound modes, while for ferromagnetic couplings undershoots occur for all $ J<0$ , becoming deeper with increasing $ |J|$ and vanishing as $ J\to 0^{-}$ . These bound modes screen the impurity. Incorporating the bound modes and edge states provides a complete analytic understanding of this phenomenon and yields closed expressions for the impurity contribution to free energy and entropy that are valid across all phases. These are checked and found to be in excellent agreement with tensor network and exact diagonalization results.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph), Exactly Solvable and Integrable Systems (nlin.SI), Quantum Physics (quant-ph)
The abstract is shortened. Full abstract is in the paper
Quantification of mobile ions in perovskite solar cells with thermally activated ion current measurements
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Moritz C. Schmidt, Agustin O. Alvarez, Riccardo Pallotta, Biruk A. Seid, Jeroen J. de Boer, Jarla Thiesbrummel, Felix Lang, Giulia Grancini, Bruno Ehrler
Mobile ions play a key role in the degradation of perovskite solar cells, making their quantification essential for enhancing device stability. Various electrical measurements have been applied to characterize mobile ions. However, discerning between different ionic migration processes can be difficult. Furthermore, multiple measurements at different temperatures are usually required to probe different ions and their activation energies. Here, we demonstrate a new characterization technique based on measuring the thermally activated ion current (TAIC) of perovskite solar cells. The method reveals density, diffusion coefficient, and activation energy of mobile ions within a single temperature sweep and offers an intuitive way to distinguish mobile ion species. We apply the TAIC technique to quantify mobile ions of MAPbI3 and triple-cation perovskite solar cells. We find a higher activation energy and a lower diffusion coefficient in the triple-cation devices. TAIC measurements are a simple yet powerful tool to better understand ion migration in perovskite solar cells.
Materials Science (cond-mat.mtrl-sci)
Non-Hermitian Josephson junctions with four Majorana zero modes
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-28 20:00 EDT
Josephson junctions formed by finite-length topological superconductors host four Majorana zero modes when the phase difference between the superconductors is $ \varphi=\pi$ and their length is larger than the Majorana localization length. While this picture is understood in terms of a Hermitian description of isolated junctions, unavoidable transport conditions due to coupling to reservoirs make them open and ground for non-Hermitian effects that still remain largely unexplored. In this work, we investigate the impact of non-Hermiticity on Josephson junctions hosting four Majorana zero modes when they are coupled to normal leads. We demonstrate that, depending on whether inner or outer Majorana zero modes are subjected to non-Hermiticity, Andreev exceptional points can form between lowest (higher energy) Andreev bound states connected by stable zero real energy lines. We further find that the Andreev exceptional points give rise to strong local and nonlocal spectral weights, thus providing a way for their identification via, e.g., conductance measurements. Our findings unveil non-Hermiticity for designing non-Hermitian topological phases and for operating Andreev bound states in Josephson junctions hosting Majorana zero modes.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 7 figures
Nambu Non-equilibrium Thermodynamics II:Reduction of a complex system to a simple one
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-28 20:00 EDT
So Katagiri, Yoshiki Matsuoka, Akio Sugamoto
Non-equilibrium thermodynamics far from equilibrium is investigated in terms of a generalized ``Nambu dynamics’’ (termed Nambu non-equilibrium thermodynamics (NNET)); NNET consists of Nambu dynamics with multiple Hamiltonians and an entropy causing dissipation.
It is shown that a general complex non-linear non-equilibrium system far from equilibrium can be reduced to a simple NNET, on the basis of an existence proposition of NNET. This proposition is, however, proved only formally, so that there may exist various obstacles to destroy it.
Non-equilibrium thermodynamics studied in this article is quite general, including the case in which the product of dynamical and affinity forces forms a higher-order mixed tensor.
Statistical Mechanics (cond-mat.stat-mech), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph)
21 pages
Fermi polarons with the finite-range fermion-impurity interactions
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-28 20:00 EDT
We study a problem of an infinitely heavy impurity introduced into a polarized Fermi gas, which can be solved exactly with the help of Fumi’s theorem. We consider the regime of finite-range fermion-impurity interactions beyond the standard $ s$ -wave scattering regime and investigate how this affects the energy of the polaron. We show how one can account for the effective range effects as well as the contribution from higher angular momentum channels, which are important for the study of ionic and Rydberg polarons. Our findings have relevance for atomic gas mixtures with a large mass imbalance and for the impurities trapped inside the optical tweezers.
Quantum Gases (cond-mat.quant-gas)
4 pages, 3 figures
Accurate calculation of light rare-earth magnetic anisotropy with density functional theory
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Density functional theory (DFT) has long struggled to treat light rare-earth magnetism. We show that this difficulty arises from an overestimate of the $ 4f$ charge asphericity, and thus the magnetic anisotropy energy, due to the inadequacy of single Slater-determinant representations. We propose an effective solution by combining constrained DFT+U with crystal field theory and a systematic many-body correction to the charge asphericity. We confirm the validity of this combination on TbV$ _6$ Sn$ _6$ and TbCo$ _5$ , and then show how the many-body correction adjusts the calculated magnetic anisotropy energy of SmCo$ _5$ to match experiment. Our method is an efficient DFT-based approach to address light-rare-earth magnetism.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
6 pages, 3 figures
Band gap formation theory: An alternative to the Bragg diffraction model
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Koichi Kajiyama (Tohoku University, NICHe)
The band gap, a key concept in solid-state physics, is traditionally explained by the Bragg diffraction of electron waves in the periodic potential of a crystal. Although widely accepted, this framework raises fundamental issues in one-dimensional systems, where Bragg diffraction-which requires multidirectional wave interactions-reduces to simple interference, thus failing to explain band gap formation. In this paper, we introduce an alternative theory that does not rely on Bragg reflection. Using the Schrödinger equation for Bloch waves, we consider the crystal lattice as a discrete set of observation points. This discreteness introduces a sampling-like constraint analogous to the Nyquist frequency in signal processing. We show that when the electron wavenumber changes under a periodic potential while the lattice spacing remains fixed, a band gap naturally emerges as a sampling effect. By constructing an energy diagram that incorporates this effect, we reveal that the band gap originates from both the wavenumber change and the role of the lattice as discrete samplers, leading the energy curve to exhibit translational and mirror symmetries with respect to the Nyquist wavenumber. This approach provides a novel, physically grounded explanation of band gap formation and can be naturally extended to higher dimensions.
Materials Science (cond-mat.mtrl-sci)
12 pages, 6 figures. Submitted to Physical Review B
Observation of topological switch between Weyl semimetal and third-order topological insulator phases
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Yu-Hong Han, Yi Li, Feng Mei, Liantuan Xiao, Suotang Jia
Weyl semimetals and higher-order topological insulators represent two fundamental yet distinct classes of topological matter. While both have been extensively studied in classical-wave systems, their coexistence and controllable transition within a single platform remain largely unexplored. Meanwhile, implementing three-dimensional spin-orbit couplings, which is crucial for realizing a broad class of higher-dimensional topological phases, continues to pose significant experimental challenges. Here, we experimentally realize three-dimensional spin-orbit couplings and demonstrate that tuning the dimerized spin-orbit coupling strength enables both the coexistence of and a controllable switch between Weyl semimetal and third-order topological insulator phases. By engineering a three-dimensional circuit metamaterial, we synthesize the required spin-orbit interactions and observe hallmark signatures of both phases: frequency spectroscopy reveals the Fermi arcs, while local density of states measurements identify the topological corner modes. Interestingly, the corner mode degeneracy doubles compared to that in the canonical Benalcazar-Bernevig-Hughes model, signaling an enriched topological structure. Our study establishes a fundamental connection between two paradigmatic topological phases and paves the way for further exploring spin-orbit-coupling induced exotic higher-dimensional topological phases.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics)
17 pages, 7 figures,
Half-Quantized Hall Metal and Marginal Metal in Disordered Magnetic Topological Insulators
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-08-28 20:00 EDT
Shi-Hao Bi, Bo Fu, Shun-Qing Shen
A semimagnetic topological insulator – a heterostructure combining a topological insulator with a ferromagnet – exhibits a half-quantized Hall effect, characterized by a quantized Hall conductance of $ \frac{1}{2}\frac{e^{2}}{h}$ (where $ e$ is the elementary charge and $ h$ is the Planck constant), which reinforces the established understanding of topological phenomena in condensed matter physics. However, its stability in realistic, disordered systems remains poorly understood. Here, we demonstrate the robustness of the half-quantized Hall effect in weakly disordered systems, stemming from a single gapless Dirac cone of fermions and coexisting with weak antilocalization due to the $ \pi$ Berry phase that suppresses backscattering. Furthermore, we uncover a marginal metallic phase emerging between weak antilocalization and Anderson insulation – a transition that defies conventional metal-insulator transitions by lacking an isolated critical point – where both conductance and normalized localization length exhibit scale invariance, independent of system size. The half-quantized Hall metal and the marginal metallic phase challenge existing localization theories and provide insights into disorder-driven topological phase transitions in magnetic topological insulators, opening avenues for exploring quantum materials and next-generation electronic devices.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
29 pages, 6 figures
Communications Physics 8, 332 (2025)
Theory of superconductivity and mass enhancement near CDW critical point based on Bethe-Salpeter equation method: application to cuprates
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-28 20:00 EDT
Youichi Yamakawa, Hiroshi Kontani
In recent years, charge-channel orders in strongly correlated metals have attracted great attention. Famous examples are the electronic nematic orders in cuprates and iron-based superconductors, and Star-of-David order in kagome metals. Critical phenomena and unconventional superconductivity arising from fluctuations of such charge-channel orders are central issues today; however, the essential role is played by the vertex corrections, which are the many-body effects that are dropped in conventional mean-field type approximations. To solve this difficulty, in this study, we propose the Bethe-Salpeter equation theory to evaluate electron-electron interactions in two dimensional Hubbard models. This method satisfies the criteria of the Baym-Kadanoff conserving approximation. Here, we find that an attractive interaction in the charge channel emerges from the Aslamazov-Larkin vertex corrections that describe the interference processes among spin fluctuations. Applying this method to the square-lattice Hubbard model, we reveal that the cooperation of attractive charge fluctuations and repulsive spin fluctuations yields high-$ T_c$ $ d$ -wave superconductivity together with enhanced effective mass. These results naturally explain the phase diagram of cuprate superconductors, where strong-coupling $ d$ -wave superconductivity appears near the charge-order quantum critical point. The theory can also be applied to multi-orbital Hubbard models, like iron-based and nickelate superconductors, suggesting broad potential for future applications.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 9 figures
A non-invasive dry-transfer method for fabricating mesoscopic devices on sensitive materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Zhongmou Jia, Yiwen Ma, Zhongchen Xu, Xue Yang, Jianfei Xiao, Jiezhong He, Yunteng Shi, Zhiyuan Zhang, Duolin Wang, Sicheng Zhou, Bingbing Tong, Peiling Li, Ziwei Dou, Xiaohui Song, Guangtong Liu, Jie Shen, Zhaozheng Lyu, Youguo Shi, Jiangping Hu, Li Lu, Fanming Qu
Many materials with novel or exotic properties are highly sensitive to environmental factors such as air, solvents, and heat, which complicates device fabrication and limits their potential applications. Here, we present a universal submicron fabrication method for mesoscopic devices using a dry-transfer technique, tailored specifically for sensitive materials. This approach utilizes PMMA masks, combined with a water-dissoluble coating as a sacrificial layer, to ensure that sensitive materials are processed without exposure to harmful environmental conditions. The entire fabrication process is carried out in a glove box, employing dry techniques that avoid air, solvents, and heat exposure, culminating in an encapsulation step. We demonstrate the utility of this method by fabricating and characterizing K2Cr3As3 and WTe2 devices, a one- and two-dimensional material, respectively. The results show that our technique preserves the integrity of the materials, provides excellent contact interfaces, and is broadly applicable to a range of sensitive materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Appl. Phys. Lett. 126, 243504 (2025)
Giant Anomalous Hall Conductivity and Gilbert Damping in Room-temperature Ferromagnetic Half-Heusler Alloys PtMnBi
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Hong-Xue Jiang, Jia-wan Li, Shi-Bo Zhao, Jie Wang, Yusheng Hou
Half-Heusler alloys have emerged as promising candidates for novel spintronic applications due to their exceptional properties including the high Curie temperature (TC) above room temperature and large anomalous Hall conductivity (AHC). In this work, we systematically study the magnetic and electronic properties of PtMnBi in {\alpha}-, {beta}-, and {\gamma}-phase using first-principles calculations and Monte Carlo simulations. The three phases are found to be ferromagnetic metals. In particular, the {\alpha}-phase PtMnBi shows a high TC up to 802 K and a relatively large Gilbert damping of 0.085. Additionally, the {\gamma}-phase PtMnBi possesses a non-negligible AHC, reaching 203 {\Omega}-1cm-1 at the Fermi level. To evaluate its potential in nanoscale devices, we further investigate the {\alpha}-phase PtMnBi thin films. The Gilbert dampings of {\alpha}-phase PtMnBi thin films varies with film thickness and we attribute this variation to the distinct band structures at the high-symmetry point {\Gamma}, which arise from differences in film thickness. Moreover, the 1-layer (1L) {\alpha}-phase thin film retains robust ferromagnetism (TC = 688 K) and shows enhanced Gilbert damping (0.14) and AHC (1116 {\Omega}-1cm-1) compared to the bulk. Intriguingly, under a 2% in-plane biaxial compressive strain, the Gilbert damping of 1L {\alpha}-phase PtMnBi thin film increases to 0.17 and the AHC reaches 2386 {\Omega}-1cm-1. The coexistence of giant Gilbert damping and large AHC makes {\alpha}-phase PtMnBi a compelling platform for practical spintronic applications, and highlights the potential of half-Heusler alloys in spintronic device design.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
16 pages, 5 figures, accepted by Frontiers of Physics
Multiband Superconductivity and High Critical Current Density in Entropy Stabilized Nb0.25Ta0.25Ti0.25Zr0.25
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-28 20:00 EDT
Nikita Sharma, Kuldeep Kargeti, Neha Sharma, Pooja Chourasia, B. Vignolle, Olivier Toulemonde, Tirthankar Chakraborty, S. K. Panda, Sourav Marik
High and medium-entropy superconductors with significant intrinsic disorder are a fascinating class of superconductors. Their combination of robust structural integrity, superior mechanical properties, and exceptional irradiation tolerance makes them promising candidates for use in advanced superconducting technologies. Herein, we present a comprehensive theoretical and experimental investigation on the superconductivity of equiatomic entropy-stabilized Nb0.25Ta0.25Ti0.25Zr0.25. The material shows bulk superconductivity (transition temperature = 8K) with a high upper critical field of 11.94T. Interestingly, both the electronic band structure and specific heat data point toward unconventional multiband superconductivity. Our ab initio calculations reveal Dirac-like band crossings close to the Fermi level, with certain degeneracies persisting even in the presence of spin-orbit coupling, suggesting a possible interplay between topological electronic states and the observed unconventional superconductivity. Remarkably, the critical current density exceeds the benchmark of 10^5 A/cm2, surpassing all previously reported as-cast entropy-stabilized superconductors. This high critical current density is likely attributed to strong flux pinning at the grain boundaries, facilitated by extreme intrinsic lattice distortion. Taken together, the demonstrated dynamical stability, excellent metallicity, potential to host unconventional superconductivity, and exceptionally high critical current density highlight the potential of entropy-stabilized alloys as a platform for exploring the confluence of disorder, topology, and unconventional superconductivity.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 8 figures
Intrinsic nonlinear valley Nernst effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Xue-Jin Zhang, Jin Cao, Lulu Xiong, Hui Wang, Shen Lai, Cong Xiao, Shengyuan A. Yang
We investigate the intrinsic nonlinear valley Nernst effect, which induces a transverse valley current via a second-order thermoelectric response to a longitudinal temperature gradient. The effect arises from the Berry connection polarizability dipole of valley electrons and is permissible in both inversion-symmetric and inversion-asymmetric materials. We demonstrate that the response tensor is connected to the intrinsic nonlinear valley Hall conductivity through a generalized Mott relation, with the two being directly proportional at low temperatures, scaled by the Lorenz number. We elucidate the symmetry constraints governing this effect and develop a theory for its nonlocal measurement, revealing a nonlocal second-harmonic signal with a distinct $ \rho^2$ scaling. This signal comprises two scaling terms, with their ratio corresponding to the square of the thermopower normalized by the Lorenz number. Key characteristics are demonstrated using a tilted Dirac model and first-principles calculations on bilayer WTe$ _2$ . Possible extrinsic contributions and alternative experimental detection methods, e.g., by valley pumping and by nonreciprocal directional dichroism, are discussed. These findings underscore the significance of band quantum geometry on electron dynamics and establish a theoretical foundation for nonlinear valley caloritronics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Optical Switching of Moiré Chern Ferromagnet
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Xiangbin Cai, Haiyang Pan, Yuzhu Wang, Abdullah Rasmita, Shunshun Yang, Yan Zhao, Wei Wang, Ruihuan Duan, Ruihua He, Kenji Watanabe, Takashi Taniguchi, Zheng Liu, Jesús Zúñiga Pérez, Bo Yang, Weibo Gao
Optical manipulation of quantum matter offers a non-contact, high-precision and fast control. Fractional Chern ferromagnet states in moiré superlattices are promising for topological quantum computing, but an effective optical control protocol has remained elusive. Here, we demonstrate robust optical switching of integer and fractional Chern ferromagnets in twisted MoTe2 bilayers using circularly polarized light. Highly efficient optical manipulation of spin orientations in the topological ferromagnet regime is realized at zero field using a pump light power as low as 28 nanowatts per square micrometer. Utilizing this optically induced transition, we also demonstrate magnetic bistate cycling and spatially resolved writing of ferromagnetic domain walls. This work establishes a reliable and efficient optical control scheme for moiré Chern ferromagnets, paving the way for dissipationless spintronics and quantized Chern junction devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
4 figures
A phenomenological universal expression for the condensate fraction in strongly-correlated two-dimensional Bose gases
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-28 20:00 EDT
G.E. Astrakharchik, I.L. Kurbakov, N.A. Asriyan, Yu. E. Lozovik
We investigate the relation between non-local and energetic properties in 2D quantum systems of zero-temperature bosons. By analyzing numerous interaction potentials across densities spanning from perturbative to strongly correlated regime, we discover a novel high-precision quantum phenomenological universality: the condensate fraction can be expressed through kinetic energy and quantum energy, defined as total energy relative to classical crystal state. Quantum Monte Carlo simulations accurately validate our analytical expression. Furthermore, we test the obtained relation on the fundamental example of a non-perturbative system, namely, the liquid helium. The proposed relation is relevant to experiments with excitons in transition metal dichalcogenides (TMDC) materials, as well as ultracold atoms and other quantum systems in reduced dimensionality.
Quantum Gases (cond-mat.quant-gas)
24 pages, 7 figures
Multi-value Probabilistic Computing with current-controlled Skyrmion Diffusion
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Thomas B. Winkler, Yuean Zhou, Grischa Beneke, Fabian Kammerbauer, Sachin Krishnia, Mario Carpentieri, Davi R. Rodrigues, Mathias Kläui, Johan H. Mentink
Magnetic systems are highly promising for implementing probabilistic computing paradigms because of the fitting energy scales and conspicuous non-linearities. While conventional binary probabilistic computing has been realized, implementing more advantageous multi-value probabilistic computing (MPC) remains a challenge. Here, we report the realization of MPC by leveraging the thermally activated diffusion of magnetic skyrmions through an effectively non-flat energy landscape defined by a discrete number of pinning sites. The time-averaged spatial distribution of the diffusing skyrmions directly realizes a discrete probability distribution, which is tunable by current-generated spin-orbit torques, and can be quantified by non-perturbative electrical measurements. Even a very straightforward implementation with global tuning, already allows us to demonstrate the softmax computation - a core function in artificial intelligence. As a key advance, we demonstrate invertible logic without the need to create a network of probabilistic devices, offering major scalability advantages. Our proof of concept can be generalized to multiple skyrmions and can accommodate multiple locally tunable inputs and outputs using magnetic tunnel junctions, potentially enabling the representation of highly complex distribution functions.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)
38 pages, 7 figures, 2 tables
Inverse Elastica: A Theoretical Framework for Inverse Design of Morphing Slender Structures
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-28 20:00 EDT
JiaHao Li, Weicheng Huang, YinBo Zhu, Luxia Yu, Xiaohao Sun, Mingchao Liu, HengAn Wu
Inverse design of morphing slender structures with programmable curvature has significant applications in various engineering fields. Most existing studies formulate it as an optimization problem, which requires repeatedly solving the forward equations to identify optimal designs. Such methods, however, are computationally intensive and often susceptible to local minima issues. In contrast, solving the inverse problem theoretically, which can bypass the need for optimizations, is highly efficient yet remains challenging, particularly for cases involving arbitrary boundary conditions (BCs). Here, we develop a systematic theoretical framework, termed inverse elastica, for the direct determination of the undeformed configuration from a target deformed shape along with prescribed BCs. Building upon the classical elastica, inverse elastica is derived by supplementing the geometric equations of undeformed configurations. The framework shows three key features: reduced nonlinearity, solution multiplicity, and inverse loading. These principles are demonstrated through two representative models: an analytical solution for a two-dimensional arc and a numerical continuation study of the inverse loading of a three-dimensional helical spring. Furthermore, we develop a theory-assisted optimization strategy for cases in which the constrains of the undeformed configurations cannot be directly formulated as BCs. Using this strategy, we achieve rational inverse design of complex spatial curves and curve-discretized surfaces with varying Gaussian curvatures. Our theoretical predictions are validated through both discrete elastic rod simulations and experiments.
Soft Condensed Matter (cond-mat.soft)
29 pages, 11 figures
Atomistic insights into hydrogen migration in IGZO from machine-learning interatomic potential: linking atomic diffusion to device performance
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Hyunsung Cho, Minseok Moon, Jaehoon Kim, Eunkyung Koh, Hyeon-Deuk Kim, Rokyeon Kim, Gyehyun Park, Seungwu Han, Youngho Kang
Understanding hydrogen diffusion is critical for improving the reliability and performance of oxide thin-film transistors (TFTs), where hydrogen plays a key role in carrier modulation and bias instability. In this work, we investigate hydrogen diffusion in amorphous IGZO ($ a$ -IGZO) and $ c$ -axis aligned crystalline IGZO (CAAC-IGZO) using machine learning interatomic potential molecular dynamics (MLIP-MD) simulations. We construct accurate phase-specific MLIPs by fine-tuning SevenNet-0, a universal pretrained MLIP, and validate the models against a comprehensive dataset covering hydrogen-related configurations and diffusion environments. Hydrogen diffusivity is evaluated over 650–1700 K, revealing enhanced mobility above 750 K in $ a$ -IGZO due to the glassy matrix, while diffusion at lower temperatures is constrained by the rigid network. Arrhenius extrapolation of the diffusivity indicates that hydrogen in $ a$ -IGZO can reach the channel/insulator interface within $ 10^{4}$ seconds at 300–400 K, likely contributing to negative bias stress-induced device degradation. Trajectory analysis reveals that long-range diffusion in $ a$ -IGZO is enabled by a combination of hydrogen hopping and flipping mechanisms. In CAAC-IGZO, hydrogen exhibits high in-plane diffusivity but severely restricted out-of-plane transport due to a high energy barrier along the $ c$ -axis. This limited vertical diffusion in CAAC-IGZO suggests minimal impact on bias instability. This work bridges the atomic-level hydrogen transport mechanism and device-level performance in oxide TFTs by leveraging large-scale MLIP-MD simulations.
Materials Science (cond-mat.mtrl-sci)
13 pages, 9 figures, Supplementary information included as ancillary file (+15 pages)
Ultrafast Spin Accumulations Drive Magnetization Reversal in Multilayers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Harjinder Singh, Alberto Anadón, Junta Igarashi, Quentin Remy, Stéphane Mangin, Michel Hehn, Jon Gorchon, Gregory Malinowski
Engineering and controlling heat and spin transport on the femtosecond time-scale in spintronic devices opens up new ways to manipulate magnetization with unprecedented speed. Yet the underlying reversal mechanisms remain poorly understood due to the challenges of probing ultrafast, non-equilibrium spin dynamics. In this study, we demonstrate that typical magneto-optical experiments can be leveraged to access the time evolution of the spin accumulation generated within a magnetic multilayer following an ultrafast laser excitation. Furthermore, our analysis shows that the final magnetic state of the free-layer in a spin-valve is mainly dictated by the ultrafast dynamics of the reference-layer magnetization. Our results disentangle magnetization and spin transport dynamics within a multilayer stack and identify demagnetization and remagnetization-driven spin accumulation as the key mechanism for all-optical switching. These findings establish new design principles for ultrafast spintronic devices based on tailored spin current engineering.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
6 pages, 4 figures
MnBr$_2$ on the graphene on Ir(110) substrate: growth, structure, and super-moiré
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Affan Safeer, Oktay Güleryüz, Nicolae Atodiresei, Wouter Jolie, Thomas Michely, Jeison Fischer
Single-layer MnBr$ _2$ is grown on graphene (Gr) supported by Ir(110) and investigated using low-energy electron diffraction, scanning tunneling microscopy, and spectroscopy. The structure and epitaxial relationship with the substrate are systematically characterized. The growth morphology strongly depends on the growth temperature, evolving from fractal to dendritic and eventually to compact dendritic skeletal islands, reflecting changes in the underlying surface diffusion processes. MnBr$ _2$ on Gr/Ir(110) constitutes a three-lattice system, giving rise to a super-moiré pattern –a moiré of moirés. Due to the involvement of lattices of differing symmetries and the partial electronic transparency of Gr, a “virtual” moiré formed by MnBr$ _2$ and Ir(110) contributes to the super-moiré formation. Ab initio calculations play a crucial role in understanding the complexity of super-moiré. Moreover, the pronounced variation in the apparent height with tunneling conditions for the magnetic insulator is explained based on the measured electronic structure.
Materials Science (cond-mat.mtrl-sci)
24 pages, 7 figures
Kinetic pathways of coesite densification from metadynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
We study compression of coesite to pressures above 35 GPa, substantially beyond the equilibrium transition pressure to octahedral phases (8 GPa to stishovite). Experiments at room temperature showed that up to 30 GPa the metastable coesite structure develops only minor displacive changes (coesite-II and coesite-III) while the Si atoms remain 4-coordinated. Beyond 30 GPa, reconstructive transformations start, following different pathways from the complex structure of coesite. Besides amorphization, two different crystalline outcomes were observed. One is formation of defective high-pressure octahedral phases (Hu et al., 2015) and another one is formation of unusual and complex dense phases coesite-IV and coesite-V with Si atoms in 4-fold, 5-fold and 6-fold coordination (Bykova et al., 2018). Capturing these structural transformations computationally represents a challenge. Here we show that employing metadynamics with Si-O coordination number and volume as generic collective variables in combination with a machine-learning based ACE potential (Erhard et al., 2024), one naturally observes all three mentioned pathways, resulting in the phases observed experimentally. We describe the atomistic mechanisms along the transformation pathways. While the pathway to coesite-IV is simpler, the transformation to octahedral phases involves two steps: first, a hcp sublattice of O atoms is formed where Si atoms occupy octahedral positions but the octahedra chains do not form a regular pattern. In the second step, the Si atoms order and the chains develop a more regular arrangement. We predict that the pathway to coesite-IV is preferred at room temperature, while at 600 K the formation of octahedral phases is more likely.
Materials Science (cond-mat.mtrl-sci), Statistical Mechanics (cond-mat.stat-mech)
8 pages and 9 figures. For the Supplemental Material, please look into the source .zip archive. The following article has been accepted by The Journal of Chemical Physics. After it is published, it will be found at this https URL
Charge current and phase diagram of the disordered open longer-range Kitaev chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-28 20:00 EDT
Emmanuele G. Cinnirella, Andrea Nava, Domenico Giuliano
We compute the disorder averaged dc conductance in the non-equilibrium steady state that sets in between a longer-range Kitaev chain and a metallic lead connected to an external reservoir, as a function of the system parameters and of the disorder strength. From our results, we map out the phase diagram of the disordered chain for different types of disorder and discuss the corresponding effects of the interplay between topology and disorder in the system. To do so, we set up a combined analytical and numerical approach, which is potentially amenable of straightforward generalizations to other disordered topological systems.
Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 9 figures
Majorana Diagrammatics for Quantum Spin-1/2 Models
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-28 20:00 EDT
Thibault Noblet, Laura Messio, Riccardo Rossi
A diagrammatic formalism for lattices of 1/2 is developed. It is based on an unconstrained mapping between spin and Majorana operators. This allows the use of standard tools of diagrammatic quantum many-body theory without requiring projections. We derive, in particular, the Feynman rules for the expansion around a color-preserving mean-field theory. We then present the numerical results obtained by computing the corrections up to second order for the Heisenberg model in one and two dimensions, showing that perturbative corrections are not only numerically important, but also qualitatively improve the results of mean-field theory. These results pave the way for the use of Majorana diagrammatic tools in theoretical and numerical studies of quantum spin systems.
Strongly Correlated Electrons (cond-mat.str-el)
29 pages, 10 figures
Search for thermodynamically stable ambient-pressure superconducting hydrides in GNoME database
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-28 20:00 EDT
Antonio Sanna, Tiago F. T. Cerqueira, Ekin Dogus Cubuk, Ion Errea, Yue-Wen Fang
Hydrides are considered to be one of the most promising families of compounds for achieving high temperature superconductivity. However, there are very few experimental reports of ambient-pressure hydride superconductivity, and the superconducting critical temperatures ($ T_{\rm c}$ ) are typically less than 10 K. At the same time several hydrides have been predicted to exhibit superconductivity around 100 K at ambient pressure but in thermodynamically unfavorable phases. In this work we aim at assessing the superconducting properties of thermodynamically stable hydride superconductors at room pressure by investigating the GNoME material database, which has been recently released and includes thousands of thermodynamically stable hydrides. To scan this large material space we have adopted a multi stage approach which combines machine learning for a fast initial evaluation and cutting edge ab initio methods to obtain a reliable estimation of $ T_{\rm c}$ . Ultimately we have identified 22 cubic thermodynamically stable hydrides with $ T_{\rm c}$ above 4.2 K and reach a maximum $ T_{\rm c}$ of 17 K. While these critical temperatures are modest in comparison to some recent predictions, the systems where they are found, being stable, are likely to be experimentally accessible and of potential technological relevance.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
10 pages, 5 figures in main text
Regularized Micromagnetic Theory for Bloch Points
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Vladyslav M. Kuchkin, Andreas Haller, Andreas Michels, Thomas L. Schmidt, Nikolai S. Kiselev
Magnetic singularities known as Bloch points (BPs) present a fundamental challenge for micromagnetic theory, which is based on the assumption of a fixed magnetization vector length. Due to the divergence of the effective field at a BP, classical micromagnetics fails to adequately describe BP dynamics. To address this issue, we propose a regularized micromagnetic model in which the magnetization vector can vary in length but not exceed a threshold value. More specifically, the magnetization is treated as an order parameter constrained to a S3-sphere. This constraint respects fundamental properties of local spin expectation values in quantum systems. We derive the corresponding regularized Landau-Lifshitz-Gilbert equation and the analogue of the Thiele equation describing the steady motion of spin textures under various external stimuli. We demonstrate the applicability of our theory by modeling the dynamics of several magnetic textures containing BPs, including domain walls in nanowires, chiral bobbers, and magnetic dipolar strings. The presented results extend micromagnetic theory by incorporating a regularized description of BP dynamics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
18 pages, 4 figures
Emissive perovskite quantum wires in robust nanocontainers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Bea Botka, Erzsébet Dodony, Ildikó Harsányi, Michael Stratton, János Mózer, Éva Kováts, Katalin Kamarás
Light emissive nanostructures were prepared from boron nitride nanotubes (BNNTs) filled with inorganic lead halide perovskites. BNNTs provide a platform for facile synthesis of high aspect ratio perovskite quantum wires having color-tunable, highly polarized emission. BNNTs form a flexible and robust protective shell around individual nanowires, that mitigate degradation during post-processing for practical applications, while allowing to exploit the emission of the perovskite nanowires due to its optical transparency. The wire diameter can be tuned by choosing appropriate BNNT hosts, giving easy access to the strongly quantum confined diameter range. The individual encapsulated quantum wires can be used as building blocks for nanoscale photonic devices, and to create large-scale flexible assemblies.
Materials Science (cond-mat.mtrl-sci)
Exotic rheology of materials with active rearrangements
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-28 20:00 EDT
Aondoyima Ioratim-Uba, Tanniemola B. Liverpool, Silke Henkes
The flow of biological tissues during development is controlled through the active stresses generated by cells interacting with their mechanical environment in the tissue. Many developmental processes are driven by convergence-extension flows where the tissue has an emergent negative shear modulus and viscosity. This exotic rheology is generated through active T1 transitions where rearrangements are opposite the applied stress direction. Here, we introduce a mean-field elasto-plastic model which shows convergence-extension, based on the Hebraud-Lequeux model, that includes both passive and active elastic elements with opposite stress responses. We find that the introduction of active elements profoundly changes the rheology. Beyond a threshold fraction of active elements, it gives rise to non-monotonic flow curves and negative stresses at positive strain rates. Controlled by the active fraction and the stress diffusion rate, we find both yield stress materials and fluids, with either a positive or negative yield stress or viscosity. These features are characteristic of metamaterials, and highlight how biology uses disordered, active materials with exotic rheology.
Soft Condensed Matter (cond-mat.soft)
5 pages, 3 figures
Tunable quantum anomalous Hall effect in fullerene monolayers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Leonard Werner Pingen, Jiaqi Wu, Bo Peng
Nearly four decades after its theoretical prediction, the search for material realizations of quantum anomalous Hall effect (QAHE) remains a highly active field of research. Many materials have been predicted to exhibit quantum anomalous Hall (QAH) physics under feasible conditions but the experimental verification remains widely elusive. In this work, we propose an alternative approach towards QAH materials design by engineering customized molecular building blocks. We demonstrate this ansatz for a two-dimensional (2D) honeycomb lattice of C26 fullerenes, which exhibits a ferromagnetic ground state and thus breaks time-reversal symmetry. The molecular system is found to be highly tunable with respect to its magnetic degrees of freedom and applied strain, giving rise to a rich phase diagram with Chern numbers C= +/-2, +/-1, 0. Our proposal offers a versatile platform to realize tunable QAH physics under accessible conditions and provides an experimentally feasible approach for chemical synthesis of molecular networks with QAHE.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)
LEMONS: An open-source platform to generate non-circuLar, anthropometry-based pEdestrian shapes and simulate their Mechanical interactiONS in two dimensions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-28 20:00 EDT
Oscar Dufour (ILM, CNRS), Alexandre Nicolas (ILM, CNRS), Maxime Stapelle (ILM, CNRS)
We offer a collection of videos showing simulations of pedestrian crowds made with the LEMONS software. LEMONS is an open-source computational tool designed for modelling dense crowds. The platform features an intuitive online interface, enabling users to generate 2D and 3D pedestrian crowds based on anthropometric data. Additionally, it features a C++ library that computes mechanical contacts with other agents and obstacles, and evolves the crowd’s configuration. Both the online platform and the library can readily be called from Python scripts, providing users with complete flexibility to implement their own decision-making models, such as specifying the desired velocities of individuals within the crowd.__Documentation is also provided.
Soft Condensed Matter (cond-mat.soft), Computational Physics (physics.comp-ph), Physics and Society (physics.soc-ph)
Microscale optoelectronic reservoir networks of halide perovskite for in-sensor computing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Jeroen J. de Boer, Agustin O. Alvarez, Moritz C. Schmidt, Bruno Ehrler
Physical reservoir computing is a promising framework for efficient neuromorphic in and near-sensor computing applications. Here, we demonstrate a multimodal optoelectronic reservoir network based on halide perovskite semiconductor devices, capable of processing both voltage and light inputs. The devices consist of micrometer-sized, asymmetric crossbars covered with a MAPbI3 perovskite film. In a network, we simulate the performance by transforming MNIST images and videos based on the NMNIST dataset using 4-bit inputs and training linear readout layers for classification. We demonstrate multimodal networks capable of processing both voltage and light inputs, reaching mean accuracies up to 95.3 p/m 0.1% and 87.8 p/m 0.1% for image and video classification, respectively. We observed only minor deterioration due to measurement noise. The networks significantly outperformed linear classifier references, by 3.1% for images and 14.6% for video. We show that longer retention times benefit classification accuracy for single-mode networks, and give guidelines for choosing optimal experimental parameters. Moreover, the microscale device architecture lends itself well to further downscaling in high-density sensor arrays, making the devices ideal for efficient in-sensor computing.
Materials Science (cond-mat.mtrl-sci)
Multi-origin driven giant planar Hall effect in topological antiferromagnet EuAl2Si2 with tunable spin texture
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-28 20:00 EDT
Xiangqi Liu, Ziyi Zhu, Yixuan Luo, Zhengyang Li, Bo Bai, Jingcheng Huang, Xia Wang, Chuanying Xi, Li Pi, Guanxiang Du, Leiming Chen, Wenbo Wang, Wei Xia, Yanfeng Guo
In topological materials, the planar Hall effect (PHE) is often regarded as a hallmark of profound quantum phenomena-most notably the Adler-Bell-Jackiw chiral anomaly and Berry curvature-rendering it an indispensable tool for deciphering the topological essence of emergent phases. In this study, we delve into the PHE and anisotropic magnetoresistance in the recently discovered layered topological antiferromagnet EuAl2Si2. Our analysis of the robust PHE signal (~3.8 {\mu}{\Omega} cm at 2 K and 8 T) unveils a distinct interplay of mechanisms. While Berry curvature plays a minor role, the dominant contributions stem from classical orbital MR in the field-induced ferromagnetic state and field-suppressed spin fluctuations in the paramagnetic regime. These insights not only position EuAl2Si2-with its highly tunable spin texture-as an exemplary system for probing the intricate coupling between spin configurations and band topology in magnetotransport but also pave the way for designing novel materials with tailored PHE responses, highlighting significant application prospects in quantum sensing, spintronic devices, and topologically protected electronic systems.
Strongly Correlated Electrons (cond-mat.str-el)
17 pages and 5 figures
Decoupling dynamics and crosslink stability in supramolecular hydrogels using associative exchange
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-28 20:00 EDT
Pierre Le Bourdonnec, Charafeddine Ferkous, Leo Communal, Luca Cipelletti, Rémi Merindol
The design of hydrogels that combine mechanical robustness with dynamic reconfigurability remains a fundamental challenge, as increasing crosslink dissociation rates compromise network integrity. This limitation is addressed through the incorporation of an associative crosslink exchange into DNA-based supramolecular hydrogels, enabling the decoupling of network relaxation behavior from crosslink stability. The hydrogels are constructed from enzyme-synthesized single-stranded DNA that self-assembles via hybridization between complementary domains. These crosslinks can reorganize through dissociative melting or associative strand displacement reaction, yielding networks with tunable relaxation timescales spanning over three orders of magnitude. Rheological measurements and thermodynamic modeling confirm that associative exchange facilitates efficient stress dissipation without diminishing rupture strength or thermal stability. In contrast, dissociative systems inherently trade increased dynamics with mechanical weakening. This decoupling is achieved through the implementation of a catalytic reorganization pathway governed by the composition of the sample, independently of crosslink strength. These findings establish the mechanism of reorganization as a key design parameter for engineering adaptive soft materials that combine resilience and responsiveness.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
47 pages, 13 Figures
Nanoscale mechanics and ultralow Friction of natural 2D silicates: Biotite and Rhodonite
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Surbhi Slathia, Manoj Tripathi, Raphael Benjamim de Oliveira, Guilherme da Silva Lopes Fabris, Bruno Ipaves, Raphael Matozo Tromer, Marcelo Lopes Pereira Junior, Gelu Costin, Preeti Lata Mahapatraa, Nicholas R. Glavin, Ajit K. Roy, Venkataramana Gadhamshetty, Douglas Soares Galvao, Alan Dalton, Chandra Sekhar Tiwary
Two-dimensional (2D) silicates have emerged as a promising class of ultrathin materials, expanding the landscape of 2D systems beyond conventional van der Waals crystals. Their unique crystal chemistries and structural anisotropies make them attractive for applications ranging from sensors and flexoelectric devices to drug delivery and catalysis. To unlock their full potential, it is critical to understand their thickness-dependent mechanical properties within the family of 2D silicates. In this study, we investigate the nanomechanical and frictional behaviors of two structurally distinct natural silicates: layered Biotite and chain-structured Rhodonite. Using atomic force microscopy (AFM), we found that Rhodonite exhibits nearly ten times higher adhesion force and modulus response compared to Biotite. Despite this, Biotite demonstrates superior frictional performance, with ultrathin (5 nm) flakes showing a remarkably low coefficient of friction ($ \sim 0.6 \times 10^{-3}$ ) versus Rhodonite ($ \sim 3.6 \times 10^{-3}$ ). To further elucidate interlayer adhesion, density functional theory (DFT) calculations with Hubbard correction were employed. These findings offer valuable insights into the design and selection of 2D silicates for advanced mechanical and tribological applications.
Materials Science (cond-mat.mtrl-sci)
Unlocking Doping Effects on Altermagnetism in MnTe
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-28 20:00 EDT
Nayana Devaraj, Anumita Bose, Arindom Das, Md Afsar Reja, Arijit Mandal, Awadhesh Narayan, B. R. K. Nanda
Governed by specific symmetries, altermagnetism is an emerging field in condensed matter physics, characterized by unique spin-splitting of the bands in the momentum space co-existing with the compensated magnetization as in antiferromagnets. As crystals can have tailored and unintended defects, it is important to gain insights on how altermagnets are affected by the defects-driven symmetry-breaking which, in turn, can build promising perspectives on potential applications. In this study, considering the widely investigated MnTe as a prototype altermagnet, defects are introduced through substitutional doping to create a large configuration space of spin space groups. With the aid of density functional theory calculations, symmetry analysis, and model studies in this configuration space, we demonstrate the generic presence of spin-split of the antiferromagnetic bands in the momentum space. This is indicative of a wider class of quasi-altermagnetic materials, augmenting the set of ideal altermagnetic systems. Furthermore, we show that while pristine MnTe does not show anomalous Hall conductivity (AHC) with out-of-plane magnetization, suitable doping can be carried out to obtain finite and varied AHC. Our predictions of quasi-altermagnetism and doping driven tailored AHC have the potential to open up as-yet-unexplored directions in this developing field.
Materials Science (cond-mat.mtrl-sci)
13 pages, 8 figures, and 1 table
Excitonic skin effect
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-28 20:00 EDT
We show that strong interactions combined with band-dependent imaginary vector potentials give rise to boundary localization of particle-hole pairs, which we term the excitonic skin effect. In a bilayer system with layer-specific gain/loss and an in-plane magnetic field, excitons experience a net imaginary vector potential, resulting in directional amplification of particle-hole pairs. Including nearest-neighbor interactions leads to a non-Hermitian bosonic Kitaev model, where the pairing effects grow exponentially with the size of the system, revealing a unique form of critical skin effect in interacting systems. Our framework applies to both atomic and electronic platforms and is directly testable in current experiments. These results also provide a route to explore non-Hermitian analogs of tensor gauge fields.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
Tunable multi-magnon Floquet topological edge states
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-28 20:00 EDT
Ivan Martinez-Berumen, W. A. Coish, T. Pereg-Barnea
We show that periodically time-modulating the Dzyaloshinskii-Moriya interaction (DMI) in a two-dimensional magnon insulator may induce a topological phase transition that results in the presence of robust edge modes. To this end, we study a square lattice of spins interacting via an XXZ Heisenberg model with a ferromagnetic longitudinal coupling and antiferromagnetic transverse coupling, as well as the aforementioned time-modulated DMI. The topologically protected edge states of this system are composed of coherent superpositions of single-magnon excitations and two magnon bound states. Furthermore, we show that the chirality of the edge states can be controlled by adjusting the relative phase for the drive on the DMI associated with nearest neighbors in the x and y directions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other)
13 pages, 7 figures
Correlated decoherence and thermometry with mobile impurities in a 1D Fermi gas
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-28 20:00 EDT
Sindre Brattegard, Thomás Fogarty, Thomas Busch, Mark T. Mitchison
We theoretically investigate the correlated decoherence dynamics of two mobile impurities trapped within a gas of ultracold fermionic atoms. We use a mean-field approximation to self-consistently describe the effect of impurity-gas collisions on impurity motion, while decoherence of the impurities’ internal state is computed exactly within a functional determinant approach. At equilibrium, we find that the impurities undergo bath-induced localisation as the impurity-gas interaction strength is increased. We then study the non-equilibrium dynamics induced by a sudden change of the impurities’ internal state, which can be experimentally probed by Ramsey interferometry. Our theoretical approach allows us to investigate the effect of impurity motion on decoherence dynamics, finding strong deviations from the universal behaviour associated with Anderson’s orthogonality catastrophe when the mass imbalance between impurity and gas atoms is small. Finally, we show that mobile impurities can be used as thermometers of their environment and that bath-mediated correlations can be beneficial for thermometric performance at low temperatures, even in the presence of non-trivial impurity motion. Our results showcase the interesting open quantum dynamics of mobile impurities dephasing in a common environment, and could help provide more precise temperature estimates of ultracold fermionic mixtures.
Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
14 pages, 11 figures, comments are welcome
Wave coarsening drives time crystallization in active solids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-28 20:00 EDT
Jonas Veenstra, Jack Binysh, Vito Seinen, Rutger Naber, Damien Robledo-Poisson, Andres Hunt, Wim van Saarloos, Anton Souslov, Corentin Coulais
When metals are magnetized, emulsions phase separate, or galaxies cluster, domain walls and patterns form and irremediably coarsen over time. Such coarsening is universally driven by diffusive relaxation toward equilibrium. Here, we discover an inertial counterpart - wave coarsening - in active elastic media, where vibrations emerge and spontaneously grow in wavelength, period, and amplitude, before a globally synchronized state called a time crystal forms. We observe wave coarsening in one- and two-dimensional solids and capture its dynamical scaling. We further arrest the process by breaking momentum conservation and reveal a far-from-equilibrium nonlinear analogue to chiral topological edge modes. Our work unveils the crucial role of symmetries in the formation of time crystals and opens avenues for the control of nonlinear vibrations in active materials.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Adaptation and Self-Organizing Systems (nlin.AO), Pattern Formation and Solitons (nlin.PS)
8 pages, 4 figures and appendix
Anomalous tensorial properties of anisotropic 2D materials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-28 20:00 EDT
Elizabeth J. Dresselhaus, Sanjay Govindjee, Kranthi K. Mandadapu
Odd transport phenomena – defined as a flux response orthogonal to an applied gradient – have been recently observed in isotropic systems, with a multitude of proposed models and experiments to study these effects. Odd transport manifests in tensors that describe linear relations between fluxes and gradients that drive them, particularly when parity and time-reversal symmetries are broken. In this work, we identify such odd properties to be a subset of a broader class of major-symmetry-breaking behaviors, which we term ``anomalous.” We develop a classification of anomalous properties described by $ 2^\mathrm{nd}$ and $ 4^\mathrm{th}$ order tensors in anisotropic 2D materials that maintain discrete rotational and reflection symmetries, characterized by the 17 wallpaper groups. To this end, we present representation theorems for these tensors, identifying which components are constrained for specific spatial symmetries and thereby allowing materials to be grouped into classes that exhibit anomalous responses or not. We focus our discussion on $ 2^\mathrm{nd}$ order tensors in the context of electrical resistivity and on $ 4^\mathrm{th}$ order tensors in the context of viscosity and elasticity. These findings are broadly applicable to the study of novel emergent material properties. To illustrate this, we discuss implications of our findings for two very different 2D materials that have recently garnered attention in condensed matter physics: knitted fabrics and twisted bilayer graphene.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Phase transition properties via partition function zeros: The Blume-Capel ferromagnet revisited
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-28 20:00 EDT
Leïla Moueddene, Nikolaos G Fytas, Bertrand Berche
Since the landmark work of Lee and Yang, locating the zeros of the partition function in the complex magnetic-field plane has become a powerful method for studying phase transitions. Fisher later extended this approach to complex temperatures, and subsequent generalizations introduced other control parameters, such as the crystal field. In previous works [Moueddene et al, J. Stat. Mech. (2024) 023206; Phys. Rev. E 110, 064144 (2024)] we applied this framework to the two- and three-dimensional Blume-Capel model – a system with a rich phase structure where a second-order critical line meets a first-order line at a tricritical point. We showed that the scaling of Lee-Yang, Fisher, and crystal-field zeros yields accurate critical exponents even for modest lattice sizes. In the present study, we extend this analysis and demonstrate that simulations need not be performed exactly at the nominal transition point to obtain reliable exponent estimates. Strikingly, small system sizes are sufficient, which not only improves methodological efficiency but also advances the broader goal of reducing the carbon footprint of large-scale computational studies.
Statistical Mechanics (cond-mat.stat-mech)
23 pages, 18 figures, 1 table, preprint submitted to JSTAT