CMP Journal 2025-07-10
Statistics
Nature: 1
Nature Nanotechnology: 1
Nature Physics: 1
Science: 17
Physical Review Letters: 7
Physical Review X: 2
arXiv: 54
Nature
Extreme river flood exposes latent erosion risk
Original Paper | Environmental impact | 2025-07-09 20:00 EDT
H. J. Barneveld, R. M. Frings, E. Mosselman, J. G. Venditti, M. G. Kleinhans, A. Blom, R. M. J. Schielen, W. H. J. Toonen, D. Meijer, A. J. Paarlberg, R. P. van Denderen, J. S. de Jong, J. G. W. Beemster, L. A. Melsen, A. J. F. Hoitink
Climate change is expected to increase the frequency and magnitude of river floods1. Floods not only cause damage by inundation and loss of life2,3 but also jeopardize infrastructure because of bank failure and riverbed erosion processes that are poorly understood. Common flood safety programs include dike reinforcement and river widening4-9. The 2021 flood in the Meuse Basin caused 43 fatalities and a multibillion-dollar damage to infrastructure10. Based on analysis of the Meuse flood, we show how uneven widening of the river and heterogeneity of sediment deposits under the river can cause massive erosion. A recent flood safety program widened the river11, but created bottlenecks where widening was either prevented by infrastructure, or not yet implemented. Riverbed erosion was exacerbated by tectonic uplift that had produced a thin top gravel layer above fine-grained sediment. Greatly enhanced flow velocities produced underwater dunes with troughs that broke through the gravel armour in the bottlenecks, exposing easily erodible sands, resulting in extreme scour holes, one over 15 m deep. Our investigation highlights the challenges of re-engineering rivers in the face of climate change, increased flood risks, competition for river widening space, and calls for a better understanding of the subsurface.
Environmental impact, Geomorphology, Natural hazards
Nature Nanotechnology
Iron-silver-modified quantum dots act as efficient catalysts in anti-cancer multitherapy through controlled, ultrasound-induced oxidation
Original Paper | Biomaterials | 2025-07-09 20:00 EDT
Dong Wang, Lei Ji, You Li, Meng Xu, Hao Wang, Sergio Brovelli, Zeng-Ying Qiao, Jiatao Zhang, Yadong Li
Chemodynamic therapy and sonodynamic therapy are two promising tumour therapeutic strategies. However, lack of highly effective sonosensitizers and control over chemodynamic therapy limit their application. Here we synthesize silver-doped zinc selenide quantum dots with atomically dispersed superficial Fe and show that they act as efficient sonosensitizers, catalysers and immunoreagents. Surface modification with an in situ self-assembly peptide drives accumulation in tumours. Superficial FeIII remains stable and converts to FeII only under ultrasonic processing, reverting to FeIII upon ultrasound cessation. Under ultrasound stimulation, superficial Fe undergoes valence change with concomitant amelioration of the hypoxic tumour microenvironment and production of sonodynamic therapy-beneficial hydroxyl radicals. Furthermore, silver doping suppressed nonradiative recombination of excitons, leading to improved production of singlet oxygen. Meanwhile, selenium promotes robust systemic immune responses for the inhibition of tumour metastases. This nano-platform allows control of valence switching of atomically dispersed catalysts, representing an effective tool for chemodynamic/sonodynamic/immunotherapy.
Biomaterials, Nanobiotechnology
Nature Physics
First-principles diagrammatic Monte Carlo for electron-phonon interactions and polaron
Original Paper | Electronic properties and materials | 2025-07-09 20:00 EDT
Yao Luo, Jinsoo Park, Marco Bernardi
In condensed matter, phonons–quanta of the lattice vibration field–couple with electrons, leading to the formation of entangled electron-phonon states called polarons. In the intermediate- and strong-coupling regimes common to many conventional and quantum materials, a many-body treatment of polarons requires adding up a large number of electron-phonon Feynman diagrams. In this regard, diagrammatic Monte Carlo is an efficient method for diagram summation and has been used to study polarons within simplified electron-phonon models. Here we develop diagrammatic Monte Carlo calculations based on accurate first-principles electron-phonon interactions, enabling numerically exact results for the ground-state and dynamical properties of polarons in real materials. We implement these calculations in LiF, SrTiO3, and rutile and anatase TiO2, and describe both localized and delocalized polarons. Our work enables the precise modeling of electron-phonon interactions and polarons in coupling regimes ranging from weak to strong. The results will provide deeper insights into transport phenomena, linear response and superconductivity within the strong electron-phonon coupling regime.
Electronic properties and materials, Electronic structure, Theoretical physics
Science
Macrophage-derived oncostatin M repairs the lung epithelial barrier during inflammatory damage
Research Article | Immunology | 2025-07-10 03:00 EDT
Daisy A. Hoagland, Patricia Rodríguez-Morales, Alexander O. Mann, Alan Y. Baez Vazquez, Shuang Yu, Alicia Lai, Harry Kane, Susanna M. Dang, Yunkang Lin, Louison Thorens, Shahinoor Begum, Martha A. Castro, Scott D. Pope, Jaechul Lim, Shun Li, Xian Zhang, Ming O. Li, Carla F. Kim, Ruaidhrí Jackson, Ruslan Medzhitov, Ruth A. Franklin
Tissue repair programs must function alongside antiviral immunity to restore the lung epithelial barrier following infection. We found that macrophage-derived oncostatin M (OSM) counteracted the pathological effects of type I interferon (IFN-I) during infection and damage in mice. At baseline, OSM-deficient mice exhibited altered alveolar type II (ATII) epithelial cell states. In response to influenza or viral mimic challenge, mice lacking OSM exhibited heightened IFN-I responses and increased mortality. OSM delivery to the lung induced ATII proliferation and was sufficient to protect deficient mice against morbidity. Furthermore, OSM promoted organoid formation despite the growth-inhibitory effects of IFN-I. These findings identify OSM as an indispensable macrophage-derived growth factor that maintains the homeostasis of lung epithelial cells and promotes their proliferation to overcome IFN-I-mediated immunopathology.
ROS transfer at peroxisome-mitochondria contact regulates mitochondrial redox
Research Article | Cell biology | 2025-07-10 03:00 EDT
Laura F. DiGiovanni, Prabhsimran K. Khroud, Ruth E. Carmichael, Tina A. Schrader, Shivneet K. Gill, Kyla Germain, Robert Y. Jomphe, Christoph Wiesinger, Maxime Boutry, Maki Kamoshita, Daniel Snider, Garret Stubbings, Rong Hua, Noel Garber, Christian Hacker, Andrew D. Rutenberg, Roman A. Melnyk, Johannes Berger, Michael Schrader, Brian Raught, Peter K. Kim
Maintenance of mitochondrial redox homeostasis is of fundamental importance to cellular health. Mitochondria harbor a host of intrinsic antioxidant defenses, but the contribution of extrinsic, nonmitochondrial antioxidant mechanisms is less well understood. We found a direct role for peroxisomes in maintaining mitochondrial redox homeostasis through contact-mediated reactive oxygen species (ROS) transfer. We found that ACBD5 and PTPIP51 form a contact between peroxisomes and mitochondria. The percentage of these contacts increased during mitochondrial oxidative stress and helped to maintain mitochondrial health through the transfer of mitochondrial ROS to the peroxisome lumen. Our findings reveal a multiorganelle layer of mitochondrial antioxidant defense–suggesting a direct mechanism by which peroxisomes contribute to mitochondrial health–and broaden the scope of known membrane contact site functions.
Human neuron subtype programming via single-cell transcriptome-coupled patterning screens
Research Article | Neuroscience | 2025-07-10 03:00 EDT
Hsiu-Chuan Lin, Jasper Janssens, Benedikt Eisinger, Philipp Hornauer, Ann-Sophie Kroell, Malgorzata Santel, Maria Pascual-Garcia, Ryoko Okamoto, Kyriaki Karava, Zhisong He, Marthe Priouret, Manuel Schröter, J. Gray Camp, Barbara Treutlein
Human neurons programmed through transcription factor (TF) overexpression model neuronal differentiation and disease. However, the diversity of neuronal subtypes programmable in vitro remains unresolved. We modulated developmental signaling pathways combined with TF overexpression to explore the spectrum of neuron subtypes generated from pluripotent stem cells. We screened 480 morphogen signaling modulations coupled with TF induction using a multiplexed single-cell transcriptomic readout. Analysis of 700,000 cells identified diverse excitatory and inhibitory neurons patterned along the developmental axes of the neural tube. Patterning neural progenitors prior to TF overexpression expanded neuronal diversity by enabling access to regulons active in primary tissue counterparts. Our approach provides a strategy for programming diverse human cell subtypes as well as investigating how cooperative signaling drives neuronal fate.
A single theory for the evolution of sex chromosomes and the two rules of speciation
Research Article | Evolution | 2025-07-10 03:00 EDT
Thomas Lenormand, Denis Roze
Sex chromosomes are involved in three major empirical patterns: (i) Y (or W) chromosomes are often nonrecombining and degenerate; (ii) heterogametic offspring (XY or ZW) from interspecific crosses are more often sterile or inviable compared with homogametic offspring (Haldane’s rule); and (iii) the X (or Z) has a disproportionately large effect on reproductive isolation between species compared with autosomes (the large X effect). Each observation has received its own tailored explanation involving multiple genetic and evolutionary causes. In this work, we show that these empirical patterns all emerge from a single theory for sex chromosome evolution incorporating the coevolution of cis- and trans-acting regulators of gene expression and leading to systematic misexpression of dosage-compensated genes in heterogametic F1 hybrids, for both young and old sex chromosomes.
Discrete spatiotemporal encoding of striatal dopamine transmission
Research Article | Neurophysiology | 2025-07-10 03:00 EDT
Andrew G. Yee, Yini Liao, Brian S. Muntean, Christopher P. Ford
Dopamine (DA) transmission critically regulates diverse, basal ganglia-dependent behaviors by activating distinct subtypes of G protein-coupled receptors. Spatially broad DA release has been extensively characterized, but how DA transmission affects striatal function at a subcellular scale remains poorly understood. Using 2P imaging and whole-cell electrophysiology, we defined the spatiotemporal properties of DA transmission onto striatal indirect pathway spiny projection neurons. Sparse activation of DA release sites evoked localized DA signals, producing spatially discrete, D2 receptor-mediated responses across dendrites. The spatiotemporal properties of DA receptor signaling differed between downstream intracellular pathways. We propose that membrane-delimited Gβγ signaling occurs in parallel to intracellular second messenger pathways, but on different spatial and temporal scales, providing a mechanism for precise decoding of DA signals by striatal neurons.
Spin-filter tunneling detection of antiferromagnetic resonance with electrically tunable damping
Research Article | 2025-07-10 03:00 EDT
Thow Min Jerald Cham, Daniel G. Chica, Xiaoxi Huang, Kenji Watanabe, Takashi Taniguchi, Xavier Roy, Yunqiu Kelly Luo, Daniel C. Ralph
Antiferromagnetic spintronics offers the potential for higher-frequency operations and improved insensitivity to magnetic fields compared to ferromagnetic spintronics. However, previous electrical techniques to detect antiferromagnetic dynamics have utilized large, millimeter-scale bulk crystals. Here we demonstrate direct electrical detection of antiferromagnetic resonance in structures on the few-micrometer scale using spin-filter tunneling in PtTe2/bilayer CrSBr/graphite junctions in which the tunnel barrier is the van der Waals antiferromagnet CrSBr. This sample geometry allows not only efficient detection, but also electrical control of the antiferromagnetic resonance through spin-orbit torque from the PtTe2 electrode. The ability to efficiently detect and control antiferromagnetic resonance enables detailed studies of the physics governing these high-frequency dynamics.
Microglia replacement halts the progression of microgliopathy in mice and humans
Research Article | Neuroscience | 2025-07-10 03:00 EDT
Jingying Wu, Yafei Wang, Xiaoyu Li, Pei Ouyang, Yuanyuan Cai, Yang He, Mengyuan Zhang, Xinghua Luan, Yuxiao Jin, Jie Wang, Yujie Xiao, Yuqing Liang, Fang Xie, Yousheng Shu, Jiong Hu, Chunkang Chang, Jieling Jiang, Dong Wu, Youshan Zhao, Taohui Liu, Yuxin Li, Xiaojun Huang, Yao Li, Junfang Zhang, Yuwen Cao, Xin Cheng, Ying Mao, Yanxia Rao, Li Cao, Bo Peng
Colony-stimulating factor 1 receptor (CSF1R) is primarily expressed in microglia. Its monoallelic mutation causes CSF1R-associated microgliopathy (CAMP), a major form of adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) and a fatal neurological disease without clinical cure. We developed mouse models harboring human hotspot mutations of CAMP and replaced CSF1R-deficient microglia with CSF1R-normal cells through microglia replacement by bone marrow transplantation (Mr BMT), which attenuated pathology in mice. We further demonstrated that, in the context of CSF1R deficiency, traditional bone marrow transplantation (tBMT) in ALSP functions similarly to Mr BMT, efficiently replacing microglia and reducing disease progression. We then replaced CSF1R-deficient microglia in eight patients by tBMT. The disease progression was halted during the 24-month follow-up. Together, microglia replacement corrects pathogenic mutations and halts disease progression in mice and humans.
Cryo-EM structure of human telomerase dimer reveals H/ACA RNP-mediated dimerization
Research Article | Molecular biology | 2025-07-10 03:00 EDT
Sebastian Balch, Zala Sekne, Elsa Franco-Echevarría, Patryk Ludzia, Rachael C. Kretsch, Wenqing Sun, Haopeng Yu, George E. Ghanim, Sigurdur Thorkelsson, Yiliang Ding, Rhiju Das, Thi Hoang Duong Nguyen
Telomerase ribonucleoprotein (RNP) synthesizes telomeric repeats at chromosome ends using a telomerase reverse transcriptase (TERT) and a telomerase RNA (hTR in humans). Previous structural work showed that human telomerase is typically monomeric, containing a single copy of TERT and hTR. Evidence for dimeric complexes exists, although the composition, high-resolution structure, and function remain elusive. Here, we report the cryo-electron microscopy (cryo-EM) structure of a human telomerase dimer bound to telomeric DNA. The structure reveals a 26-subunit assembly and a dimerization interface mediated by the Hinge and ACA box (H/ACA) RNP of telomerase. Premature aging disease mutations map to this interface. Disrupting dimer formation affects RNP assembly, bulk telomerase activity, and telomere maintenance in cells. Our findings address a long-standing enigma surrounding the telomerase dimer and suggest a role for the dimer in telomerase assembly.
Single- and multithread rivers originate from (im)balance between lateral erosion and accretion
Research Article | River dynamics | 2025-07-10 03:00 EDT
Austin J. Chadwick, Evan Greenberg, Vamsi Ganti
Why river channels confine flow to a single pathway or divide flow into multiple interwoven pathways (threads) forms a long-standing fundamental question in river science, which to date remains poorly understood. In this study, we probed channel-pattern origins by mapping thread dynamics along 84 rivers from 36 years of global satellite imagery using particle image velocimetry. Results show that single-thread channels originate from a balance between lateral erosion and accretion, which enables a thread to migrate while maintaining equilibrium width. In contrast, multithread channels originate from imbalance–erosion outpaces accretion in individual threads, causing threads to repeatedly widen and split. Thread-width imbalance provides a mechanistic explanation for how multithread channels develop on Earth and other planets and, in application, can help lower the cost of nature-based river restoration projects.
The forearc seismic belt: A fluid pathway constraining down-dip megathrust earthquake rupture
Research Article | Seismology | 2025-07-10 03:00 EDT
Rintaroh Suzuki, Naoki Uchida, Weiqiang Zhu, Gregory C. Beroza, Takashi Nakayama, Keisuke Yoshida, Genti Toyokuni, Ryota Takagi, Ryosuke Azuma, Akira Hasegawa
A portion of fluids subducted in an oceanic plate is thought to return to Earth’s surface and has the potential to influence faulting during that migration. We used machine learning to detect and locate earthquakes in the northeast Japan forearc using data from a cabled ocean-bottom seismic network. That seismicity shows vertical distributions extending from the subducted plate to near the sea floor. The “forearc seismic belt” corresponds to the seismicity assumed to result from fluid supply from the underlying plate to the forearc and may also act to constrain the down-dip limit of megathrust rupture. The zone of high seismicity continues inland under metropolitan Tokyo, aligning with the Boso slow slip events and the eastern edge of the1923 Kanto earthquake, supporting forecasts of shallow damaging earthquakes.
Origins and diversity of Greenland’s Qimmit revealed with genomes of ancient and modern sled dogs
Research Article | Dog domestication | 2025-07-10 03:00 EDT
T. R. Feuerborn, M. Appelt, K. Bougiouri, L. Bachmann, I. Broman Nielsen, R. M. Buckley, C. Egevang, P. Fernandez Diaz-Maroto, S. Gopalakrishnan, A. B. Gotfredsen, K. M. Gregersen, B. Grønnow, M. Lund Jensen, C. K. Madsen, U. Markussen, Å. Midtdal, A. L. Schmidt, A. Serres Armero, E. Vitale, Ø. Wiig, G. Zhang, L. Dalén, L. A. F. Frantz, M. T. P. Gilbert, M. Meldgaard, E. A. Ostrander, M.-H. S. Sinding, A. J. Hansen
The Qimmeq (Greenland sled dog) has worked continuously with the Inuit in Greenland for more than 800 years. However, they now face drastic population declines caused by climate change, urbanization, and competition from snowmobiles. This study sequenced 92 modern and ancient genomes to investigate how centuries of isolation shaped the regional Qimmeq populations and the impact of European contact. We found distinct regional populations and evidence for two migrations of dogs into Greenland with the Inuit from Canada. Furthermore, we found that there is minimal European ancestry in present day Qimmit and limited recent inbreeding despite low heterozygosity. These insights are critical for conservation efforts aimed at preserving the Qimmit amid environmental changes and cultural transitions.
Compartmentalization reduces conflict in multipartner plant-insect symbioses
Research Article | Mutualism | 2025-07-10 03:00 EDT
Guillaume Chomicki, Dirk Metzler, Alivereti Naikatini, Susanne S. Renner
Many symbioses involve one host species having several mutualist partners, yet theory predicts that unrelated symbionts lead to destabilizing conflict through competition for host resources. We combined isotope labeling, computed-tomography three-dimensional models, behavioral field experiments, and mathematical models to show that Squamellaria plant hosts reduce conflict among their multiple ant symbiont species by offering nesting sites (domatia) divided into compartments with separate entrances. As long as compartmentalization is maintained, different symbiont species can peacefully coexist, but experimental removal of compartment walls leads to deadly conflicts. Modeling suggests that compartmentalization optimizes nutritional benefits by increasing the time during which domatia harbor large ant colonies. These results reveal a conflict-reduction mechanism that allows hosts to take advantage of unrelated symbionts, which may be widespread in multipartner mutualisms.
Tissue-integrated bionic knee restores versatile legged movement after amputation
Research Article | Prosthetics | 2025-07-10 03:00 EDT
Tony Shu, Daniel Levine, Seong Ho Yeon, Ethan Chun, Christopher C. Shallal, John McCullough, Rickard Brånemark, Matthew J. Carty, Marco Ferrone, Sean Boerhout, Alexander Ko, Corey L. Sullivan, Gloria Zhu, Michael Nawrot, Matthew Carney, Ged Wieschhoff, Gabriel Friedman, Hugh Herr
Lower-extremity prostheses have evolved through mechanical redesigns that prioritize improved cyclic locomotion. However, this limited approach to limb restoration has precluded necessary progress toward recovering the versatile acyclic movements that constitute the remainder of human athleticism. We present an osseointegrated mechanoneural prosthesis that incorporates modified hard and soft tissues along with permanently implanted hardware in a neuroembodied design. We developed a biomimetic coupling between neuromuscular signaling and joint movement that exceeds the versatility of established control methods, which depend upon conventional amputation musculature and surface electromyography. Our findings also reveal that superior residual neuromuscular function can enable prosthetic movement speeds surpassing that of intact physiology. Anatomical prosthetic integration may be necessary for meeting, and possibly exceeding, the movement capabilities of an intact limb.
Overturning circulation structures the microbial functional seascape of the South Pacific
Research Article | Ocean ecology | 2025-07-10 03:00 EDT
Bethany C. Kolody, Rohan Sachdeva, Hong Zheng, Zoltán Füssy, Eunice Tsang, Rolf E. Sonnerup, Sarah G. Purkey, Eric E. Allen, Jillian F. Banfield, Andrew E. Allen
Global overturning circulation partitions the deep ocean into regions, each with different physicochemical characteristics, but the extent to which these water masses represent distinct ecosystems remains unknown. In this work, we integrate extensive genomic information with hydrography and water mass age to delineate microbial taxonomic and functional boundaries across the South Pacific. Prokaryotic richness steeply increases with depth in the surface ocean, which forms a so-called phylocline, below which, richness is consistently high, dipping slightly in highly aged water. Reconstructed genomes self-organize into six spatially distinct taxonomic cohorts and 10 functionally distinct biomes that are primarily structured by wind-driven circulation at the surface and density-driven circulation at depth. Overall, water physicochemistry, modulated at depth by water age, drives microbial diversity patterns and functional potential in the pelagic ocean.
Scalable emulation of protein equilibrium ensembles with generative deep learning
Research Article | 2025-07-10 03:00 EDT
Sarah Lewis, Tim Hempel, José Jiménez-Luna, Michael Gastegger, Yu Xie, Andrew Y. K. Foong, Victor García Satorras, Osama Abdin, Bastiaan S. Veeling, Iryna Zaporozhets, Yaoyi Chen, Soojung Yang, Adam E. Foster, Arne Schneuing, Jigyasa Nigam, Federico Barbero, Vincent Stimper, Andrew Campbell, Jason Yim, Marten Lienen, Yu Shi, Shuxin Zheng, Hannes Schulz, Usman Munir, Roberto Sordillo, Ryota Tomioka, Cecilia Clementi, Frank Noé
Following the sequence and structure revolutions, predicting functionally relevant protein structure changes at scale remains an outstanding challenge. We introduce BioEmu, a deep learning system that emulates protein equilibrium ensembles by generating thousands of statistically independent structures per hour on a single GPU. BioEmu integrates over 200 milliseconds of molecular dynamics (MD) simulations, static structures and experimental protein stabilities using novel training algorithms. It captures diverse functional motions–including cryptic pocket formation, local unfolding, and domain rearrangements–and predicts relative free energies with 1 kcal/mol accuracy compared to millisecond-scale MD and experimental data. BioEmu provides mechanistic insights by jointly modelling structural ensembles and thermodynamic properties. This approach amortizes the cost of MD and experimental data generation, demonstrating a scalable path toward understanding and designing protein function.
Harnessing carbene polarity: Unified catalytic access to donor, neutral, and acceptor carbenes
Research Article | Organic chemistry | 2025-07-10 03:00 EDT
Khue N. M. Nguyen, Xueling Mo, Bethany M. DeMuynck, Mohamed Elsayed, Jacob J. A. Garwood, Duong T. Ngo, Ilias Khan Rana, David A. Nagib
Metal carbenes are highly useful intermediates in organic synthesis. However, not all classes of carbene polarity are catalytically accessible, nor are there common precursors known to synthesize all of these electronically diverse carbene types. Here, we report a unified strategy to access a full range of carbenes, including those with donor substituents (EDG: OMe, NR2, alkyl), acceptor substituents (EWG: CN, CO2R), and electronically neutral or nonpolar substituents (H, BR2, SiR3, halide, aryl, heteroaryl). This Fe-catalyzed method harnesses α-Cl radicals and couples an exceptionally wide array of carbenes in (2+1) cyclopropanations and σ-bond insertions. This mild, robust, and electronically tunable synthetic method facilitated the development of a better classification system for catalytic metal carbenes (validated by both kinetic and thermodynamic quantification), as well as a carbene “click-like” reaction and aqueous adaptation for chemical biology applications.
Negative capacitance overcomes Schottky-gate limits in GaN high-electron-mobility transistors
Research Article | 2025-07-10 03:00 EDT
Asir Intisar Khan, Jeong-Kyu Kim, Urmita Sikder, Koushik Das, Thomas Rodriguez, Rohith Soman, Srabanti Chowdhury, Sayeef Salahuddin
For high-electron-mobility transistors based on two-dimensional electron gas (2DEG) within a quantum well, such as those based on AlGaN/GaN heterostructure, a Schottky-gate is used to maximize the amount of charge that can be induced and thereby the current that can be achieved. However, the Schottky-gate also leads to very high leakage current through the gate electrode. Adding a conventional dielectric layer between the nitride layers and gate metal can reduce leakage; but this comes at the price of a reduced drain current. Here, we used a ferroic HfO2- ZrO2 bilayer as the gate dielectric and achieved a simultaneous increase in the ON current and decrease in the leakage current, a combination otherwise not attainable with conventional dielectrics. This approach surpasses the conventional limits of Schottky GaN transistors and provides a new pathway to improve performance in transistors based on 2DEG.
Physical Review Letters
Counterdiabatic Route to Entanglement Steering and Dynamical Freezing in the Floquet Lipkin-Meshkov-Glick Model
Research article | Quantum control | 2025-07-09 06:00 EDT
Nakshatra Gangopadhay and Sayan Choudhury
Controlling the dynamics of quantum many-body systems is crucial for developing quantum technologies. This work demonstrates that counterdiabatic (CD) driving provides a powerful tool for steering collective spin systems along entangled trajectories for a long time. In particular, CD driving leads to approximate stroboscopic freezing and eternal entanglement oscillations for a large class of initial states in the periodically driven Lipkin-Meshkov-Glick model. Intriguingly, CD driving generates spin squeezing and its associated metrologically useful multipartite entanglement at the mid-point of every drive cycle, when the system is initially prepared in a fully $x$-polarized state. The CD driving induced nonergodic dynamics is accompanied by a decrease in the average eigenstate entanglement and inverse participation ratio, thereby signaling greater eigenstate localization. Our work opens a new route to evade Floquet heating and control entanglement generation in collective spin systems.
Phys. Rev. Lett. 135, 020407 (2025)
Quantum control, Quantum protocols, Floquet systems
Observation of Spin Squeezing with Contact Interactions in One- and Three-Dimensional Easy-Plane Magnets
Research article | Cold gases in optical lattices | 2025-07-09 06:00 EDT
Yoo Kyung Lee, Maxwell Block, Hanzhen Lin (林翰桢), Vitaly Fedoseev, Philip J. D. Crowley, Norman Y. Yao, and Wolfgang Ketterle
Spin squeezing in a many-body system is a witness for entanglement and can enable measurement sensitivities beyond those achievable by only classical correlations. Here, working with ultracold $^{7}\mathrm{Li}$ atoms in an optical lattice, we demonstrate spin squeezing using short-range contact interactions in both one and three dimensions. In 1D, spin squeezing is shown to be insensitive to density fluctuations caused by holes. In 3D, however, we observe that holes strongly modify the squeezing dynamics, hindering the recently predicted emergence of scalable squeezing in 3D $XXZ$ spin systems. By developing a new theoretical model to account for spin-density coupling, we obtain strong quantitative agreement with the observed squeezing dynamics, resulting in $\approx 2\text{ }\text{ }\mathrm{dB}$ at 7% hole fraction. Our observations highlight the importance of understanding spin-density coupling in the dynamics of many interacting spins and lay the groundwork for improved spin squeezing in systems with only short-range interactions.
Phys. Rev. Lett. 135, 023402 (2025)
Cold gases in optical lattices, Entanglement in quantum gases, Entanglement production, Quantum metrology, Quantum simulation, Ultracold gases, Optical lattices & traps
Observation of Fermi Acceleration with Cold Atoms
Research article | Atom & ion trapping & guiding | 2025-07-09 06:00 EDT
G. Barontini, V. Naniyil, J. P. Stinton, D. G. Reid, J. M. F. Gunn, H. M. Price, A. B. Deb, D. Caprioli, and V. Guarrera
A mechanism for accelerating charged particles in astrophysical plasmas has been reproduced with cold atoms in an optical trap.
Phys. Rev. Lett. 135, 025201 (2025)
Atom & ion trapping & guiding, Atom optics, Atomtronics, Cosmic ray acceleration, Cosmic ray composition & spectra, Plasma acceleration & new acceleration techniques, Space & astrophysical plasma
Extracting Nonlinear Dynamical Response Functions from Time Evolution
Research article | Nonlinear optics | 2025-07-09 06:00 EDT
Atsushi Ono
We develop a general framework based on the functional derivative to extract nonlinear dynamical response functions from the temporal evolution of physical quantities, without explicitly computing multipoint correlation functions. We validate our approach by calculating the second- and third-order optical responses in the Rice–Mele model and further apply it to a many-body interacting system using a tensor network method. This framework is broadly applicable to any method that can compute real-time dynamics, offering a powerful and versatile tool for investigating nonlinear responses in dynamical systems.
Phys. Rev. Lett. 135, 026401 (2025)
Nonlinear optics, Dynamical systems, Nonequilibrium systems, Numerical approximation & analysis
Fluctuations and Correlations of Local Topological Order Parameters in Disordered Two-Dimensional Topological Insulators
Research article | Chern insulators | 2025-07-09 06:00 EDT
Roberta Favata, Nicolas Baù, and Antimo Marrazzo
Space-resolved topological markers characterizing disorder-driven topological phase transitions act as local order parameters.
Phys. Rev. Lett. 135, 026603 (2025)
Chern insulators, Critical phenomena, Electronic structure, Order parameters, Quantum anomalous Hall effect, Quantum spin Hall effect, Topological phase transition, Vacancies, Disordered systems, Topological insulators
Experimental Realization of Special-Unitary Operations in Classical Mechanics by Nonadiabatic Evolutions
Research article | Classical mechanics | 2025-07-09 06:00 EDT
Congwei Lu, Xulong Wang, and Guancong Ma
Artificial classical wave systems such as wave crystals and metamaterials have demonstrated promising capabilities in simulating a wide range of quantum mechanical phenomena. Yet some gaps between quantum and classical worlds are generally considered fundamental and difficult to bridge. Dynamics obeying special unitary groups, e.g., electronic spins described by SU(2), color symmetries of fundamental particles described by SU(3), are such examples. In this Letter, we present the experimental realization of universal SU(2) and SU(3) dynamic operations in classical mechanical oscillator systems with temporally modulated coupling terms. Our approach relies on the sequential execution of nonadiabatic holonomic evolutions, which are typically used in constructing quantum-logic gates. The method is swift and purely geometric and can be extended to realize more sophisticated dynamic operations. Our results open a new way for studying and simulating quantum phenomena in classical systems.
Phys. Rev. Lett. 135, 027201 (2025)
Classical mechanics, Quantum simulation, SU(N) symmetries
Colloidal Model for Investigating Optimal Efficiency in Weakly Coupled Ratchet Motors
Research article | Biomolecular processes | 2025-07-09 06:00 EDT
José Martín-Roca, Laura Izquierdo Solis, Fernando Martínez Pedrero, Pau Casadejust, Ignacio Pagonabarraga, and Carles Calero
We investigate the transport of superparamagnetic colloidal particles along self-assembled tracks using a periodically applied magnetic field as a model for ratchetlike mechanisms. Through video microscopy and simulations, we examine how different factors influence transport efficiency. The findings reveal that processive motion can be achieved without residual attraction, with optimal transport efficiency governed by the combined effects of particle size ratios, actuation frequency, track roughness, and asymmetry in the applied potential. Additionally, we explore alternative strategies, including weak residual attraction and alternating magnetic fields, to further enhance efficiency. These findings provide valuable insights for the development of synthetic micro- and nanomotors with potential applications in drug delivery and environmental remediation.
Phys. Rev. Lett. 135, 028301 (2025)
Biomolecular processes, Magnetic interactions, Processes in cells, tissues & organoids, Swarming, Brownian ratchet, Living matter & active matter, Brownian dynamics, Imaging & optical processing, Molecular dynamics, Optical microscopy
Physical Review X
From the Dawn of Neutrino Astronomy to a New View of the Extreme Universe
Perspective | Cosmic rays & astroparticles | 2025-07-09 06:00 EDT
C. A. Argüelles, F. Halzen, and N. Kurahashi
This Perspective outlines the history of neutrino astronomy and looks ahead to the big questions that neutrino observatories may help answer.
Phys. Rev. X 15, 030501 (2025)
Cosmic rays & astroparticles, Particle astrophysics, Particle dark matter, Neutrinos, Neutrino mass
Coherent Structure Interactions in Spatially Extended Systems Driven by Excited Hidden Modes
Research article | Bifurcations | 2025-07-09 06:00 EDT
Alex Round, Te-Sheng Lin, Marc Pradas, Dmitri Tseluiko, and Serafim Kalliadasis
Spectral theory reveals a hidden bifurcation driving self-sustained dynamics in falling liquid films, with broad interdisciplinary implications for understanding how coherent structures interact and organize the resulting nonlinear dynamics.
Phys. Rev. X 15, 031010 (2025)
Bifurcations, Capillary waves, Complex systems, Emergence of patterns, Flow instability, Interfacial flows, Low Reynolds number flows, Low-dimensional models, Mathematical physics, Nonlinear dynamics in fluids, Pattern formation, Patterns in complex systems, Solitary waves, Spatiotemporal chaos, Surface tension effects, Thin fluid films, Waves and free surface flows
arXiv
Probing microsecond dynamics of disperse nanoparticles at oil-water interfaces using nanometer localization precision total-internal-reflection dark-field microscopy
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-10 20:00 EDT
Particles at fluid-fluid interfaces have a wide range of important applications in industry, technology and science. Questions remain about what governs adsorption dynamics and inter-particle interactions, and how mixtures – both of different-sized particles, and particles and surfactants – behave. I probe the dynamics of nanoparticles at oil-water interfaces using high-speed total-internal-reflection dark-field (TIR-DF) microscopy, comparing gold particles of diameters 20, 40 and 80 nanometers, and investigating the effect of an added surfactant. I built a TIR-DF microscope with a spatiotemporal resolution of up to 1 nanometer at 20 microseconds, and characterized the particle motion by direct imaging for the diffusive motion within the interfacial plane, and attenuation of light scattering and in-plane motion for out-of-plane motion. The addition of surfactant was found to qualitatively alter the interaction between the particles and the interface: Adsorptions became reversible and the size trend in diffusivity was reversed (larger particles diffused faster than smaller ones). The combination of this and the rarity of adsorption events of larger particles leads me to propose size-dependent barriers to adsorption at surfactant interfaces. In addition, at surfactant interfaces, many particles’ diffusive behavior changed over the course of a trajectory, indicating several different immersion states that are stable on the experimental timescale (approximately 1 second). This study shows that there remain qualitatively new dynamics of nanoparticles at oil-water interfaces to be explored. These dynamics can only be resolved at a high spatial resolution, and many of them only at high imaging speed, underlining the importance of novel imaging approaches probing the barriers of achievable spatiotemporal resolution.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
Instabilities and turbulence in extensile swimmer suspensions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-10 20:00 EDT
Purnima Jain, Navdeep Rana, Roberto Benzi, Prasad Perlekar
We study low Reynolds number turbulence in a suspension of polar, extensile, self-propelled inertial swimmers. We review the bend and splay mechanisms that destabilize an ordered flock. The suspension is always unstable to bend perturbations. Using a minimal 1D model, we show that the splay-stable to splay-unstable transition occurs via a supercritical Hopf bifurcation. We perform high-resolution numerical simulations in 2D to study the varieties of turbulence present in this system transitioning from defect turbulence to concentration-wave turbulence depending on a single non-dimensional number, denoting the ratio of the splay-concentration wavespeed to the swimmer motility.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
8 pages, 8 figures
Scaling of Structure and Dynamics in Molecular Liquids: Insights from Pressure Experiments and Molecular Dynamics
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-10 20:00 EDT
The overall goal of this thesis is to investigate the connection between the dynamics and structure of molecular glass formers, by testing different scaling laws for both. The inspiration for this work is the Isomorph theory because it predicts a connection between structure and dynamics. The fundamental prediction of the Isomorph Theory is that there exist lines in the phase diagram where both structure and dynamics are invariant when presented in reduced units. The prediction of constant dynamics has been tested and confirmed experimentally several times, but the structural prediction has never been confirmed experimentally. In this thesis, we have investigated the structural prediction for liquids where the prediction of constant dynamics has been shown experimentally.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci)
PhD thesis, 175 pages. For full abstract, see text
Superconducting Photocurrent and Light Enriched Supercurrent Phase Relation
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-10 20:00 EDT
Oles Matsyshyn, Justin C. W. Song
Noncentrosymmetric superconductors are expected to exhibit DC photocurrents even for irradiation frequencies below the superconducting gap. Such superconducting photocurrent are non-dissipative and track the quantum geometry of the superconducting state. Here we argue that superconducting photocurrent drives changes to the constitutive superconducting current phase relation (CPR) manifesting in a light controlled inductive response as well as altering the critical current. For chiral incident light, we find that superconducting photocurrent can transform reciprocal CPR into a non-reciprocal CPR producing a non-reciprocal inductance and light-controlled superconducting diode effect. These provide a protocol for measuring superconducting photocurrent and new tools for mapping the quantum geometry and order parameter of superconductors.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 2 figures
Entanglement switching via mobility edges in a quasiperiodic chain
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-10 20:00 EDT
YouYoung Joung, Junmo Jeon, SungBin Lee
We propose quasiperiodic chains with tunable mobility edge physics, as a promising platform for engineering long-range quantum entanglement. Using the generalized Aubry-André model, we show that the mobility edges play a key role in manipulating long-range indirect interactions in these systems. Near the mobility edge, critical states exhibit unexpectedly strong correlations between sites that share similar local structures, regardless of their spatial separation. Remarkably, by tuning the mobility edge across the Fermi level, one can induce both adiabatic transport and abrupt switching of entanglement between distant sites. These results highlight the potential of aperiodic structures for controlling nonlocal quantum correlations, opening new avenues for entanglement-based applications in quasiperiodic systems.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
7 pages, 3 figures
Spin-orbital magnetism in moiré Wigner molecules
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-10 20:00 EDT
Ahmed Khalifa, Rokas Veitas, Francisco Machado, Shubhayu Chatterjee
The interplay of spin and orbital degrees of freedom offers a versatile playground for the realization of a variety of correlated phases of matter. However, the types of spin-orbital interactions are often limited and challenging to tune. Here, we propose and analyze a new platform for spin-orbital interactions based upon a lattice of Wigner molecules in moire transition metal dichalcogenides (TMDs). Leveraging the spin-orbital degeneracy of the low-energy Hilbert space of each Wigner molecule, we demonstrate that TMD materials can host a general spin-orbital Hamiltonian that is tunable via the moiré superlattice spacing and dielectric environments. We study the phase diagram for this model, revealing a rich landscape of phases driven by spin-orbital interactions, ranging from ferri-electric valence bond solids to a helical spin liquid. Our work establishes moiré Wigner molecules in TMD materials as a prominent platform for correlated spin-orbital phenomena
Strongly Correlated Electrons (cond-mat.str-el)
6+15 pages, 4+5 figures
Strange metal and Fermi arcs from disordering spin stripes
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-10 20:00 EDT
We revisit the effective theory for fluctuating spin stripes coupled to a Fermi surface, and consider the parameter regime where a spin nematic phase intervenes between the spin density wave state and the symmetric state. It is shown that adding potential disorder to this theory, which acts as an unconventional type of random-field disorder, naturally gives rise to the universal theory of strange metals with spatial disorder in both the magnitude and sign of the electron-boson coupling term [A.A. Patel, H. Guo, I. Esterlis and S. Sachdev, Science 381, 790 (2023)]. One difference compared to the original theory, however, is that at non-zero temperatures the disordered spin-stripe model automatically self-averages over the sign of the coupling. We also study the effects of thermal fluctuations in a phenomenological model for the disordered spin density wave state, and find from Monte Carlo simulations that a short anti-ferromagnetic correlation length (order 4-5 lattice constants) already leads to pronounced Fermi arcs in the electronic spectral weight.
Strongly Correlated Electrons (cond-mat.str-el)
Spin precession and laser-induced spin-polarized photocurrents
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Esteban A. Rodríguez-Mena, Matías Berdakin, Luis E. F. Foa Torres
Controlling spin currents in topological insulators (TIs) is crucial for spintronics but challenged by the robustness of their chiral edge states, which impedes the spin manipulation required for devices like spin-field effect transistors (SFETs). We theoretically demonstrate that this challenge can be overcome by synergistically applying circularly polarized light and gate-tunable Rashba spin-orbit coupling (rSOC) to a 2D TI. Laser irradiation provides access to Floquet sidebands where rSOC induces controllable spin precession, leading to the generation of one-way, switchable spin-polarized photocurrents, an effect forbidden in equilibrium TIs. This mechanism effectively realizes SFET functionality within a driven TI, specifically operating within a distinct Floquet replica, offering a new paradigm for light-based control in topological spintronics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
7 pages, 6 figures
Enhanced Andreev Reflection in Flat-Band Systems: Wave Packet Dynamics, DC Transport and the Josephson Effect
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-10 20:00 EDT
Sarbajit Mazumdar, Anamitra Mukherjee, Kush Saha, Sourin Das
We investigate Andreev reflection (AR) in a proximity-induced normal-superconductor (NS) junction within the extended $ \alpha-\mathcal{T}_3$ lattice, emphasizing the impact of flat bands on AR. Our findings reveal that flat bands significantly enhance AR. Through wave packet dynamics, we track the real-time evolution of quasi-particle wave packets across the junction, providing deeper insight into electron-hole conversion. Notably, the combination of band flatness and anisotropic dispersion in the $ k_x-k_y$ plane induces an electronic analog of Goos-Hänchen (GH) shifts at the NS interface, exhibiting directional asymmetry along the junction. This asymmetry leads to a Hall-like response in Josephson junction in SNS geometry, where transport across the junction region is dominated by the quasi-flat bands.
Superconductivity (cond-mat.supr-con)
13 pages, 11 figures
Thermal Transport and Application Reassessment of ThSi$_2$N$_4$ Monolayer: From FET Channel to Thermoelectric Material
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Maryam Mirzaei Farshmi, Seyedeh Ameneh Bahadori, Zahra Shomali
The two-dimensional M$ _2$ Z$ _4$ materials are proposed as suitable replacements for silicon channels in field-effect transistors (FETs). In the present work, the ThSi$ _2$ N$ _4$ monolayer from the family, with the very appropriate electron mobility, is thermally investigated using the non-equilibrium Monte Carlo simulation of the phonon Boltzmann transport equation. The reliability of the MOSFET with the ThSi$ _2$ N$ _4$ channel has been reassessed and determined to be low due to the high maximum temperature achieved. The phonon analysis is performed and reveals that the dominant contribution of fast and energetic LA and also slow and low energy ZA phonons alongside the minor participation of the TA phonons is responsible for the peak temperature rise reaching 800 K. This finding presents that the ThSi$ _2$ N$ _4$ monolayer is not a good candidate for replacing as silicon channel but alternatively is capable of generating a significant temperature gradient, which makes it, a suitable candidate for using as a thermoelectric material in thermoelectric generators.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Terahertz field-induced metastable magnetization near criticality in FePS3
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Batyr Ilyas, Tianchuang Luo, Alexander von Hoegen, Emil Viñas Boström, Zhuquan Zhang, Jaena Park, Junghyun Kim, Je-Geun Park, Keith A. Nelson, Angel Rubio, Nuh Gedik
Controlling the functional properties of quantum materials with light has emerged as a frontier of condensed-matter physics, leading to the discovery of various light-induced phases of matter, such as superconductivity, ferroelectricity, magnetism and charge density waves. However, in most cases, the photoinduced phases return to equilibrium on ultrafast timescales after the light is turned off, limiting their practical applications. Here we use intense terahertz pulses to induce a metastable magnetization with a remarkably long lifetime of more than 2.5 milliseconds in the van der Waals antiferromagnet FePS3. The metastable state becomes increasingly robust as the temperature approaches the antiferromagnetic transition point, suggesting that critical order parameter fluctuations play an important part in facilitating the extended lifetime. By combining first-principles calculations with classical Monte Carlo and spin dynamics simulations, we find that the displacement of a specific phonon mode modulates the exchange couplings in a manner that favours a ground state with finite magnetization near the Néel temperature. This analysis also clarifies how the critical fluctuations of the dominant antiferromagnetic order can amplify both the magnitude and the lifetime of the new magnetic state. Our discovery demonstrates the efficient manipulation of the magnetic ground state in layered magnets through non-thermal pathways using terahertz light and establishes regions near critical points with enhanced order parameter fluctuations as promising areas to search for metastable hidden quantum states.
Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el), Optics (physics.optics)
33 pages, 4 figures
Nature 636 (2024) 609-614
Tuning of electronic properties in highly lattice-mismatched epitaxial SmN
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
K.D. Vallejo, V. Buturlim, Z. Cresswell, B. Campbell, B.G. Duersch, B.J. May, K. Gofryk
We demonstrate that the electronic properties of epitaxial SmN thin films can be effectively tuned during growth by controlling the synthesis parameters. By carefully adjusting these parameters, we are able to drive SmN from an insulating ferromagnetic state to a ferromagnetic metallic state. However, no signatures of previously reported superconductivity were observed down to 0.35 K, even in the most conductive samples. We discuss possible scenarios for the absence of superconductivity in these films and examine implications for the underlying pairing mechanism in this material. These findings open a new pathway for the epitaxial engineering of multifunctional materials, enabling the monolithic integration of diverse electronic phases, such as ferromagnetism and metallicity, without the lattice mismatch and strain typically associated with heteroepitaxial growth of dissimilar materials.
Materials Science (cond-mat.mtrl-sci), Atomic Physics (physics.atom-ph)
Randomly measured quantum particles and thermal noise
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-10 20:00 EDT
We consider the motion of a quantum particle whose position is measured in random places at random moments in time. We contrast this motion with the motion of a quantum particle in a potential which varies randomly in space and in time, which could also be thought of as (possibly thermal) noise. We calculate expectations of observables both linear and nonlinear in the density matrix. We demonstrate explicitly that while linear observables cannot distinguish between random measurements and random noise, measurable distinctions can be seen in nonlinear observables.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
Bilayer graphene as a template for manufacturing novel 2D materials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Arkady V. Krasheninnikov, Yung-Chang Lin, Kazu Suenaga
Recent intensive research on two-dimensional materials (2DMs) rekindle the interest in the intercalation of various atoms and molecules into layered compounds as a tool to manufacture 2DMs and tune their optoelectronic, magnetic and catalytic properties. Intercalation into free-standing bilayer graphene (BLG) has received special attention, as graphene is stable, chemically inert and enables one to study the atomic structure of the intercalated 2DM using high-resolution transmission electron microscopy. It was also discovered that the protecting action of graphene sheets makes it possible to not only stabilize the encapsulated single sheets of marginally stable layered materials, but also synthesize completely new 2D systems inside BLG, which in comparison to the bulk graphite allows for easier intercalation and much larger increase in the inter-layer separation of the sheets. In this review, we summarize the recent progress in this area, with a special focus on new materials created inside BLG. We compare the experimental findings to the theoretical predictions, pay special attention to the discrepancies and outline the challenges in the field. Finally, we discuss unique opportunities offered by the intercalation into 2DMs beyond graphene and their heterostructures.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Hot Phonon Bottlenecks and the Role of Non-Equilibrium Acoustic Phonons in III-V Multi-Quantum Well Systems
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Izak Baranowski, Dragica Vasileska, Ian R. Sellers, Stephen M. Goodnick
The hot phonon bottleneck effect is a promising mechanism for the realization of a true hot carrier solar cell. Prior work has assumed that the acoustic phonons created via decay of polar longitudinal optical (LO) phonons are assumed to quickly leave the system or thermalize quickly due to multi-phonon processes. The present work furthers the models of previous work to include a build-up of longitudinal acoustic phonons in addition to LO phonons due via the Klemens process. By including this additional process, nonphysical assumptions concerning the LO anharmonic lifetime are no longer required, resulting in a better explanation of the experimental results, and pointing towards new approaches in achieving high carrier temperatures during photo-excitation.
Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures
Gap reopening as signature of coupling between Majorana zero modes in Sn-(Bi,Sb)2(Te,S)3-based Josephson trijunctions
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-10 20:00 EDT
Duolin Wang, Xiang Zhang, Yunxiao Zhang, Heng Zhang, Fucong Fei, Xiang Wang, Bing Li, Xiaozhou Yang, Yukun Shi, Zhongmou Jia, Enna Zhuo, Yuyang Huang, Anqi Wang, Zenan Shi, Zhaozheng Lyu, Xiaohui Song, Peiling Li, Bingbing Tong, Ziwei Dou, Jie Shen, Guangtong Liu, Fanming Qu, Fengqi Song, Li Lu
In the past two decades, enormous efforts have been made to search for possible platforms and schemes to implement topological quantum computation (TQC). In exploring the Fu-Kane scheme of TQC based on Josephson trijunctions constructed on topological insulators, the expected Majorana phase diagram of a single trijunction has been experimentally verified. If Majorana zero modes indeed exist in this kind of trijunctions, coupling between them in multiple trijunction devices would be further expected. In this study, we fabricated Josephson devices containing two adjacent Josephson trijunctions on the surface of Sn-(Bi,Sb)2(Te,S)3, and observed that the minigap reopens for both trijunctions in their phase spaces where a closure would otherwise be expected if the trijunctions existed independently. Our findings would provide new experimental support for the validity of the Fu-Kane theory and instill further confidence in advancing along the TQC scheme proposed by Fu and Kane.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
3 figures
Effects of multiple cycles on the resistance distance of a strand in a homogeneous polymer network
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-10 20:00 EDT
We show that the resistance distance between a pair of adjacent vertices in a phantom network generated randomly by a Monte-Carlo method depends on the existence of short cycles around it. Here we assume that phantom networks have no fixed points but their centers of mass are located at a point. The resistance distance corresponds to the mean-square deviation of the end-to-end vector along the strand connecting the adjacent vertices. We generate random networks with fixed valency $ f$ but different densities of short cycles via a Metropolis method that rewires edges among four vertices chosen randomly. In the process the cycle rank is conserved. However, the densities of short cycles are determined by the rate of randomization $ kT$ which appears in the acceptance ratio $ \exp(-\Delta U/kT)$ of rewiring. If a strand has few short cycles around itself, the mean squared deviation of the strand is equal to $ 2/f$ . If it is part of a short cycle, i.e., the network has a short loop which consists of a sequence of strands including the given strand itself, its resistance distance is smaller than $ 2/f$ , while if it is not included in a cycle but adjacent to cycles, its resistance distance is larger than $ 2/f$ . We show it via an electrical circuit analogy of the network. Moreover, we numerically show that the effect of multiple cycles on the resistance distance is expressed as a linear combination of the effects of isolated single cycles. It follows that cycles independently have an effect on the fluctuation properties of a strand in a polymer network.
Soft Condensed Matter (cond-mat.soft)
High Proton Conductivity of HxWO3 at Intermediate Temperatures: Unlocking Its Application as a Mixed Ionic-Electronic Conductor
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Rantaro Matsuo, Tomoyuki Yamasaki, Takahisa Omata
Hydrogen tungsten bronzes (HxWO3), known for their mixed protonic-electronic conduction near room temperature, are extensively studied for electrochromic and gasochromic applications. However, their proton transport properties at elevated temperatures, particularly in the intermediate-temperature range (200-500 °C), remain unexplored. This study revealed the proton transport behavior of HxWO3, focusing on its potential as a proton-conducting mixed ionic-electronic conductor (MIEC) for intermediate-temperature electrochemical applications. By employing a proton-conducting phosphate glass as an electron-blocking electrode, we selectively measured the partial proton conductivity of sintered HxWO3. Hydrogen incorporation into the sintered WO3 pellet was found to occur preferentially near the surface, forming an approximately 500-micrometer-thick hydrogen-rich region. This region reached a composition of x = 0.24 and exhibited proton conductivity exceeding 10^-1 S/cm at 275 °C, well above those of state-of-the-art perovskite proton conductors. Impedance spectroscopy revealed distinct features of proton transport, including an isotope effect. The proton diffusion coefficient was 100-1000 times greater than that of H0.0001TiO2, which exhibits mixed protonic-electronic conduction via hydrogen dissolution. The larger proton diffusion coefficient of H0.24WO3 suggests that large polaron formation enhances proton this http URL findings unlock new functionality of HxWO3 as a MIEC in the intermediate-temperature range, paving the way for the development of next-generation hydrogen energy conversion systems.
Materials Science (cond-mat.mtrl-sci), Disordered Systems and Neural Networks (cond-mat.dis-nn)
Algebraic States in Continuum in $ d\gt 1$ Dimensional Non-Hermitian Systems
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
We report the existence of algebraically localized eigenstates embedded within the continuum spectrum of 2D non-Hermitian systems with a single impurity. These modes, which we term algebraic states in continuum (AICs), decay algebraically as $ 1/|r|$ from the impurity site, and their energies lie within the bulk continuum spectrum under periodic boundary conditions. We analytically derive the threshold condition for the impurity strength required to generate such states. Remarkably, AICs are forbidden in Hermitian systems and in 1D non-Hermitian systems, making them unique to non-Hermitian systems in two and higher dimensions. To detect AICs, we introduce a local density of states as an experimental observable, which is readily accessible in photonic/acoustic platforms.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
9 pages, 3 figures
Observation of Macroscopic Nonlocal Voltage and Hydrodynamic Electron Flow at Room Temperature
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-10 20:00 EDT
Jae Ho Jeon, Sahng-Kyoon Jerng, Hong Ryeol Na, Seyoung Kwon, Sungkyun Park, Kang Rok Choe, Jun Sung Kim, Sangmin Ji, Taegeun Yoon, Young Jae Song, Dirk Wulferding, Jeong Kim, Hwayong Noh, Seung-Hyun Chun
Imagine three resistors connected in series. Normally when a battery is connected across the center resistor, the side resistors remain silent with no current flow and no voltage across. Nonlocal voltage is the exceptional potential difference observed at the side resistors. Here, we report sub-V level nonlocal voltages at room temperature, from mm-scale devices comprised of nominal Bi2Se3 on YBa2Cu3O7. They also display extremely nonlinear current-voltage characteristics, potential peaks at current contacts, and negative resistances, suggesting the macroscopic electron hydrodynamics as the origin of nonlocal voltages. Similar observations in Bi2Te3 on YBa2Cu3O7 suggest an unprecedented quantum phase in chemically-modified topological insulators. Vanishing differential resistance may find applications in energy saving transport.
Strongly Correlated Electrons (cond-mat.str-el)
Material realization of spinless, covalent-type Dirac semimetals in three dimensions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Yuki Tanaka, Rinsuke Yamada, Manabu Sato, Motoaki Hirayama, Max Hirschberger
Realization of a three-dimensional (3D) analogue of graphene has been a central challenge in topological materials science. Graphene is stabilized by covalent bonding unlike conventional spin-orbit type 3D Dirac semimetals (DSMs). In this study, we demonstrate the material realization of covalent-type 3D DSMs $ R_8$ Co$ X_3$ stabilized by covalent bonding. We observe that the carrier mobility $ \mu$ of Dirac fermions reaches 3,000$ ,\mathrm{cm^2/Vs}$ even in polycrystalline samples, and $ \mu$ increases with the inverse of the Fermi energy, evidencing significant contributions to charge transport from Dirac electrons. $ R_8$ Co$ X_3$ provides a material platform for exploration of Dirac electrons in three dimensions with wide chemical tunability.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
21 pages, 8 figures (including Supplementary Information)
Origin of persistent photoconductivity in surface conducting hydrogenated diamond films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
N. Mohasin Sulthana, K. Ganesan, P.K. Ajikumar
The p-type surface conductivity of hydrogen-terminated diamond (HD) has opened up new possibilities for the development of diamond-based electronic devices. However, the origin of the persistent photoconductivity (PPC) observed in surface-conducting HD remains unclear, an understanding that is crucial for advancing HD-based optoelectronic technologies. In this study, we investigate the underlying mechanism of PPC in surface-conducting HD films. A systematic analysis was performed by tuning the carrier density via partial oxygen termination using an ozonation process. With increasing O-termination, both the decay time and the recombination barrier of photoexcited electron-hole pairs were found to decrease significantly, from 232 to 5 seconds, and from ~ 150 to 54 meV, respectively. Temperature-dependent measurements reveal that PPC in HD is influenced by random local potential fluctuations, which delay the recombination of photoexcited carriers. Furthermore, the observed PPC behavior is closely associated with percolative transport processes within the HD film. Importantly, the dependence of PPC on sheet carrier density is correlated with Coulomb interactions between the two-dimensional hole gas and the surface adsorbate layer. This study offers new insights into the PPC mechanism in surface-conducting HD films, contributing to the broader understanding necessary for the design of advanced diamond-based optoelectronic devices.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
pages, 7 figures
Dia. Relat. Mater. 157, 112589 (2025)
A time-reversal invariant vortex in topological superconductors and gravitational $\mathbb{Z}_2$ topology
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Kazuki Yamamoto, Naoto Kan, Hidenori Fukaya
We study a topological superconductor in the presence of a time-reversal invariant vortex. The eigenmodes of the Bogoliubov-de-Genne (BdG) Hamiltonian show a $ \mathbb{Z}_2$ topology: the time-reversal invariant vortex with odd winding number supports a pair of helical Majorana zero-modes at the vortex and the edge, while there is no such zero-modes when the winding number is even. We find that this $ \mathbb{Z}_2$ structure can be interpreted as an emergent gravitational effect. Identifying the gap function as spatial components of the vielbein in 2 +1-dimensional gravity theory, we can explicitly convert the BdG equation into the Dirac equation coupled to a nontrivial gravitational background. We find that the gravitational curvature is induced at the vortex core, with its total flux quantized in integer multiples of $ \pi$ , reflecting the $ \mathbb{Z}_2$ topological structure. Although the curvature vanishes everywhere except at the vortex core, the fermionic spectrum remains sensitive to the total curvature flux, owing to the gravitational Aharonov-Bohm effect.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Superconductivity (cond-mat.supr-con), High Energy Physics - Lattice (hep-lat), High Energy Physics - Theory (hep-th)
8 pages, 3 figures
Enhanced superconductivity via layer differentiation in trilayer Hubbard model
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-10 20:00 EDT
Motivated by the highest superconducting transition temperature ($ T_c$ ) in multilayer cuprates,we investigated the trilayer Hubbard model by adopting the large-scale dynamical cluster quantum Monte Carlo simulations. Focusing on the systems with higher hole dopings within the two outer layers (OL) than the inner layer (IL), which is believed to be relevant to the realistic multilayer cuprates, our exploration discovered that the IL and OL manifest strong differentiation in a wide range of hole doping combinations. Specifically, the OLs remain metallic while the IL shows a distinct transition from the pseudogap to superconducting state. More importantly, the highest $ T_c$ of the composite trilayer system can be largely enhanced compared to the single layer model and the imbalanced hole dopings between IL and OL is beneficial to the global SC. We further provide strong numerical evidence on the picture that the IL itself can drive the $ d$ -wave superconductivity while the OLs only serve as the charge reservoir. Our investigation provides new insight into the origin of highest $ T_c$ in multilayer cuprates.
Superconductivity (cond-mat.supr-con), Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el)
8 pages, 6 figures and appendix
The quantum Mpemba effect in long-range spin systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-07-10 20:00 EDT
Shion Yamashika, Filiberto Ares
One of the manifestations of the quantum Mpemba effect (QME) is that a tilted ferromagnet exhibits faster restoration of the spin-rotational symmetry after a quantum quench when starting from a larger tilt angle. This phenomenon has recently been observed experimentally in an ion trap that simulates a long-range spin chain. However, the underlying mechanism of the QME in the presence of long-range interactions remains unclear. Using the time-dependent spin-wave theory, we investigate the dynamical restoration of the spin-rotational symmetry and the QME in generic long-range spin systems. We show that quantum fluctuations of the magnetization drive the restoration of symmetry by melting the initial ferromagnetic order and are responsible for the QME. We find that this effect occurs across a wide parameter range in long-range systems, in contrast to its absence in some short-range counterparts.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
6+7 pages, 2+1 figures
Unconventional Magnetism, Sliding Ferroelectricity, and Magneto-Optical Kerr Effects in a Multiferroic Bilayer
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Chen Xinfeng, Ding Ning, Paolo Barone, Carlo Rizza, Shuai Dong, Wei Ren, Paolo G. Radaelli, Gaoyang Gou, Alessandro Stroppa
Antiferromagnetic (AFM) materials offer a promising platform for exploring novel couplings between altermagnetic (AM) spin-splitting and magneto-optical Kerr effect (MOKE), with potential applications in next-generation quantum technologies. In this work, first-principles calculations, symmetry analysis, and kp modeling are employed to demonstrate how interlayer sliding in AFM multiferroic bilayers enables engineering of the electronic, magnetic, and magneto-optical properties. This study reveals an unprecedented dimension-driven AM crossover, where the 2D paraelectric (PE) bilayer exhibits spin-degenerate bands protected by the [C2||Mc] spin-space symmetry, while the 3D counterpart manifests AM spin-splitting along kz not equal to 0 paths. Furthermore, interlayer sliding breaks the Mc symmetry and stabilizes a ferroelectric (FE) state characterized by compensated ferrimagnetism and a Zeeman effect, which produces non-relativistic spin-split bands. In the FE phase, the inclusion of spin-orbit coupling (SOC) lifts accidental degeneracies, creating `alternating’ spin-polarized bands due to the interplay of Zeeman and Rashba effects. Crucially, the spin polarization, ferro-valley polarization, and Kerr angle are simultaneously reversible by switching either interlayer sliding or the Neel vector. These findings highlight the rich coupling between electronic, magnetic, and optical orders in sliding multiferroics, thereby paving the way for ultra-low-power spintronics and optoelectronic devices.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Phase Retrieval of Highly Strained Bragg Coherent Diffraction Patterns using Supervised Convolutional Neural Network
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Matteo Masto, Vincent Favre-Nicolin, Steven Leake, Clement Atlan, Marie-Ingrid Richard, Tobias Schülli, Ewen Bellec
In Bragg Coherent Diffraction Imaging (BCDI), Phase Retrieval of highly strained crystals is often challenging with standard iterative algorithms. This computational obstacle limits the potential of the technique as it precludes the reconstruction of physically interesting highly-strained particles. Here, we propose a novel approach to this problem using a supervised Convolutional Neural Network (CNN) trained on 3D simulated diffraction data to predict the corresponding reciprocal space phase. This method allows to fully exploit the potential of the CNN by mapping functions within the same space and leveraging structural similarities between input and output. The final object is obtained by the inverse Fourier transform of the retrieved complex diffracted amplitude and is then further refined with iterative algorithms. We demonstrate that our model outperforms standard algorithms on highly strained simulated data not included in the training set, as well as on experimental data.
Materials Science (cond-mat.mtrl-sci), Data Analysis, Statistics and Probability (physics.data-an)
Symmetry Analysis of Magnetoelectric Coupling Effect in All Point Groups
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Xinhai Tu, Di Wang, Hanjing Zhou, Songsong Yan, Huimei Liu, Hongjun Xiang, Xiangang Wan
Symmetry analysis provides crucial insights into the magnetoelectric coupling effect in type-II multiferroics. In this Letter, we comprehensively investigate couplings between electric polarization and inhomogeneous magnetization across all 32 crystallographic point groups using a phenomenological Landau theory. Our theory successfully explains the ferroelectric polarizations in all known type-II multiferroics characterized by incommensurate magnetic orders. In addition, we predict 12 promising type-II multiferroic candidates with the highest magnetic transition temperature of 84 K through systematic screening of MAGNDATA database. Furthermore, we find that the collinear spin-sinusoidal texture emerges as a previously unrecognized source of ferroelectric polarization. We also demonstrate that topological ferroelectric vortex states can be induced by ferromagnetic vortex configurations in uniaxial point groups, opening a route to realizing coexisting multiple-vortex states in multiferroics.
Materials Science (cond-mat.mtrl-sci)
Organic Electronic Classifiers for Sensing
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-10 20:00 EDT
This monograph describes nine years of research carried out at the Institute for Electronics, Micro-electronics and Nanotechnologies (IEMN), developed around defining a generic concept for detection, filling a void between metrological sensors and biological senses, sensing an environment’s qualities along with their measurable properties in information generation technologies. The first chapter introduces fundamental notions of recognition for complex environments, such as for their chemistry, for which organic semiconductors can embed two new functionalities in consumer electronics. The second and third chapters mostly summarize contributions to the state-of-the-art literature on these matters: in the second chapter, on studying conducting polymers as both chemical detectors and conductimetric transducers, and the third chapter, on studying electropolymerization sensitivity to conceptualize evolutionary electronics. The fourth chapter presents several results on the conception of several “classifiers” exploiting both functionalities: in tasks aiming at integrating different sensitivities at a very small scale, at broadening sensing devices’ receptive fields based on experience, and at physically engraving the experience data in a sensing hardware. Along with this monograph are also associated four appendices, summarizing different elements related to the context of this research.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Robustness of the flux-free sector of the Kitaev honeycomb against environment
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-10 20:00 EDT
Alexander Sattler, Maria Daghofer
The Kitaev honeycomb model (KHM) consists of spin-$ 1/2$ particles on a honeycomb lattice with direction-dependent Ising-like interactions. It can alternatively be described in terms of non-interacting Majorana fermions, can be solved exactly, and has a quantum spin-liquid ground state. Open boundaries then host Majorana zero modes (MZMs) that are robust against some types of disorder. We analyze the fate of the MZMs when they couple to an environment via a Lindblad master equation. By computing the time evolution of the density matrix, we find that when decoherence occurs, the steady state is mostly the maximally mixed state. Among the few exceptions is a parameter regime that realizes the superconducting Kitaev chain model with periodic boundary conditions. We consistently observe a quantum Zeno effect in the density matrix as well as in the entropy and fidelity, while it is not found in the energy gap of some gapped spin liquids. We thus present a comprehensive overview over MZMs coupled to a spin bath that is relevant to proposals to detect MZMs of Kitaev layers on surfaces using scanning tunneling microscopy (STM).
Strongly Correlated Electrons (cond-mat.str-el)
13 pages, 9 figures
Electric-field-assisted phase switching for crystal phase quantum dot fabrication in GaAs nanowires
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Qiang Yu (1), Khakimjon Saidov (2), Ivan Erofeev (2), Khalil Hassebi (1), Chen Wei (1), Charles Renard (1), Laetitia Vincent (1), Frank Glas (1), Utkur Mirsaidov (2), Federico Panciera (1) ((1) Université Paris-Saclay, CNRS, Centre de Nanosciences et de Nanotechnologies, Palaiseau, France, (2) Centre for BioImaging Sciences, Department of Biological Sciences and Physics, National University of Singapore, Singapore)
The occurrence of several crystal phases within nanostructures of a single material presents both challenges and opportunities. While unintended phase mixing can degrade optoelectronic performances, deliberate control of polytypism enables novel heterostructures with unique quantum properties, crystal phase quantum dots (CPQDs). However, since tailoring the formation of CPQDs is difficult, applications remain scarce. Here, we demonstrate electric-field-driven crystal phase switching in GaAs nanowires during vapor-liquid-solid growth, enabling precise control of crystal phases and creations of CPQDs with monolayer precision. Nanowires are epitaxially grown on custom-made silicon micro-substrates using chemical vapor deposition within an in-situ TEM. Real-time imaging reveals that the electric field switches instantaneously the crystal phase between zinc blende and wurtzite, creating atomically sharp interfaces. Numerical simulations are developed to investigate the impact of the electric field on the catalyst droplet geometry, which largely governs the crystal phase. This constitutes a key progress towards unlocking the potential of CPQDs.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
19 pages, 4 figures. submitted to journal
On the T-linear resistivity of cuprates: theory
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-07-10 20:00 EDT
Charu Dhiman, Raman Sharma, Navinder Singh
By partitioning the electronic system of the optimally doped cuprates in two electronic components: (1) mobile electrons on oxygen sub-lattice; and (2) localized spins on copper sub-lattice, and considering the scattering of mobile electrons (on oxygen sub-lattice) via generation of paramagnons in the localized sub-system (copper spins), we ask what should be the electron-paramagnon coupling matrix element $ M_q$ so that T-linear resistivity results. This ‘reverse engineering approach’ leads to $ |M_q|^2 \sim \frac{1}{q^2+\xi(T)^{-2}}$ . We comment how can such exotic coupling emerge in 2D systems where short range magnetic fluctuations resides. In other words, the role of quantum criticality is found to be crucial. And the T-linear behaviour of resistivity demands that the magnetic correlation length scales as $ \xi(T)\propto\frac{1}{T}$ , which seems to be a reasonable assumption in the quantum critical regime of cuprates (that is, near optimal doping where T-linear resistivity is observed).
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
5 pages, 2 figures
Real-space understanding of electron-phonon coupling in superconducting hydrides
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-10 20:00 EDT
Trinidad Novoa, Raffaello Bianco, Julia Contreras-García, Ion Errea
Electron-phonon coupling is at the origin of conventional superconductivity, enabling the pairing of electrons into Cooper pairs. The electron-phonon matrix elements depend on the electronic eigenstates and, in the standard linear approximation, on the first derivative of the potential felt by the electrons with respect to ionic perturbations. Here, we focus on the derivatives of the potential with a twofold aim: to assess their contribution to the overall coupling and to analyze the limitations of neglecting higher-order derivatives. Several real-space functions are proposed to do the analysis, and are computed for some well-known superconductors. Our results show that, in hydrides, the derivatives of the potential tend to be larger in regions of high electron localization, explaining the success of electronic descriptors previously described to correlate with the critical temperature. The new functions introduced here are able to tell apart structures with similar types of bonding but very different critical temperatures, such as H3S and H3Se Im-3m phases, where electronic descriptors alone fail. Interestingly, our descriptors are capable of easily estimating the impact of higher-order terms in the electron-phonon coupling. In fact, we capture the limitations of the linear approximation expected for PdH, and predict an even more important non-linear behavior in LaH10.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
Force sensing with a graphene nanomechanical resonator coupled to photonic crystal guided resonances
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Heng Lu, Tingting Li, Hui Hu, Fengnan Chen, Ti Sun, Ying Yan, Chinhua Wang, Joel Moser
Achieving optimal force sensitivity with nanomechanical resonators requires the ability to resolve their thermal vibrations. In two-dimensional resonators, this can be done by measuring the energy they absorb while vibrating in an optical standing wave formed between a light source and a mirror. However, the responsivity of this method – the change in optical energy per unit displacement of the resonator – is modest, fundamentally limited by the physics of propagating plane waves. We present simulations showing that replacing the mirror with a photonic crystal supporting guided resonances increases the responsivity of graphene resonators by an order of magnitude. The steep optical energy gradients enable efficient transduction of flexural vibrations using low optical power, thereby reducing heating. Furthermore, the presence of two guided resonances at different wavelengths allows thermal vibrations to be resolved with a high signal-to-noise ratio across a wide range of membrane positions in free space. Our approach provides a simple optical method for implementing ultrasensitive force detection using a graphene nanomechanical resonator.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Investigating the convergence properties of iterative ptychography for atomic-resolution low-dose imaging
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Tamazouzt Chennit, Songge Li, Hoelen L. Lalandec Robert, Christoph Hofer, Nadine J. Schrenker, Liberato Manna, Sara Bals, Timothy J. Pennycook, Jo Verbeeck
This study investigates the convergence properties of a collection of iterative electron ptychography methods, under low electron doses ($ <$ 10$ ^3$ $ e^-/A^2$ ) and gives particular attention to the impact of the user-defined update strengths. We demonstrate that carefully chosen values for this parameter, ideally smaller than those conventionally met in the literature, are essential for achieving accurate reconstructions of the projected electrostatic potential. Using a 4D dataset of a thin hybrid organic-inorganic formamidinium lead bromide (FAPbBr$ _{3}$ ) sample, we show that convergence is in practice achievable only when the update strengths for both the object and probe are relatively small compared to what is found in literature. Additionally we demonstrate that under low electron doses, the reconstructions initial error increases when the update strength coefficients are reduced below a certain threshold emphasizing the existence of critical values beyond which the algorithms are trapped in local minima. These findings highlight the need for carefully optimized reconstruction parameters in iterative ptychography, especially when working with low electron doses, ensuring both effective convergence and correctness of the result.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Instrumentation and Detectors (physics.ins-det)
Quantum Kinetic Anatomy of Electron Angular Momenta Edge Accumulation
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
T. Valet, H. Jaffres, V. Cros, R. Raimondi
Controlling electron’s spin and orbital degrees of freedom has been a major research focus over the past two decades, as it underpins the electrical manipulation of magnetization. Leveraging a recently introduced quantum kinetic theory of multiband systems [T. Valet and R. Raimondi, Phys. Rev. B 111, L041118 (2025)], we outline how the intrinsic angular momenta linear response is partitioned into intraband and interband contributions. Focusing on time reversal and inversion symmetric metals, we show that the spin and orbital Hall currents are purely intraband. We also reveal that the edge densities originate partially, and in the orbital case mostly, from a new interband mechanism. We discuss how this profoundly impacts the interpretation of orbital edge accumulation observations, and has broader implications for our understanding of current induced torques.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Fast Coherent Splitting of Bose-Einstein Condensates
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-10 20:00 EDT
Yevhenii Kuriatnikov, Nikolaus Würkner, Karthikeyan Kumaran, Tiantian Zhang, M. Venkat Ramana, Andreas Kugi, Jörg Schmiedmayer, Andreas Deutschmann-Olek, Maximilian Prüfer
Preparation of non-trivial quantum states without introducing unwanted excitations or decoherence remains a central challenge in utilizing ultracold atomic systems for quantum simulation. We employ optimal control methods to realize fast, coherent splitting of a one-dimensional Bose-Einstein condensate, achieving minimal classical excitations while preserving quantum correlations. Furthermore, we explore two-step protocols in which controlled classical motion is first induced and subsequently suppressed via tailored control sequences. Our experiments highlight the potential of optimal control for quantum state engineering and dynamical control in many-body quantum systems.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
10 pages, 5 figures
Soliton and traveling wave solutions in coupled one-dimensional condensates
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-07-10 20:00 EDT
Zeyu Rao, Xiaoshui Lin, Jingsong He, Guangcan Guo, Ming Gong
Ultracold condensates provide a unique platform for exploring soliton physics. Motivated by the recent experiments realizing the sine-Gordon model in a split one-dimensional (1D) BEC, we demonstrate that this system naturally supports various density and phase solitons. We explore the physics using the bosonization technique, in which the phase and density are conjugate pairs, and determine its effective Language equation and the associated equation of motion. We show that in the presence of asymmetry between the two condensates, new solutions beyond those in the sine-Gordon model emerge. We calculate the traveling wave solutions and soliton solutions in this model and determine their corresponding energy densities analytically. Finally, we discuss the relevance of these solutions to the experiments and discuss their observations. This theory does not rely on the mechanism of quasi-particle excitation, which yields the Lee-Huang-Yang correction in higher dimensions, and is thus much more suitable to describe the physics in 1D systems. Since the physical models have already been realized in experiments, this work opens a new frontier for the realization of various soliton and periodic solutions using two coupled condensates.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph)
Thickness-Dependent Spin Pumping in YIG/W${90}$Ti${10}$ Bilayers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Marielle Hachem, Zeinab Harajli, Samih Isber, Mohammad Haidar
We investigate the spin pumping efficiency in YIG/YIG/W$ _{90}$ Ti$ {10}$ bilayers by measuring the thickness dependence of both the YIG and WTi layers using broadband ferromagnetic resonance (FMR) spectroscopy. The deposition of a 5-nm WTi layer leads to enhanced Gilbert damping in thinner YIG films, indicating efficient spin current injection. From the spin pumping contribution to the damping of the YIG/WTi bilayer, we determine an effective spin mixing conductance of $ 3.3 \times 10^{18}\mathrm{m}^{-2} $ for the 5-nm WTi layer. Further measurements with varying WTi thickness reveal a non-monotonic dependence of spin mixing conductance, peaking at $ 4.2 \times 10^{18}\mathrm{m}^{-2} $ for a 3-nm WTi layer. This behavior is attributed to a structural phase transition from the high-spin–orbit $ \beta $ -phase to the less efficient $ \alpha $ -phase in thicker WTi layers. Furthermore, comparative analysis with YIG/W bilayers shows that Ti doping significantly reduces $ g^{\uparrow\downarrow}{\mathrm{eff}} $ . These findings highlight the critical role of alloy composition and structural phase in tuning spin transport for spintronic applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Applied Physics (physics.app-ph)
Robust Wannierization including magnetization and spin-orbit coupling via projectability disentanglement
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Yuhao Jiang, Junfeng Qiao, Nataliya Paulish, Weisheng Zhao, Nicola Marzari, Giovanni Pizzi
Maximally-localized Wannier functions (MLWFs) are widely employed as an essential tool for calculating the physical properties of materials due to their localized nature and computational efficiency. Projectability-disentangled Wannier functions (PDWFs) have recently emerged as a reliable and efficient approach for automatically constructing MLWFs that span both occupied and lowest unoccupied bands. Here, we extend the applicability of PDWFs to magnetic systems and/or those including spin-orbit coupling, and implement such extensions in automated workflows. Furthermore, we enhance the robustness and reliability of constructing PDWFs by defining an extended protocol that automatically expands the projectors manifold, when required, by introducing additional appropriate hydrogenic atomic orbitals. We benchmark our extended protocol on a set of 200 chemically diverse materials, as well as on the 40 systems with the largest band distance obtained with the standard PDWF approach, showing that on our test set the present approach delivers a 100% success rate in obtaining accurate Wannier-function interpolations, i.e., an average band distance below 15 meV between the DFT and Wannier-interpolated bands, up to 2 eV above the Fermi level.
Materials Science (cond-mat.mtrl-sci)
Discovery of High-Temperature Charge Order and Time-Reversal Symmetry-Breaking in the Kagome Superconductor YRu3Si2
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-10 20:00 EDT
P. Kràl, J.N. Graham, V. Sazgari, I. Plokhikh, A. Lukovkina, O. Gerguri, I. Bialo, A. Doll, L. Martinelli, J. Oppliger, S.S. Islam, K. Wang, M. Salamin, H. Luetkens, R. Khasanov, M.v. Zimmermann, J.-X. Yin, Ziqiang Wang, J. Chang, B. Monserrat, D. Gawryluk, F.O. von Rohr, S.-W. Kim, Z. Guguchia
The identification of high-temperature unconventional charge order and superconductivity in kagome quantum materials is pivotal for deepening our understanding of geometrically frustrated and correlated electron systems, and for harnessing their exotic properties in future quantum technologies. Here, we report the discovery of a remarkably rich phase diagram in the kagome superconductor YRu$ {3}$ Si$ {2}$ , uncovered through a unique combination of muon spin rotation ($ {\mu}$ SR), magnetotransport, X-ray diffraction (XRD), and density functional theory (DFT) calculations. Our study reveals the emergence of a charge-ordered state with a propagation vector of (1/2, 0, 0), setting a record onset temperature of 800 K for such an order in a kagome system and for quantum materials more broadly. In addition, we observe time-reversal symmetry (TRS) breaking below $ T{2}^{\ast}$ $ {\simeq}$ 25 K and field-induced magnetism below $ T{1}^{\ast}$ $ {\simeq}$ 90 K, indicating the presence of a hidden magnetic state. These transitions are mirrored in the magnetoresistance data, which show a clear onset at $ {\sim}$ $ T_{1}^{\ast}$ and a pronounced increase below $ {\sim}$ $ T_{2}^{\ast}$ , ultimately reaching a maximum magnetoresistance of 45% . Band structure calculations identify two van Hove singularities (VHSs) near the Fermi level, one of which resides within a flat band, suggesting a strong interplay between electronic correlations and emergent orders. At low temperatures, we find bulk superconductivity below $ T_{\mathrm{c}}$ = 3.4 K, characterized by a pairing symmetry with either two isotropic full gaps or an anisotropic nodeless gap. Together, our findings point to a coexistence of high-temperature charge order, tunable magnetism, and multigap superconductivity in YRu$ _{3}$ Si$ _{2}$ , positioning it as a compelling platform for exploring correlated kagome physics.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
13 pages, 7 Figures
Self-induced Floquet states via three-wave processes in synthetic antiferromagnets
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
We present a mechanism for self-induced Floquet states involving acoustic and optical modes in synthetic antiferromagnets. By driving optical modes off-resonantly with radiofrequency fields in the canted antiferromagnetic state, limit cycles arising from the predator-prey dynamics of the acoustic and optical mode populations can appear. The cyclic growth and decay of these mode populations induce a time-periodic modulation of the canted state, which subsequently generates Floquet states. These states appear as a rich frequency comb in the power spectrum of magnetization oscillations.
Materials Science (cond-mat.mtrl-sci)
Anisotropy-Driven Anomalous Inverse Orbital Hall Effect in Fe Films
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
E. Santos, U. Borges, J. L. Costa, J. B. S. Mendes, A. Azevedo
This study investigates the anomalous orbital effects in iron (Fe) films with strong uniaxial anisotropy, highlighting the interactions between spin and orbital currents. Using heterogeneous YIG/Fe and YIG/Pt/Fe structures, fabricated by oblique deposition in a magnetic field, spin pumping ferromagnetic resonance (SP-FMR) measurements were performed. It was observed that the uniaxial anisotropy enables the emergence of spin-to-charge (AISHE) and orbital-to-charge (AIOHE) conversion signals in out-of-plane configurations, where the spin polarization is parallel to the direction of the spin current. Experimental analysis revealed that orbital dynamics, mediated by orbital Hall conductivity, are more prominent in Fe films due to the low spin-orbit interaction (SOC) and high orbital response. These findings provide fundamental insights for the advancement of orbitronics devices, indicating the potential for controlling orbital and spin currents through magnetic and anisotropic parameters.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
6 pages, 5 figures, 3 tables
Excess quasiparticles and their dynamics in the presence of subgap states
New Submission | Superconductivity (cond-mat.supr-con) | 2025-07-10 20:00 EDT
Material inhomogeneities in a superconductor generically lead to broadening of the density of states and to subgap states. The latter are associated with spatial fluctuations of the gap in which quasiparticles can be trapped. Recombination between such localized quasiparticles is hindered by their spatial separation and hence their density could be higher than expectations based on the recombination between mobile quasiparticles. We show here that the recombination between localized and mobile excitations can be efficient at limiting the quasiparticle density. We comment on the significance of our findings for devices such as superconducting resonators and qubits. We find that for typical aluminum devices, the subgap states do not significantly influence the quasiparticle density.
Superconductivity (cond-mat.supr-con), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 3 figures
Analytic toolkit for the Anderson model with arbitrary disorder
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-07-10 20:00 EDT
The Anderson model in one dimension is a quantum particle on a discrete chain of sites with nearest-neighbor hopping and random on-site potentials. It is a progenitor of many further models of disordered systems, and it has spurred numerous developments in diverse branches of physics. The literature is silent, however, on practical analytic tools for computing the density-of-states of this model when the distribution of the on-site potentials is arbitrary. Here, supersymmetry-based techniques are employed to give an explicit linear integral equation whose solutions control the density-of-states. The output of this analytic procedure is in perfect agreement with numerical sampling. By Thouless formula, these results immediately provide analytic control over the localization length.
Disordered Systems and Neural Networks (cond-mat.dis-nn), High Energy Physics - Theory (hep-th), Mathematical Physics (math-ph), Probability (math.PR)
Denjoy’s anachronistic topological viewpoint on Aubry transition
New Submission | Other Condensed Matter (cond-mat.other) | 2025-07-10 20:00 EDT
O. Cépas, G. Masbaum, P. Quémerais
The Aubry transition is a phase transition between two types of incommensurate states, originally described as a transition by ``breaking of analyticity’’. Here we present Denjoy’s (anachronistic) viewpoint, who almost hundred years ago described certain mathematical properties of circle homeomorphisms with irrational rotation numbers. The connection between the two lies in the existence of a change of variables from the incommensurate ground state variables to new simple phase variables that rotate by a constant irrational angle. This confers a cyclic order, an essential property of models with the Aubry transition. Denjoy’s description indicates that there are two types of cyclic order, distinguished by the regular or singular nature of the change of variables or, in mathematical terms, by the distinction between topological conjugacy versus semiconjugacy. This allows rephrasing the breaking of analyticity as a breaking of topological conjugacy. We illustrate this description with numerical calculations on the Frenkel-Kontorova model.
Other Condensed Matter (cond-mat.other)
10 pages, 8 figures
Machine-Learned Force Fields for Lattice Dynamics at Coupled-Cluster Level Accuracy
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Sita Schönbauer, Johanna P. Carbone, Andreas Grüneis
We investigate Machine-Learned Force Fields (MLFFs) trained on approximate Density Functional Theory (DFT) and Coupled Cluster (CC) level potential energy surfaces for the carbon diamond and lithium hydride solids. We assess the accuracy and precision of the MLFFs by calculating phonon dispersions and vibrational densities of states (VDOS) that are compared to experiment and reference ab initio results. To overcome limitations from long-range effects and the lack of atomic forces in the CC training data, a delta-learning approach based on the difference between CC and DFT results is explored. Compared to DFT, MLFFs trained on CC theory yield higher vibrational frequencies for optical modes, agreeing better with experiment. Furthermore, the MLFFs are used to estimate anharmonic effects on the VDOS of lithium hydride at the level of CC theory.
Materials Science (cond-mat.mtrl-sci), Machine Learning (cs.LG), Computational Physics (physics.comp-ph)
22 pages, 12 figures
Photogalvanic effect in hydrodynamic flows of nonreciprocal electron liquids
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
E. Kirkinis, L. Bonds, A. Levchenko, A. V. Andreev
We study nonlinear hydrodynamic electron transport driven by an AC electric field. In noncentrosymmetric conductors with broken time-reversal (TR) symmetry the nonlinear flow of such liquids is nonreciprocal, giving rise to a DC current $ I^{DC}$ that is quadratic in the amplitude of the AC electric field. This is the hydrodynamic analogue of the linear photogalvanic effect (PGE), which arises in bulk noncentrosymmetric materials with broken TR symmetry. The magnitude of $ I^{DC}$ depends on both the properties of the electron fluid and the geometry of the flow, and may be characterized by two dimensionless parameters: the nonreciprocity number $ \mathcal{N}$ , and the frequency-dependent vibrational number $ \mathcal{R}$ . Due to nonlocality of hydrodynamic transport, at low frequencies of the AC drive, $ I^{DC}$ is super-extensive. The AC component of the electric current is likewise strongly affected by nonreciprocity: the hysteretic current-voltage dependence becomes skewed, which can be interpreted in terms of nonreciprocity of the memory retention time.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 8 figures
3D atomic structure determination with ultrashort-pulse MeV electron diffraction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Vincent Hennicke (1), Max Hachmann (2), Paul Benjamin Klar (3), Patrick Y.A. Reinke (1), Tim Pakendorf (1), Jan Meyer (1), Hossein Delsim-Hashemi (2), Miriam Barthelmess (1), Sreevidya Thekku Veedu (1), Pontus Fischer (1), Ana C. Rodrigues (1), Arlinda Qelaj (2), Juna Wernsmann (2), Francois Lemery (2), Sebastian Günther (1), Sven Falke (1), Erik Fröjd (4), Aldo Mozzanica (4), Lukas Palatinus (5), Kai Rossnagel (6 and 7), Bernd Schmitt (4), Henry N. Chapman (1, 8 and 9), Wim Leemans (2), Klaus Flöttmann (2), Alke Meents (1) ((1) Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany, (2) Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany, (3) Faculty of Geosciences and MAPEX Center for Materials and Processes, University of Bremen, Bremen, Germany, (4) Paul-Scherrer Institut, Villigen, Switzerland, (5) Institute of Physics of the Czech Academy of Sciences, Prague, Czechia, (6) Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Kiel, Germany, (7) Ruprecht Haensel Laboratory, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany, (8) The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany, (9) Department of Physics, University of Hamburg, Hamburg, Germany.)
Understanding structure at the atomic scale is fundamental for the development of materials with improved properties. Compared to other probes providing atomic resolution, electrons offer the strongest interaction in combination with minimal radiation damage. Here, we report the successful implementation of MeV electron diffraction for ab initio 3D structure determination at atomic resolution. Using ultrashort electron pulses from the REGAE accelerator, we obtained high-quality diffraction data from muscovite and $ 1T-TaS_2$ , enabling structure refinements according to the dynamical scattering theory and the accurate determination of hydrogen atom positions. The increased penetration depth of MeV electrons allows for structure determination from samples significantly thicker than those typically applicable in electron diffraction. These findings establish MeV electron diffraction as a viable approach for investigating a broad range of materials, including nanostructures and radiation-sensitive compounds, and open up new opportunities for in-situ and time-resolved experiments.
Materials Science (cond-mat.mtrl-sci), Accelerator Physics (physics.acc-ph)
44 pages, 4 (plus 12 supplementary) figures, 8 supplementary tables; High-energy MeV electron diffraction enables structure determinations from considerably thicker samples than currently possible
Reversible Modification of Rashba States in Topological Insulators at Room Temperature by Edge Functionalization
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Wonhee Ko, Seoung-Hun Kang, Qiangsheng Lu, An-Hsi Chen, Gyula Eres, Ho Nyung Lee, Young-Kyun Kwon, Robert G. Moore, Mina Yoon, Matthew Brahlek
Quantum materials with novel spin textures from strong spin-orbit coupling (SOC) are essential components for a wide array of proposed spintronic devices. Topological insulators have necessary strong SOC that imposes a unique spin texture on topological states and Rashba states that arise on the boundary, but there is no established methodology to control the spin texture reversibly. Here, we demonstrate that functionalizing Bi2Se3 films by altering the step-edge termination directly changes the strength of SOC and thereby modifies the Rashba strength of 1D edge states. Scanning tunneling microscopy/spectroscopy shows that these Rashba edge states arise and subsequently vanish through the Se functionalization and reduction process of the step edges. The observations are corroborated by density functional theory calculations, which show that a subtle chemical change of edge termination fundamentally alters the underlying electronic structure. Importantly, we experimentally demonstrated fully reversible and repeatable switching of Rashba edge states across multiple cycles at room temperature. The results imply Se functionalization as a practical method to control SOC and spin texture of quantum states in topological insulators.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Ultrafast and reliable domain-wall and skyrmion logic in a chirally coupled ferrimagnet
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Yifei Ma, Dihua Wu, Fengbo Yan, Xiaoxiao Fang, Peixin Qin, Leran Wang, Li Liu, Laichuan Shen, Zhiqi Liu, Wenyun Yang, Jie Zhang, Yan Zhou, Feng Luo, Jinbo Yang, Hyunsoo Yang, Kaiming Cai, Shuai Ning, Zhaochu Luo
Unlocking the spin degree of freedom in addition to the electron’s charge, spin-based logic offers an in-memory computing architecture beyond-CMOS technology. Here, we encode information into chiral spin textures (e.g., chiral domain-wall and skyrmion) and achieve an ultrafast and reliable all-electrical logic by exploiting the Dzyaloshinskii-Moriya interaction-induced chiral coupling. Taking advantage of fast spin dynamics in antiferromagnetically coupled systems, we achieved a fast domain-wall motion passing through the logic gate, exceeding 1 kilometre per second, yielding an operation time of 50 picoseconds for a 50 nanometres-long logic gate. Furthermore, we present a fast logic operation with skyrmion bubbles in a racetrack that exhibits a topologically protected computation scheme. Our work demonstrates a viable approach for advanced microchips with high operation frequency and ultralow power consumption, paving the way for next-generation computing technologies.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Compressibility of Confined Fluids from Volume Fluctuations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-07-10 20:00 EDT
Jason Ogbebor, Santiago A. Flores Roman, Geordy Jomon, Gennady Y. Gor
When fluids are confined in nanopores, many of their properties deviate from bulk. These include bulk modulus, or compressibility, which determines the mechanical properties of fluid-saturated porous solids. Such properties are of importance for exploration and recovery of coal-bed methane and shale gas. We developed a new molecular simulation method for calculating compressibility of confined fluids, and applied it to methane in carbon nanopores. The method is based on volume fluctuations in the isothermal-isobaric ensemble, made possible through integrated potentials. Our method is one order of magnitude faster than the Monte Carlo approach, and allows calculations for pore sizes up to 100 nm. Our simulations predicted an increase in the fluid bulk modulus by a factor of 4 in 3 nm slit pores, and showed a gradual decrease with the increase of the pore size, so that at 100 nm, the deviation from the bulk is less than 5%.
Soft Condensed Matter (cond-mat.soft), Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph), Geophysics (physics.geo-ph)
12 pages + additional 10 pages of Supplemental Material
Emergent Multiferroic Altermagnets and Spin Control via Noncollinear Molecular Polarization
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-07-10 20:00 EDT
Ziye Zhu, Yuntian Liu, Xunkai Duan, Jiayong Zhang, Bowen Hao, Su-Huai Wei, Igor Zutic, Tong Zhou
Altermagnets, with spin splitting and vanishing magnetization, have been attributed to many fascinating phenomena and potential applications. In particular, integrating ferroelectricity with altermagnetism to enable magnetoelectric coupling and electric control of spin has drawn significant attention. However, its experimental realization and precise spin manipulation remain elusive. Here, by focusing on molecular ferroelectrics, the first discovered ferroelectrics renowned for their highly controllable molecular polarizations and structural flexibility, we reveal that these obstacles can be removed by an emergent multiferroic altermagnets with tunable spin polarization in a large class of fabricated organic materials. Using a symmetry-based design and a tight-binding model, we uncover the underlying mechanism of such molecular ferroelectric altermagnets and demonstrate how noncollinear molecular polarization can switch the spin polarization on and off and even reverse its sign. From the first-principles calculations, we verify the feasibility of these materials in a series of well-established hybrid organic-inorganic perovskites and metal-organic frameworks. Our findings bridge molecular ferroelectrics and altermagnetic spintronics, highlighting an unexplored potential of multifunctional organic multiferroics.
Materials Science (cond-mat.mtrl-sci)
7 pages, 4 figures
Exciton transport driven by spin excitations in an antiferromagnet
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-07-10 20:00 EDT
Florian Dirnberger, Sophia Terres, Zakhar A. Iakovlev, Kseniia Mosina, Zdenek Sofer, Akashdeep Kamra, Mikhail M. Glazov, Alexey Chernikov
A new class of optical quasiparticles called magnetic excitons recently emerged in magnetic van der Waals materials. Akin to the highly effective strategies developed for electrons, the strong interactions of these excitons with the spin degree of freedom may provide innovative solutions for long-standing challenges in optics, such as steering the flow of energy and information. Here, we demonstrate transport of excitons by spin excitations in the van der Waals antiferromagnetic semiconductor CrSBr. Key results of our study are the observations of ultrafast, nearly isotropic exciton propagation substantially enhanced at the Neel temperature, transient contraction and expansion of the exciton clouds at low temperatures, as well as superdiffusive behavior in bilayer samples. These signatures largely defy description by commonly known exciton transport mechanisms and are related to the currents of incoherent magnons induced by laser excitation instead. We propose that the drag forces exerted by these currents can effectively imprint characteristic properties of spin excitations onto the motion of excitons. The universal nature of the underlying exciton-magnon scattering promises driving of excitons by magnons in other magnetic semiconductors and even in non-magnetic materials by proximity in heterostructures, merging the rich physics of magneto-transport with optics and photonics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
12 pages, 4 main figures