CMP Journal 2025-08-21
Statistics
Nature Physics: 1
Science: 18
Physical Review Letters: 3
Physical Review X: 1
arXiv: 54
Nature Physics
Universal quantum gate set for Gottesman-Kitaev-Preskill logical qubits
Original Paper | Quantum information | 2025-08-20 20:00 EDT
V. G. Matsos, C. H. Valahu, M. J. Millican, T. Navickas, X. C. Kolesnikow, M. J. Biercuk, T. R. Tan
Conventional approaches towards creating a large-scale, fault-tolerant quantum computer require an error correction scheme that uses multiple physical qubits to encode one logical qubit of protected quantum information. A key limiting factor in realizing error-corrected quantum information processing is the large ratio of physical-to-logical qubits required by many error correction codes, outstripping the size of near-term devices. The Gottesman-Kitaev-Preskill (GKP) code offers hardware efficiency at the cost of increased encoding complexity by encoding a logical qubit into a single quantum harmonic oscillator. Building on earlier demonstrations of GKP-encoded operations, we realize an entangling gate on GKP logical qubits. Our experiments use an optimal control strategy that deterministically implements a universal set of energy-preserving logical gates on finite-energy GKP states encoded in the mechanical motions of a trapped ion. We also directly generate a GKP Bell state starting from vacuum. Our approach is compatible with existing hardware architectures, demonstrating the potential for optimal control techniques with advanced encoding schemes to accelerate the path towards large-scale fault-tolerant quantum information processing.
Quantum information, Qubits
Science
The MUC19 gene: An evolutionary history of recurrent introgression and natural selection
Research Article | Archaic hominins | 2025-08-21 03:00 EDT
Fernando A. Villanea, David Peede, Eli J. Kaufman, Valeria Añorve-Garibay, Elizabeth T. Chevy, Viridiana Villa-Islas, Kelsey E. Witt, Roberta Zeloni, Davide Marnetto, Priya Moorjani, Flora Jay, Paul N. Valdmanis, María C. Ávila-Arcos, Emilia Huerta-Sánchez
We study the gene MUC19, for which some modern humans carry a Denisovan-like haplotype. MUC19 is a mucin, a glycoprotein that forms gels with various biological functions. We find diagnostic variants for the Denisovan-like MUC19 haplotype at high frequencies in admixed American individuals and at highest frequency in 23 ancient Indigenous American individuals, all pre-dating population admixture with Europeans and Africans. We find that the Denisovan-like MUC19 haplotype is under positive selection and carries a higher copy number of a 30-base-pair variable number tandem repeat, and that copy numbers of this repeat are exceedingly high in admixed American populations. Finally, we find that some Neanderthals carry the Denisovan-like MUC19 haplotype, and that it was likely introgressed into modern human populations through Neanderthal introgression rather than Denisovan introgression.
Fitness benefits of genetic rescue despite chromosomal differences in an endangered pocket mouse
Research Article | Conservation genetics | 2025-08-21 03:00 EDT
Aryn P. Wilder, Debra M. Shier, Shauna N. D. King, Olga Dudchenko, Erik R. Funk, Ann Misuraca, Marlys L. Houck, William B. Miller, Caitlin J. Curry, Julie Fronczek, Ruqayya Khan, David Weisz, Robert N. Fisher, Erez Lieberman Aiden, Oliver A. Ryder, Cynthia C. Steiner
Two-thirds of Earth’s species have undergone population declines, leaving many vulnerable to genomic erosion and inbreeding depression. Genetic rescue can boost the fitness of small populations, but perceived risks of outbreeding depression can limit its use. We quantified these trade-offs in hundreds of endangered Pacific pocket mice (Perognathus longimembris pacificus) by combining whole-genome sequences with fitness data. The impacts of genomic erosion in remnant populations were reversed in an admixed breeding program, suggesting the potential benefits of genetic rescue. However, differences in chromosome numbers increase the risk of genetic incompatibilities. Fitness analyses suggested that although admixed karyotypes may have reduced fertility, non-admixed mice with low heterozygosity and high genetic load had even lower fitness, pointing to a greater risk of extinction if populations remain isolated.
Electrical coherent driving of chiral antiferromagnet
Research Article | Spintronics | 2025-08-21 03:00 EDT
Yutaro Takeuchi, Yuma Sato, Yuta Yamane, Ju-Young Yoon, Yukinori Kanno, Tomohiro Uchimura, K. Vihanga De Zoysa, Jiahao Han, Shun Kanai, Jun’ichi Ieda, Hideo Ohno, Shunsuke Fukami
Electric current driving of antiferromagnetic states at radio or higher frequencies remains challenging to achieve. In this study, we report all-electrical, gigahertz-range coherent driving of chiral antiferromagnet manganese-tin (Mn3Sn) nanodot samples. High coherence in multiple trials and threshold current insensitive to pulse width, in contrast to results observed with ferromagnets, were achieved in subnanosecond range, allowing 1000/1000 switching by 0.1-nanosecond pulses at zero field. These features are attributed to the inertial nature of antiferromagnetic excitations. Our study highlights the potential of antiferromagnetic spintronics to combine high speed and high efficiency in magnetic device operations.
Universal coarsening in a homogeneous two-dimensional Bose gas
Research Article | Quantum simulation | 2025-08-21 03:00 EDT
Martin Gazo, Andrey Karailiev, Tanish Satoor, Christoph Eigen, Maciej Gałka, Zoran Hadzibabic
Coarsening of an isolated far-from-equilibrium quantum system is a paradigmatic many-body phenomenon, relevant from subnuclear to cosmological length scales and predicted to feature universal dynamic scaling. Here, we observed universal scaling in the coarsening of a homogeneous two-dimensional Bose gas, with exponents that match analytical predictions. For different initial states, we reveal universal scaling in the experimentally accessible finite-time dynamics by elucidating and accounting for the initial-state-dependent prescaling effects. The methods we introduce allow direct comparison between cold-atom experiments and nonequilibrium field theory and are applicable to any study of universality far from equilibrium.
The quantum metric of electrons with spin-momentum locking
Research Article | Quantum matter | 2025-08-21 03:00 EDT
Giacomo Sala, Maria Teresa Mercaldo, Klevis Domi, Stefano Gariglio, Mario Cuoco, Carmine Ortix, Andrea D. Caviglia
Quantum materials are characterized by electromagnetic responses intrinsically linked to the geometry and topology of electronic wavefunctions that are encoded in the quantum metric and Berry curvature. Whereas Berry curvature-mediated transport effects have been identified in several magnetic and nonmagnetic systems, quantum metric-induced transport phenomena remain limited to topological antiferromagnets. Here, we show that spin-momentum locking, a general characteristic of the electronic states at surfaces and interfaces of spin-orbit-coupled materials, leads to a finite quantum metric. This metric activates a nonlinear in-plane magnetoresistance that we measured and electrically controlled in 111-oriented LaAlO3/SrTiO3 interfaces. These findings demonstrate the existence of quantum metric effects in a vast class of materials and enable previously unexplored strategies to design functionalities based on quantum geometry.
Stereo-cell: Spatial enhanced-resolution single-cell sequencing with high-density DNA nanoball-patterned arrays
Research Article | Single-cell analysis | 2025-08-21 03:00 EDT
Sha Liao, Xiaoxi Zhou, Chuanyu Liu, Chang Liu, Shijie Hao, Hongyu Luo, Huan Hou, Qian Liu, Zhe Zhang, Liyun Xiao, Yuan Xu, Yaling Huang, Sining Zhou, Xuerong Li, Yang Wang, Lulin Xie, Zhichun Zhou, Shichen Dong, Yiru Wang, Xiaojing Xu, Pengcheng Guo, Xiumei Lin, Jiajie Lei, Qiaoling Wang, Yuxin Gong, Jiaming Cheng, Zixin Yuan, Yongqing Yang, Zhi Huang, Shenglong Li, Yuhui Zheng, Shichen Yang, Xin Huang, Weiqing Liu, Mei Li, Zhonghan Deng, Xinyu Yang, Jianhua Yin, Yingjie Luo, Yiwei Lai, Yue Yuan, Mengnan Cheng, Bo Wang, Jiansong Ji, Miguel A. Esteban, Yuxiang Li, Ying Gu, Yijun Ruan, Liang Chen, Xiangdong Wang, Jun Xie, Jian Wang, Longqi Liu, Ao Chen, Xun Xu
Single-cell sequencing technologies have advanced our understanding of cellular heterogeneity and biological complexity. However, existing methods face limitations in throughput, capture uniformity, cell size flexibility, and technical extensibility. We present Stereo-cell, a spatial enhanced-resolution single-cell sequencing platform based on high-density DNA nanoball (DNB)-patterned arrays, which enables scalable and unbiased cell capture at a wide input range and supports high-fidelity transcriptome profiling. Stereo-cell further allows integration with imaging-based modalities and multiomics strategies, including immunofluorescence and epitope profiling. This platform is also compatible with profiling extracellular vesicles, microstructures, and large cells, whereas its spatial resolution facilitates in situ analysis of cell-cell interactions, cellular microenvironments, and subcellular transcript localization. Together, Stereo-cell provides a flexible framework for expanding single-cell research applications.
Recent evolution of the developing human intestine affects metabolic and barrier functions
Research Article | Evolution | 2025-08-21 03:00 EDT
Qianhui Yu, Umut Kilik, Stefano Secchia, Lukas Adam, Yu-Hwai Tsai, Christiana Fauci, Jasper Janssens, Charlie J. Childs, Katherine D. Walton, Rubén López-Sandoval, Angeline Wu, Marina Almató Bellavista, Sha Huang, Calen A. Steiner, Yannick Throm, Michael James Boyle, Zhisong He, Joep Beumer, Barbara Treutlein, Craig B. Lowe, Jason R. Spence, J. Gray Camp
Diet, microbiota, and other exposures make the intestinal epithelium a nexus for evolutionary change; however, little is known about genomic changes associated with adaptation to a distinctly human environment. In this work, we interrogate the evolution of cell types in the developing human intestine by comparing tissue and organoids from humans, chimpanzees, and mice. We find that recent changes in primates are associated with immune barrier function and lipid and xenobiotic metabolism and that human-specific genetic features affect these functions. Enhancer assays, genetic deletion, and in silico mutagenesis resolve evolutionarily important enhancers of lactase (LCT) and insulin-like growth factor binding protein 2 (IGFBP2). Altogether, we identify the developing human intestinal epithelium as a rapidly evolving system and show that great ape organoids provide insight into human biology.
Mapping early human blood cell differentiation using single-cell proteomics and transcriptomics
Research Article | 2025-08-21 03:00 EDT
Benjamin Furtwängler, Nil Üresin, Sabrina Richter, Mikkel Bruhn Schuster, Despoina Barmpouri, Henrietta Holze, Anne Wenzel, Kirsten Grønbæk, Kim Theilgaard-Mönch, Fabian J. Theis, Erwin M. Schoof, Bo T Porse
Single-cell transcriptomics (scRNA-seq) has facilitated the characterization of cell state heterogeneity and recapitulation of differentiation trajectories. However, the exclusive use of mRNA measurements comes at the risk of missing important biological information. Here we leveraged recent technological advances in single-cell proteomics by Mass Spectrometry (scp-MS) to generate an scp-MS dataset of an in vivo differentiation hierarchy encompassing over 2500 human CD34+ hematopoietic stem and progenitor cells. Through integration with scRNA-seq, we identified proteins that are important for stem cell function, which were not indicated by their mRNA transcripts. Further, we showed that modeling translation dynamics can infer cell progression during differentiation and explain substantially more protein variation from mRNA than linear correlation. Our work offers a framework for single-cell multi-omics studies across biological systems.
Increasing global human exposure to wildland fires despite declining burned area
Research Article | Geography | 2025-08-21 03:00 EDT
Seyd Teymoor Seydi, John T. Abatzoglou, Matthew W. Jones, Crystal A. Kolden, Gabriel Filippelli, Matthew D. Hurteau, Amir AghaKouchak, Charles H. Luce, Chiyuan Miao, Mojtaba Sadegh
Although half of Earth’s population resides in the wildland-urban interface, human exposure to wildland fires remains unquantified. We show that the population directly exposed to wildland fires increased 40% globally from 2002 to 2021 despite a 26% decline in burned area. Increased exposure was mainly driven by enhanced colocation of wildland fires and human settlements, doubling the exposure per unit burned area. We show that population dynamics accounted for 25% of the 440 million human exposures to wildland fires. Although wildfire disasters in North America, Europe, and Oceania have garnered the most attention, 85% of global exposures occurred in Africa. The top 0.01% of fires by intensity accounted for 0.6 and 5% of global exposures and burned area, respectively, warranting enhanced efforts to increase fire resilience in disaster-prone regions.
Ultracompact on-chip spectral shaping using pixelated nano-opto-electro-mechanical gratings
Research Article | Photonics | 2025-08-21 03:00 EDT
Weixin Liu, Siyu Xu, Chengkuo Lee
The ability to shape light spectra dynamically and arbitrarily would revolutionize many photonic systems by offering unparalleled spectral efficiency and network flexibility. However, most existing optical components have rigid spectral functionalities with limited tunability, hindering compact and fast optical spectral shaping. We introduce a pixelated nano-opto-electro-mechanical (NOEM) grating that exploits electromechanically induced symmetry breaking for precise, pixel-level control of grating coupling strength, yielding a miniaturized (~0.007 square millimeters) on-chip spectral shaper. We demonstrate the synthesis of grating pixels for arbitrary spectral responses, and we achieved rapid (<10 nanoseconds), high-contrast (>100 decibels), wavelength-selective switching through collective, nanometer-scale electrostatic perturbations. Our pixelated NOEM grating delivers exceptional spectral manipulation capabilities in an ultracompact, on-chip manner, offering prospects for next-generation optical information networks, computing architectures, and beyond.
Ultrafast elastocapillary fans control agile maneuvering in ripple bugs and robots
Research Article | Biomimicry | 2025-08-21 03:00 EDT
Victor M. Ortega-Jimenez, Dongjin Kim, Sunny Kumar, Changhwan Kim, Je-Sung Koh, Saad Bhamla
Rhagovelia ripple bugs use specialized middle-leg fans with a flat-ribbon architecture to navigate the surfaces of fast-moving streams. We show that the fan’s directional stiffness enables fast, passive elastocapillary morphing, independent of muscle input. This flat-ribbon fan balances collapsibility during leg recovery with rigidity during drag-based propulsion, enabling full-body 96° turns in 50 milliseconds, with forward speeds of up to 120 body lengths per second–on par with fruit fly saccades in air. Drawing from this morphofunctional architecture, we engineered a 1-milligram elastocapillary fan integrated into an insect-scale robot. Experiments with both insects and robots confirmed that self-morphing fans improve thrust, braking, and maneuverability. Our findings link fan microstructure to controlled interfacial propulsion and establish design principles for compact, elastocapillary actuators in agile aquatic microrobots.
Disassembly activates Retron-Septu for antiphage defense
Research Article | Bacterial immunity | 2025-08-21 03:00 EDT
Chen Wang, Anthony D. Rish, Emily G. Armbruster, Jiale Xie, Anna B. Loveland, Zhangfei Shen, Bradley Gu, Andrei A. Korostelev, Joe Pogliano, Tian-Min Fu
Retrons are antiphage defense systems that produce multicopy single-stranded DNA (msDNA) and hold promise for genome engineering. However, the mechanisms of defense remain unclear. The Retron-Septu system integrates retron and Septu antiphage defenses. Cryo-electron microscopy structures reveal asymmetric nucleoprotein complexes comprising a reverse transcriptase, msDNA (a hybrid of msdDNA and msrRNA), and two PtuAB copies. msdDNA and msrRNA are essential for assembling this complex, with msrRNA adopting a conserved lariat-like structure that regulates reverse transcription. Notably, the assembled Retron-Septu complex is inactive, with msdDNA occupying the PtuA DNA binding site. Activation occurs upon disassembly, releasing PtuAB, which degrades single-stranded DNA to restrict phage replication. This “arrest-and-release” mechanism underscores the dynamic regulatory roles of msDNA, advancing our understanding of antiphage defense strategies.
Vegetation changes the trajectory of river bends
Research Article | 2025-08-21 03:00 EDT
Michael Hasson, Alvise Finotello, Alessandro Ielpi, Mathieu G. A. Lapôtre
A primary axiom in geoscience is that the evolution of plants drove global changes in river dynamics. Notably, the apparent sinuosity of rivers, derived from the variance of sediment accretion direction measured in rocks, dramatically increased when land plants evolved, ca. 425 Ma. This led to the hypothesis that the rise of vegetation triggered river meandering. Recent studies of barren, meandering rivers challenge this notion, but the Paleozoic shift in the geometry of river deposits remains unexplained. Here, we suggest that it occurred because vegetation changes how river bends move through space. Using satellite images to monitor river migration, we find that bank vegetation alters the orientation of point bar accretion, resulting in a 62% increase in the inferred variance of flow direction. These results explain why meandering rivers have been under-recognized in pre-vegetation stratigraphy.
Light pollution prolongs avian activity
Research Article | Light pollution | 2025-08-21 03:00 EDT
Brent S. Pease, Neil A. Gilbert
Light pollution disrupts light-dark cues that organisms use as timetables for life. Although studies–typically focusing on individual species–have documented earlier morning onset of bird vocalization in light-polluted landscapes, a synthesis of light pollution effects across species, space, and season is lacking. We used a global acoustic dataset of more than 60 million detections, representing 583 diurnal bird species, to synthesize effects of light pollution on avian vocalization. On average, light pollution prolonged vocal activity by 50 min. Light pollution responses were strongest for species with large eyes, open nests, migratory habits, and large ranges and during the breeding season. Prolonged activity may confer negative, neutral, or positive fitness effects; documenting these fitness effects and curbing light pollution are challenges for 21st-century conservation.
By-product recovery from US metal mines could reduce import reliance for critical minerals
Research Article | 2025-08-21 03:00 EDT
Elizabeth A. Holley, Karlie M. Hadden, Dorit Hammerling, Rod Eggert, D. Erik Spiller, Priscilla P. Nelson
The US has sufficient geological endowment in active metal mines to reduce the nation’s dependence on critical mineral imports. Demand is increasing for cobalt, nickel, rare earth elements, tellurium, germanium, and other materials used in energy production, semiconductors, and defense. This study uses a statistical evaluation of new geochemical datasets to quantify the critical minerals that are mined annually in US ores but go unrecovered. Ninety percent recovery of by-products from existing domestic metal mining operations could meet nearly all US critical mineral needs; one percent recovery would substantially reduce import reliance for most elements evaluated. Policies and technological advancements can enable by-product recovery, which is a resource-efficient approach to critical mineral supply that reduces waste, impact, and geopolitical risk.
Overcoming energy disorder for cavity-enabled energy transfer in vibrational polaritons
Research Article | Chemical physics | 2025-08-21 03:00 EDT
Guoxin Yin, Tianlin Liu, Lizhu Zhang, Tianyu Sheng, Haochuan Mao, Wei Xiong
Energy disorder is ubiquitous in chemistry and physics. It can suppress polariton delocalization by disrupting molecular coherence-limiting polariton-modified properties. We investigated how energy disorders affect vibrational polariton dynamics by probing ultrafast dynamics in 2,6-di-tert-butylphenol in liquids (inhomogeneous) and solids (homogeneous) using two-dimensional infrared spectroscopy and molecular dynamics simulations. In liquids, energy disorder disrupted delocalization, preventing vibrational energy transfer. By contrast, with reduced inhomogeneity, vibrational strong coupling in solids restored delocalization and enabled energy transfer. We established a stringent delocalization criterion, requiring collective coupling strengths exceeding three times inhomogeneous linewidths to sustain polariton coherence. This finding highlights energy disorder’s detrimental effects and outlines strategies to overcome localization–either by minimizing disorder through chemical control or by achieving sufficient couplings using advanced photonic structures.
Dysfunction in primate dorsolateral prefrontal area 46 affects motivation and anxiety
Research Article | Neuroscience | 2025-08-21 03:00 EDT
Christian M. Wood, Rana Banai Tizkar, Martina Fort, Xinhu Zhang, Kevin G. Mulvihill, Naixuan Liao, Gemma J. Cockcroft, Lauren B. McIver, Stephen J. Sawiak, Angela C. Roberts
The dorsolateral prefrontal cortex (dlPFC) is a higher-order brain structure targeted for noninvasive stimulation for treatment-resistant depression. Nonetheless, its causal role in emotion regulation is unknown. We discovered that inactivating dlPFC area 46 in marmosets blunts appetitive motivation and heightens threat reactivity. The effects were asymmetric–dependent on the left hemisphere only–and were mediated through projections to pregenual cingulate area 32. The antidepressant ketamine blocked the appetitive motivational deficits through mechanisms within subcallosal cingulate area 25, an area linked with treatment success in dlPFC noninvasive stimulation. Our data uncover an integrated prefrontal network for area 46 that contributes to positive and negative emotion regulation that may be core to our understanding of symptoms and therapeutic strategies for treatment-resistant depression and anxiety.
LYVAC/PDZD8 is a lysosomal vacuolator
Research Article | Cell biology | 2025-08-21 03:00 EDT
Haoxiang Yang, Jinrui Xun, Yajuan Li, Awishi Mondal, Bo Lv, Simon C. Watkins, Lingyan Shi, Jay Xiaojun Tan
Lysosomal vacuolation is commonly found in many pathophysiological conditions, but its molecular mechanisms and functions remain largely unknown. Here, we show that the endoplasmic reticulum (ER)-anchored lipid transfer protein PDZ domain-containing 8 (PDZD8), which we propose to be renamed as lysosomal vacuolator (LYVAC), is a general mediator of lysosomal vacuolation. Using human cell lines, we found that diverse lysosomal vacuolation inducers converged on lysosomal osmotic stress, triggering LYVAC recruitment through multivalent interactions. Stress-induced lysosomal lipid signaling contributed to both the recruitment and activation of LYVAC. By directly sensing lysosomal phosphatidylserine and cholesterol, the lipid transfer domain of LYVAC mediated directional ER-to-lysosome lipid movement, leading to osmotic membrane expansion of lysosomes. These findings uncover an essential mechanism for lysosomal vacuolation with broad implications in pathophysiology.
Physical Review Letters
First Sub-MeV Dark Matter Search with the QROCODILE Experiment Using Superconducting Nanowire Single-Photon Detectors
Research article | Dark matter | 2025-08-20 06:00 EDT
Laura Baudis, Alexander Bismark, Noah Brugger, Chiara Capelli, Ilya Charaev, Jose Cuenca García, Guy Daniel Hadas, Yonit Hochberg, Judith K. Hohmann, Alexander Kavner, Christian Koos, Artem Kuzmin, Benjamin V. Lehmann, Severin Nägeli, Titus Neupert, Bjoern Penning, Diego Ramírez García, and Andreas Schilling
Superconducting sensors can detect single low-energy photons. Researchers have now used this capability in a dark matter experiment.
Phys. Rev. Lett. 135, 081002 (2025)
Dark matter, Dark matter direct detection, Nanowires, Superconducting devices, Dark matter detectors
Interface Modes in Inspiralling Neutron Stars: A Gravitational-Wave Probe of First-Order Phase Transitions
Research article | Gravitational wave sources | 2025-08-20 06:00 EDT
A. R. Counsell, F. Gittins, N. Andersson, and I. Tews
At the extreme densities in neutron stars, a phase transition to deconfined quark matter is anticipated. Yet masses, radii, and tidal deformabilities offer only indirect measures of a first-order phase transition, requiring many detections to resolve or being ineffective observables if the discontinuity exists at lower densities. We report on a smoking-gun gravitational-wave signature of a first-order transition: the resonant tidal excitation of an interface mode. Using relativistic perturbation theory with an equation-of-state family informed by chiral effective field theory, we show that such a resonance may be detectable with next-generation interferometers and possibly already with LIGO $\mathrm{A}+$ for sufficiently loud events.
Phys. Rev. Lett. 135, 081402 (2025)
Gravitational wave sources, Nuclear matter in neutron stars, Phase transitions, Binary stars, Neutron stars & pulsars
Imaging Valence Electron Rearrangement in a Chemical Reaction Using Hard X-Ray Scattering
Research article | Atomic & molecular structure | 2025-08-20 06:00 EDT
Ian Gabalski et al.
*et al.*Scientists have used ultrashort x-ray pulses to directly observe the motion of electrons driving a chemical reaction.
Phys. Rev. Lett. 135, 083001 (2025)
Atomic & molecular structure, Chemical reactions, Electronic excitation & ionization, Electronic structure of atoms & molecules, Molecular dissociation, Scattering theory
Physical Review X
Multimessenger Search for Exotic Field Emission with a Global Magnetometer Network
Research article | Extensions of scalar sector | 2025-08-20 06:00 EDT
Sami S. Khamis et al.
*et al.*Black hole mergers may emit bursts of unknown particles. A search of data from a global magnetometer network during a gravitational-wave event, while not turning up such signals, sets the first lab-based limits on exotic emissions tied to dark matter.
Phys. Rev. X 15, 031048 (2025)
Extensions of scalar sector, Magnetometry, Quantum networks, Astronomical black holes
arXiv
Microrheology with rotational Brownian motion
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
Passive rotational microrheology (RMR) for evaluating the dynamic modulus (G^\ast) of a suspending fluid through the rotational Brownian motion of a spherical probe particle is validated using direct numerical simulations (DNS) of Brownian motion in a viscoelastic fluid. Two methods of RMR are compared: an inertialess RMR based on the Generalized Stokes–Einstein relation for rotational diffusion (RGSER) and the full RMR based on the generalized Langevin equation for rotation, which accounts for fluid and particle inertia. Our analysis, performed using DNS of the fluctuating Oldroyd-B fluid, reveals that inertialess RMR accurately estimates (G^\ast) for (\omega\lambda \alt 1), but deviates significantly at high frequencies. In contrast, the full RMR improves (G^\ast) estimation accuracy up to the frequency (\omega \approx \tau_{s}^{-1}=\eta_{s}/\rho_{f}a^{2}), where fluid inertia becomes relevant. However, in the ballistic regime ((t \ll \tau_{s})), particle inertia dominates, making accurate (G^\ast) evaluation challenging even with the full RMR. This study clarifies the applicability range of RMR. Additionally, rotational Brownian motion is turned out to be insensitive to periodic boundary conditions, which allows direct application to various mesoscale molecular simulations, including coarse-grained molecular dynamics, dissipative particle dynamics, and fluid dynamics simulations. In conclusion, rotational microrheology offers a promising approach for detailed rheological analysis in complex systems and conditions.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
Physics of Fluids, in press
Mott transition from the non-analyticity of the one-body reduced density-matrix functional
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Zhengqian Cheng, Chris A. Marianetti
One-body reduced density-matrix functional (1RDMF) theory has yielded promising results for small systems such as molecules, but has not addressed quantum phase transitions such as the Mott transition. Here we explicitly execute the constrained search within a variational ansatz to construct a 1RDMF for the multi-orbital Hubbard model with up to seven orbitals in the thermodynamic limit. The variational ansatz is the \mathcal{N}=3 ansatz of the variational discrete action theory (VDAT), which can be exactly evaluated in d=\infty. The resulting 1RDMF exactly encapsulates the \mathcal{N}=3 VDAT results, which accurately captures Mott and Hund physics. We find that non-analytic behavior emerges in our 1RDMF at fixed integer filling, which gives rise to the Mott transition. We explain this behavior by separating the constrained search into multiple stages, illustrating how a nonzero Hund exchange drives the continuous Mott transition to become first-order. Our approach creates a new path forward for constructing an accurate 1RDMF for strongly correlated electron materials.
Strongly Correlated Electrons (cond-mat.str-el)
Matrix Product Operator Constructions for Gauge Theories in the Thermodynamic Limit
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Nicholas Godfrey, Ian P. McCulloch
We present a general method for simulating lattice gauge theories in low dimensions using infinite matrix product states (iMPS). A central challenge in Hamiltonian formulations of gauge theories is the unbounded local Hilbert space associated with gauge degrees of freedom. In one spatial dimension, Gauss’s law permits these gauge fields to be integrated out, yielding an effective Hamiltonian with long-range interactions among matter fields. We construct efficient matrix product operator (MPO) representations of these Hamiltonians directly in the thermodynamic limit. Our formulation naturally includes background fields and $ \theta$ -terms, requiring no modifications to the standard iDMRG algorithm. This provides a broadly applicable framework for 1+1D gauge theories and can be extended to quasi-two-dimensional geometries such as infinite cylinders, where tensor-network methods remain tractable. As a benchmark, we apply our construction to the Schwinger model, reproducing expected features including confinement, string breaking, and the critical behavior at finite mass. Because the method alters only the MPO structure, it can be incorporated with little effort into a wide range of iMPS and infinite-boundary-condition algorithms, opening the way to efficient studies of both equilibrium and non-equilibrium gauge dynamics.
Strongly Correlated Electrons (cond-mat.str-el), High Energy Physics - Lattice (hep-lat), Quantum Physics (quant-ph)
The numerical case for identifying paired quantum Hall phases by their daughters
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Misha Yutushui, Arjun Dey, David F. Mross
Many candidate non-Abelian quantum Hall states are accompanied by nearby `daughter’ states, which are proposed to identify their topological order. Combining exact diagonalization and trial wave functions, we provide numerical evidence that daughter states reliably predict the parent topological phase. In the contexts of bilayer graphene and wide GaAs quantum wells, we show that the same interactions simultaneously stabilize Pfaffian, anti-Pfaffian, and their daughters, while suppressing the Jain states. The competition between Pfaffian and anti-Pfaffian, which is decided by particle-hole symmetry-breaking interactions, can likewise be deduced from their daughters. These findings strongly support the daughter-state-based identification of non-Abelian quantum Hall phases.
Strongly Correlated Electrons (cond-mat.str-el)
The trial wave functions used in this study are available at this https URL, stored in DiagHam-compatible binary format
Average weighted ratio of consecutive level spacings for infinite-dimensional orthogonal random matrices
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-21 20:00 EDT
The onset of quantum ergodicity is often quantified by the average ratio of consecutive level spacings. The reference values for ergodic quantum systems have been obtained numerically from the spectra of large but finite-dimensional random matrices. This work introduces a weighted ratio of consecutive level spacings, having the propery that the average can be computed numerically for random matrices of infinite dimension. A Painlevé differential equation is solved numerically in order to determine this average for infinite-dimensional orthogonal random matrices, thereby providing a reference value for ergodic quantum systems obeying time-reversal symmetry. A Wigner surmise-inspired analytical calculation is found to yield a qualitatively accurate picture for the statistics of high-dimensional random matrices from each of the symmetry classes. For Poissonian level statistics, a significantly different average is found, indicating that the average weighted ratio of consecutive level spacings can be used as a probe for quantum ergodicity.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph)
6 pages, 2 figures
Topologically trivial semiconducting behavior and polaronic effects in antiferromagnetic EuZn$_2$As$_2$ and EuCd$_2$Sb$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Divyanshi Sar, Mingda Gong, Tetiana Romanova, Luka Khizanishvili, Hannah Park, Dariusz Kaczorowski, Wei-Cheng Lee, Pegor Aynajian
The Eu-based EuA$ _2$ X$ _2$ (A = Zn, Cd, In, Sn; X = P, As, Sb) family of compounds has recently attracted significant attention as a promising platform for exploring magnetic topological materials, with several members either predicted or reported to exhibit nontrivial topological properties. We investigate the previously reported topological semimetals, EuZn$ _2$ As$ _2$ and EuCd$ _2$ Sb$ _2$ , using scanning tunneling microscopy and spectroscopy, complemented by various first-principles computational approaches. Through examination of the cleaved surfaces, step-edges, and defect states, we determine the trivial semiconducting behavior in both material systems, with no evidence of topological surface or edge states. These experimental results are consistent with our theoretical analysis revealing the absence of topological band inversion in either system. Our experimental observations also reveal numerous intrinsic defects that trap charge carriers. These defects may facilitate the formation of magnetic polarons, providing a natural explanation for the colossal negative magnetoresistance observed in many of the EuA$ _2$ X$ _2$ material systems.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Non-invertible symmetries out of equilibrium
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Through the study of the Rep($ D_8$ ) non-invertible symmetry, we show how non-invertible symmetries manifest in dynamics. By considering the effect of symmetry preserving disorder, the non-invertible symmetry is shown to give rise to degeneracies in the spectra that can only be completely lifted at orders of perturbation that scale with system size. The eigenstates of disordered Hamiltonians, whose ground state correspond to non-trivial symmetry protected topological (SPT) states, are shown to have either trivial or non-trivial SPT order that are detected as non-zero expectation value of string order-parameters. In contrast, non-trivial SPT order is absent in the eigenstates of trivial SPT Hamiltonians with disorder. The interface between two different SPT phases host edge modes whose dynamics is studied numerically and analytically. The edge mode is shown to oscillate at frequencies related to different effective chain lengths that are weighted by the temperature, becoming an exact zero mode in the limit of zero temperature. A Floquet model with the non-invertible symmetry is constructed whose edge mode is shown to exhibit period-doubled dynamics at low effective-temperatures.
Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
NV-like Defects More Common Than Four-Leaf Clovers: A Perspective on High-Throughput Point Defect Data
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Point defects for quantum technologies is an emerging research area, with the nitrogen-vacancy (NV) center in diamond at the forefront. However, how rare are defects with NV-like properties? In this perspective, I highlight the results of NV-like defects across 17 different materials, revealing that they are more common than finding four-leaf clovers. I also discuss expanding the search criteria to identify other defects relevant to quantum technologies. Utilizing point defect databases will be instrumental in assisting researchers in discovering previously unexplored defects suitable for quantum technologies.
Materials Science (cond-mat.mtrl-sci)
Perspective Article
Engineering and exploiting self-driven domain wall motion in ferrimagnets for neuromorphic computing applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Jeffrey A. Brock, Aleksandr Kurenkov, Aleš Hrabec, Laura J. Heyderman
Magnetic domain wall motion has recently garnered significant interest as a physical mechanism to enable energy-efficient, next-generation brain-inspired computing architectures. However, realizing all behaviors required for neuromorphic computing within standard material systems remains a significant challenge, as these functionalities often rely on competing interactions. Here, we demonstrate how spontaneous domain wall motion in response to locally engineered lateral exchange coupling in transition metal-rare earth ferrimagnets can be leveraged to achieve numerous neuromorphic computing functionalities in devices with minimal complexity. Through experiments and micromagnetic simulations, we show how tuning the feature size, material composition, and chiral interaction strength controls the speed of self-driven domain wall motion. When integrated with spin-orbit torque, this control gives rise to behaviors essential for neuromorphic computing, including leaky integration and passive resetting of artificial neuron potential. These results establish locally engineered ferrimagnets as a tunable, scalable, and straightforward platform for domain wall-based computing architectures.
Materials Science (cond-mat.mtrl-sci)
22 pages, 4 figures, 5 supporting figures
Lattice anharmonicity effects in fluorite oxide single crystals and anomalous increase in phonon lifetime in ceria at elevated temperature
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Amey Khanolkar, Saqeeb Adnan, Md Minaruzzaman, Linu Malakkal, Darren B. Thomson, David B. Turner, J. Matthew Mann, David H. Hurley, Marat Khafizov
We investigate the temperature dependence of the frequency and linewidth of the triply-degenerate T$ _{2g}$ zone-centered optical phonon in flux-grown ceria and hydrothermally-synthesized thoria single crystals from room temperature to 1273 K using Raman spectroscopy. Both crystals exhibit an expected increase in the phonon linewidth with temperature due to enhanced phonon-phonon scattering. However, ceria displays an anomalous linewidth reduction in the temperature range of 1023-1123 K. First-principles phonon linewidth calculations considering cubic and quartic phonon interactions within temperature-independent phonon dispersion fail to describe this anomaly. A parameterization of the temperature-dependent second order interatomic force constants based on previously reported phonon dispersion measured at room and high temperatures, predicts a deviation from the monotonic linewidth increase, albeit at temperatures lower than those observed experimentally for ceria. The qualitative agreement in the trend of temperature-dependent linewidth suggests that lattice anharmonicity-induced phonon renormalization plays a role in phonon lifetime. Specifically, a change in the overlap between softened acoustic and optical branches in the dispersion curve reduces the available phonon scattering phase space of the Raman active mode at the zone center, leading to an increased phonon lifetime within a narrow temperature interval. These findings provide new insights into higher-order anharmonic interactions in ceria and thoria, motivating further investigations into the role of anharmonicity-induced phonon renormalization on phonon lifetimes at high temperatures.
Materials Science (cond-mat.mtrl-sci)
Real-space first-principles approach to orbitronic phenomena in metallic multilayers
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Ramon Cardias, Hugo U. R. Strand, Anders Bergman, A. B. Klautau, Tatiana G. Rappoport
We develop a real-space first-principles method based on density functional theory to investigate orbitronic phenomena in complex materials. Using the Real-Space Linear Muffin-Tin Orbital method within the Atomic Sphere Approximation (RS-LMTO-ASA) combined with a Chebyshev polynomial expansion of the Green’s functions, we compute orbital (spin) Hall transport and orbital (spin) accumulation directly in real space. The approach scales linearly with system size and naturally incorporates disorder, finite-size effects, and interface roughness. We apply the method to transition-metal-based heterostructures and demonstrate the emergence of substantial orbital (spin) accumulation, even in centrosymmetric systems. Our methodology provides a scalable and flexible framework for realistic simulations of orbital transport phenomena in complex heterostructures.
Materials Science (cond-mat.mtrl-sci)
12 pages, 5 figures
Role of electron-electron interactions in $M$-valley twisted transition metal dichalcogenides
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
Christophe De Beule, Liangtao Peng, E. J. Mele, Shaffique Adam
We investigate the role of long-range Coulomb interactions in $ M$ -valley moiré systems using the self-consistent Hartree-Fock approximation. This platform was recently proposed [Nature 643, 376 (2025) and arXiv:2411.18828 (2024)] as a new class of experimentally realizable moiré materials using twisted transition metal dichalcogenides homobilayers with the 1T structure. While these seminal studies considered the noninteracting theory without an interlayer bias due to an electric displacement field, this work shows that both electron-electron interactions at finite doping and an interlayer bias strongly modify the moiré bands. For small twist angles, the density of states as a function of filling and interlayer bias shows qualitatively different behavior for twisting near aligned ($ 0^\circ$ ) and antialigned ($ 60^\circ$ ) stacking. More interestingly, the Van Hove singularity becomes pinned to the Fermi energy over a finite range of doping, an effect known to enhance both superconductivity and strongly correlated states. For aligned stacking this occurs only at zero electric field, while for antialigned stacking this happens both at zero and finite field. Our work demonstrates that correlated states in $ M$ -valley 1TtTMDs can be strongly tuned \textit{in situ} both by applying an electric displacement field and by electron doping.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Machine-learning interatomic potentials achieving CCSD(T) accuracy for van-der-Waals-dominated systems via Δ-learning
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Yuji Ikeda, Axel Forslund, Pranav Kumar, Yongliang Ou, Jong Hyun Jung, Andreas Köhn, Blazej Grabowski
Machine-learning interatomic potentials (MLIPs) enable large-scale atomistic simulations at moderate computational cost while retaining ab initio accuracy. However, most MLIPs are trained on density-functional theory (DFT), which often falls short of chemical accuracy (1 kcal/mol). Conversely, coupled-cluster methods, particularly CCSD(T), which includes single, double, and perturbative triple excitations, are considered the gold standard of computational chemistry but rarely applied to periodic systems due to their huge computational cost. Here we present a $ \Delta$ -learning workflow to produce interatomic potentials with CCSD(T) accuracy for periodic systems including van der Waals (vdW) interactions. The procedure combines a dispersion-corrected tight-binding baseline with an MLIP trained on the differences of the target CCSD(T) energies from the baseline. This $ \Delta$ -learning strategy enables training on compact molecular fragments while preserving transferability. The dispersion interactions are captured by including vdW-bound multimers in the training set; together with the vdW-aware tight-binding baseline, the formally local MLIP attains CCSD(T) accuracy for systems governed by long-range vdW forces. The resulting potential yields root-mean-square energy errors below 0.4 meV/atom on both training and test sets and reproduces electronic total atomization energies, bond lengths, harmonic vibrational frequencies, and inter-molecular interaction energies for benchmark molecular systems. We apply the method to a prototypical quasi-two-dimensional covalent organic framework (COF) composed of carbon and hydrogen. The COF structure, inter-layer binding energies, and hydrogen absorption are analyzed at CCSD(T) accuracy. Overall, the developed $ \Delta$ -learning approach opens a practical route to large-scale atomistic simulations that include vdW interactions with chemical accuracy.
Materials Science (cond-mat.mtrl-sci)
Quadrupole-conserving dynamics in the non-commutative plane
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-21 20:00 EDT
Inspired by ``fracton hydrodynamic” universality classes of dynamics with unusual conservation laws, we present a new dynamical universality class that arises out of local area-preserving dynamics in the non-commutative plane. On this symplectic manifold, the area-preserving spatial symmetry group $ \mathrm{SL}(2,\mathbb{R})\rtimes \mathbb{R}^2$ is a symmetry group compatible with non-trivial many-body dynamics. The conservation laws associated to this symmetry group correspond to the dipole and quadrupole moments of the particles. We study the unusual dynamics of a crystal lattice subject to such symmetries, and argue that the hydrodynamic description of lattice dynamics breaks down due to relevant nonlinearities. Numerical simulations of classical Hamiltonian dynamical systems with this symmetry are largely consistent with a tree-level effective field theory estimate for the endpoint of this instability.
Statistical Mechanics (cond-mat.stat-mech)
18 pages, 6 figures
Modeling of silver transport in cubic SiC: Integrating molecular dynamics, bounds averaging, and uncertainty quantification
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Mohamed AbdulHameed, Khadija Mahbuba, Mahmoud Yaseen, Amr Ibrahim, Daniel Moneghan, Benjamin Beeler
Silver released from TRISO fuel particles can migrate through the SiC layer and deposit on reactor components, posing radiation hazards and operational challenges. Despite numerous proposed mechanisms, the precise pathway of silver transport through intact 3C-SiC remains unresolved. We present a physics-informed model for estimating the effective diffusivity of silver in polycrystalline 3C-SiC. Molecular dynamics (MD) simulations yield diffusivities for {\Sigma 3} and {\Sigma 9} grain boundaries (GBs), while literature values are used for other GB types and the bulk. These are combined using a bounds-averaging approach accounting for distinct GB transport properties. Bayesian inference of experimental data provides credible intervals for effective Arrhenius parameters and reveals a correlation between activation energy and pre-exponential factor. Although the homogenized model captures GB-mediated transport mechanisms, it overpredicts silver diffusivity relative to experiments. To resolve this, a multiplicative correction based on reversible trapping at nano-pores is introduced. It is derived from first principles and is shown to reproduce observed transport behavior. Sensitivity analysis identified trap desorption energy and {\Sigma 9} GB diffusivity as dominant factors influencing Ag transport. The resulting framework provides a mechanistic description of Ag transport suitable for integration into higher-scale fuel performance models.
Materials Science (cond-mat.mtrl-sci)
Modeling oxygen-void interactions in uranium nitride
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Mohamed AbdulHameed, Anton J. Schneider, Benjamin Beeler, Michael W.D. Cooper
Oxygen impurities in uranium nitride (UN) are reported to influence its swelling behavior under irradiation, yet the underlying mechanism remains unknown. In this work, we develop a first-principles model that quantifies the interaction of oxygen with voids and fission gas bubbles in UN, leading to a reduction in surface energy that can promote swelling. The analysis reveals that segregation of substitutional oxygen at surface nitrogen sites is the primary driver of surface energy reduction, $ |\Delta \sigma|$ , while oxygen in surface hollow sites plays a minor and sometimes counteracting role. $ |\Delta \sigma|$ is most pronounced for small cavities ($ R_v$ = 1–10 nm) at intermediate temperatures that coincide with the onset of breakaway swelling in UN. Larger voids require higher temperatures for oxygen adsorption to significantly lower their surface energy. The temperature dependence of $ |\Delta \sigma|$ exhibits three regimes: negligible reduction at low temperatures due to sluggish oxygen diffusion, a maximum at intermediate temperatures where oxygen incorporation is optimal, and a decline at high temperatures due to enhanced bulk solubility. A parametric analysis reveals that $ |\Delta \sigma|$ depends strongly on both oxygen concentration and cavity size, but is largely insensitive to porosity. Our results suggest that oxygen-induced surface energy reduction is essential for reconciling the mechanistic swelling model of UN with experimental observations.
Materials Science (cond-mat.mtrl-sci)
Cavity-mediated multispin interactions and phase transitions in ultracold Fermi gases
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-21 20:00 EDT
Zhen Zheng, Shi-Liang Zhu, Z. D. Wang
The many-body physics of higher-spin systems is expected to host qualitatively new matter phases, but realizing them requires the controllable multispin interactions that can be tuned independently for each spin component. Here we propose a scheme that meets this demand in ultracold Fermi gases. By engineering the atom-cavity coupling, we generate cavity-mediated effective interactions between arbitrary pseudo-spin states. Focusing on the simplest three-spin case, we obtain two independent scattering channels whose strengths and signs can be adjusted separately. The resulting Hamiltonian combines the on-site attraction with the off-site repulsion, and drives a continuous transition from the superfluid to the spin-density-wave phase. The coexistence region is reminiscent of a supersolid, yet the self-organized modulation appears in the spin space of a higher-spin representation, rather than in the density profile. The proposal is reliable to be implemented using the existing techniques of ultracold atoms. Therefore it offers a versatile platform for quantum simulation of higher-spin many-body physics.
Quantum Gases (cond-mat.quant-gas)
8 pages, 4 figures
Single layer clathrane: A potential superconducting two-dimensional (2D) hydrogenated metal borocarbide
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-21 20:00 EDT
Xiaoyu Wang, Warren E. Pickett, Matthew N. Julian, Rohit P. Prasankumar, Eva Zurek
We propose a new family of two-dimensional (2D) metal-borocarbide clathrane superconductors, derived from three-dimensional (3D) MM$ ^\prime$ B$ _6$ C$ _6$ clathrates. First-principles calculations reveal that hydrogen passivation and surface metal decoration stabilize the M$ _2$ M$ ^\prime$ B$ _8$ C$ _8$ H$ _8$ monolayers. These 2D systems exhibit tunable superconductivity governed by hole concentration, structural anisotropy, and electron-phonon coupling. We find that in-plane anisotropy competes with superconductivity, reducing \tc\ despite favorable doping. Biaxial strain mitigates this anisotropy, enhances Fermi surface nesting, and increases \tc\ by an average of 15.5K. For example, the \tc\ of Sr$ _3$ B$ _8$ C$ _8$ H$ _8$ is predicted to increase from 11.3K to 22.2~K with strain engineering. These findings identify 2D clathranes as promising, strain-tunable superconductors and highlight design principles for optimizing low-dimensional superconducting materials.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
Jahn-Teller-like Distortion in a One-dimensional π-Conjugated Polymer
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
Ziyi Wang, Boyu Qie, Weichen Tang, Jingwei Jiang, Fujia Liu, Peter H. Jacobse, Jiaming Lu, Xinheng Li, Steven G. Louie, Felix R. Fischer, Michael F. Crommie
Structurally distorting low-dimensional {\pi}-conjugated systems can profoundly influence their electronic properties, but controlling such behavior in extended-width systems remains challenging. Here we demonstrate that a one-dimensional conjugated polymer, poly-(difluorenoheptalene-ethynylene) (PDFHE), undergoes a pronounced out-of-plane backbone distortion, equivalent to a spontaneous symmetry breaking (SSB) of its mirror symmetry. We synthesized PDFHE on noble metal surfaces and characterized its structure and electronic states using low-temperature scanning tunneling microscopy. Rather than adopting a planar, high-symmetry conformation, PDFHE relaxes into non-planar isomers stabilized by a Jahn-Teller-like mechanism that relieves an electronic instability relative to the gapped planar structure. Density functional theory calculations corroborate these findings, revealing that distortion lowers the total polymer energy and enlarges the bandgap, providing a microscopic explanation for the SSB. Our results show that even in mechanically robust extended {\pi}-systems, subtle electron-lattice coupling can spontaneously drive significant structural rearrangements.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
16 pages, 4 figures
Orbital magnetic moments in FeCr2S4 studied by x-ray magnetic circular dichroism
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
V. K. Verma, J. Patra, V. R. Singh, Y. Nonaka, G. Shibata, K. Ishigami, K. Ohgushi, Y. Tokura, T. Koide, A. Fujimori
We have investigated the element specific magnetic characteristics of single-crystal FeCr2S4 using x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD). We have found that the Fe L2,3-edge XAS spectra do not exhibit clear multiplet structures, indicating strong hybridization between the Fe 3d and S 3p orbitals, leading to delocalized rather than localized electronic states. The Fe 3d and Cr 3d spin moments are antiferromagnetically coupled, consistent with the Goodenough-Kanamori rule. The orbital magnetic moments of Fe and Cr are determined to be -0.23 and -0.017 {\mu}B/ion, respectively. The large orbital magnetic moment of Fe is due to the d6 configuration under the relatively weak tetrahedra crystal field at the Fe site, and the delocalized Fe electrons maintain the orbital degree of freedom in spite of their itinerant nature. To understand phenomena such as the gigantic Kerr rotation, it is essential to consider not only the orbital degrees of freedom but also the role of spin-orbit coupling, which induces a finite orbital magnetic moment through t2 and e level hybridization under the tetrahedral crystal field. This finite orbital moment serves as a direct indicator of spin-orbit interaction strength and links element-specific orbital magnetism to the large Kerr rotation. On the other hand, the octahedral crystal-field splitting of the Cr 3d level is large enough to result in the quenching of the orbital moment of the Cr ion in FeCr2S4.
Strongly Correlated Electrons (cond-mat.str-el)
14 pages, 6 figures
Nonperturbative quantum field theory for pseudo-Goldstone modes, slow-Goldstone modes, and their quantum chaos
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-08-21 20:00 EDT
In this work, we develop a novel form of non-perturbative theory to identify a light pseudo-Goldstone mode with a small mass, as well as a new type of Goldstone mode with a tiny slope (termed the slow-Goldstone mode), which may not be obtained via traditional perturbative methods. We demonstrate our formalism in the context of superfluids formed by Rashba spin-orbit coupled spinor bosons in a square lattice weakly interacting with a spin-anisotropic interaction. The experimental detections of these two modes, especially their roles leading to the quantum information scramblings at a finite temperature are discussed. The slow-Goldstone mode is compared with the slow light and the soft mode in the Sachdev-Ye-Kitaev models. This non-perturbative formalism can be widely applied to study other emergent particles in various quantum matter.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 5 figures, 4 appendices
Physical Review B 112, 085127 (2025)
Dynamic Vacancy Levels in CsPbCl3 Obey Equilibrium Defect Thermodynamics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Irea Mosquera-Lois, Aron Walsh
Halide vacancies are the dominant point defects in perovskites with $ V_\mathrm{Cl}$ identified as a detrimental trap for the optoelectronic performance of CsPbCl$ 3$ , with applications ranging from photodetectors to solar cells. Understanding these defects under operating conditions is key since their electronic levels exhibit large thermal fluctuations that challenge the validity of static 0 K models. However, quantitative modelling of defect processes requires hybrid density functional theory with spin-orbit coupling, which is too expensive for direct molecular dynamic simulations. To address this, we train a multi-task machine learning force field to study $ V\mathrm{Cl}$ in orthorhombic CsPbCl$ 3$ at 300 this http URL we observe strong oscillations in the optical transition level arising from the soft potential energy surface, neither the non-radiative capture barriers nor the thermodynamic charge transition levels are affected. Our results reveal that $ V\mathrm{Cl}$ is not responsible for the non-radiative losses previously assumed. Instead, its impact on performance arises from other mechanisms, such as limiting the open-circuit voltage and promoting ionic migration. Our findings demonstrate that, despite strong dynamical effects in halide perovskites, the conventional static formalism of defect theory remains valid for predicting thermodynamic behavior, providing a sound basis for the design of high-performance energy materials.
Materials Science (cond-mat.mtrl-sci)
A framework for finite-strain viscoelasticity based on rheological representations
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
Chongran Zhao, Hongyan Yuan, Ju Liu
This work presents a new constitutive and computational framework based on strain-like internal variables belonging to Sym(3) and two representative rheological configurations. The generalized Maxwell and generalized Kelvin-Voigt models are considered as prototypes for parallelly and serially connected rheological devices, respectively. For each configuration, distinct kinematic assumptions are introduced. The constitutive theory is derived based on thermomechanical principles, where the free energies capture recoverable elastic responses and dissipation potentials govern irreversible mechanisms. The evolution equations for the internal variables arise from the principle of maximum dissipation. A key insight is the structural distinction in the constitutive laws resulted from the two rheological architectures. In particular, the Kelvin-Voigt model leads to evolution equations with non-equilibrium processes coupled, which pose computational challenges for the constitutive integration. To address this, we exploit the Sherman-Morrison-Woodbury formula and extend it to tensorial equations to design an efficient strategy during constitutive integration. With that strategy, the integration can be performed based on an explicit update formula, and the algorithmic complexity scales linearly with the number of non-equilibrium processes. This framework offers both modeling flexibility and computational feasibility for simulating materials with multiple non-equilibrium processes and complex rheological architectures under finite strain.
Soft Condensed Matter (cond-mat.soft), Numerical Analysis (math.NA), Applied Physics (physics.app-ph)
Influence of local strain on the optical probing of a Ni$^{2+}$ spin in a charged self-assembled quantum dot
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
K. E. Polczynska, S. Karouaz, W. Pacuski, L. Besombes
This study explores the optical properties of quantum dots doped with a Ni$ ^{2+}$ ion that interacts with a charged exciton. Systematic magneto-optical analysis reveals that the strain distribution at the Ni$ ^{2+}$ site significantly influences its spin structure. In positively charged dots dominated by in-plane biaxial strain, the three spins states of the Ni$ ^{2+}$ (S$ _z$ =0, S$ _z$ =$ \pm$ 1) can be observed and the magneto-optical spectra enables a local strain anisotropy to be determined. However, in most of the dots, lower-symmetry strain mixes all the Ni$ ^{2+}$ spin states, thereby increasing the number of observed optical transitions. In charged dots, we identify optical transitions that share a common excited state. They form a series of $ \Lambda$ levels systems that can be individually addressed optically to determine the energy level structure. Magneto-optical measurements demonstrate that the hole-Ni$ ^{2+}$ exchange interaction is antiferromagnetic and considerably stronger than the electron-Ni$ ^{2+}$ interaction. A spin-effective model that incorporates local strain orientation can successfully reproduce key experimental results. Furthermore, we demonstrate that low-symmetry terms in the hole-Ni$ ^{2+}$ exchange interaction must be considered in order to accurately describe the emission spectra details in a magnetic field.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Electron charge dynamics and charge separation: A response theory approach
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Lionel Lacombe, Lucia Reining, Vitaly Gorelov
This study applies response theory to investigate electron charge dynamics, with a particular focus on charge separation. We analytically assess the strengths and limitations of linear and quadratic response theories in describing charge density and current, illustrated by a model that simulates charge transfer systems. While linear response accurately captures optical properties, the quadratic response contains the minimal ingredients required to describe charge dynamics and separation. Notably, it closely matches exact time propagation results in some regime that we identify. We propose and test several approximations to the quadratic response and explore the influence of higher-order terms and the effect of an on-site interaction $ U$ .
Materials Science (cond-mat.mtrl-sci), Computational Physics (physics.comp-ph)
Altermagnetic magnon transport in the \textit{d}-wave altermagnet \ch{LuFeO3}
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Edgar Galindez-Ruales, Wanting Yang, Tobias Dannegger Moumita Kundu, Jonas Köhler, Christin Schmitt Felix Fuhrmann, Akashdeep Akashdeep, Duc Minh Tran Xiaoxuan Ma, Gerhard Jakob, Shixun Cao, Ulrich Nowak, Mathias Kläui
Altermagnets exhibit a spin-split band structure despite having zero net magnetization, leading to special magnonic properties such as anisotropic magnon lifetimes and field-free spin transport. Here, we present a direct experimental demonstration of non-local magnon transport in the \textit{d}-wave altermagnet \ch{LuFeO3}, using both spin Seebeck and spin Hall effect-based injection and detection. We observe a non-local spin signal at zero magnetic field when the transport is along an altermagnetic direction, but not for transport along other directions. The observed sign reversal between two distinct altermagnetic directions in the spin Seebeck response demonstrates the altermagnetic nature of the magnon transport. In contrast, when transport is aligned along or perpendicular to the easy axis, both the first-harmonic signal and the sign-reversal effect vanish, consistent with symmetry-imposed suppression. These findings are supported by atomistic spin dynamics simulations, as well as linear spin wave theory calculations, which explain how our altermagnetic system hosts anisotropic spin Seebeck transport. Our results provide direct evidence of direction-dependent magnon splitting in altermagnets and highlight their potential for field-free magnonic spin transport, offering a promising pathway for low-power spintronic applications.
Materials Science (cond-mat.mtrl-sci)
Fabrication, characterization and mechanical loading of Si/SiGe membranes for spin qubit devices
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
Lucas Marcogliese, Ouviyan Sabapathy, Rudolf Richter, Jhih-Sian Tu, Dominique Bougeard, Lars R. Schreiber
Si/SiGe heterostructures on bulk Si substrates have been shown to host high fidelity electron spin qubits. Building a scalable quantum processor would, however, benefit from further improvement of critical material properties such as the valley splitting landscape. Flexible control of the strain field and the out-of-plane electric field $ \mathcal{E}_z$ may be decisive for valley splitting enhancement in the presence of alloy disorder. We envision the Si/SiGe membrane as a versatile scientific platform for investigating intervalley scattering mechanisms which have thus far remained elusive in conventional Si/SiGe heterostructures and have the potential to yield favourable valley splitting distributions. Here, we report the fabrication of locally-etched, suspended SiGe/Si/SiGe membranes from two different heterostructures and apply the process to realize a spin qubit shuttling device on a membrane for future valley mapping experiments. The membranes have a thickness in the micrometer range and can be metallized to form a back-gate contact for extended control over the electric field. To probe their elastic properties, the membranes are stressed by loading with a profilometer stylus at room temperature. We distinguish between linear elastic and buckling modes, each offering new mechanisms through which strain can be coupled to spin qubits.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
13 pages, 10 figures
Correlated phases in rhombohedral N-layer graphene
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Arsen Herasymchuk, Sergei G. Sharapov, Oleg V. Yazyev, Yaroslav Zhumagulov
We investigate the emergence of correlated electron phases in rhombohedral $ N$ -layer graphene due to two-valley Coulomb interactions within a low-energy $ k \cdot p$ framework. Analytical expressions for Lindhard susceptibilities in intra- and intervalley channels are derived, and the critical temperatures for phase transitions are estimated using both the random phase approximation (RPA) and the parquet approximation (PA). Within RPA, only Stoner and intervalley coherent (IVC) phases are supported, while the PA reveals a richer phase structure including particle-particle (PP) channel instabilities. We establish a general scaling law for the critical temperature with respect to layer number $ N$ , highlighting an upper bound as $ N \rightarrow \infty$ , and demonstrate a non-monotonic decrease of the critical temperature with increasing chemical potential. The PA uncovers the role of interaction symmetry: $ SU(4)$ -symmetric interactions favor intervalley Stoner order in the density channel, whereas $ SU(2) \times SU(2)$ -symmetric interactions permit a broader set of phases. A crossover in the dominant instability occurs in the particle-hole channel at a critical layer number, suggesting the emergence of magnetic or IVC phases in thicker systems. We also identify conditions under which pair-density wave (PDW) order could form in the PP channel, though its physical realization may be constrained.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
24 pages, 17 figures
Emergent superconducting stripes in two-orbital superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-21 20:00 EDT
Motivated by recent experiments in KTaO$ _3$ /EuO interface, we propose an intrinsic mechanism where superconducting stripes emerge naturally without involving disorder, charge inhomogeneity, or competing orders. Our theory is based on a two-orbital model of superconductivity, where one orbital displays a quasi-one-dimensional dispersion and the other orbital is more localized and contributes pairing interactions along the perpendicular direction. Our auxiliary-field Monte Carlo simulations demonstrate that the pairing amplitude exhibits spatial modulation such that the superconductivity naturally disaggregates into two-leg or three-leg superconducting stripes separated by non-superconducting blocks. Our work provides a promising scenario of emergent superconducting stripes in homogeneous two-dimensional systems and reveals unexpectedly rich physics in two-orbital superconductors for future materials design.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
6 pages, 4 figures
Measurement of the attractive electrosolvation force between colloidal particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
Sida Wang, Angela Le, Rowan Walker-Gibbons, Madhavi Krishnan
Direct measurement of the pair interaction potential between electrically like-charged particles in solution reveals a strong and long-ranged attractive force. This counterintuitive attraction has been suggested to arise from the orientation of solvent molecules at the interface between the object and the electrolyte. Here we report measurements of pair interaction potentials between charged microspheres with a range of surface chemistries. We demonstrate that the range of the electrosolvation attraction is substantially longer than previously held and that the range of the interaction depends on particle properties. The observations highlight significant departures from current thinking and the need for a model of interparticle interactions that accounts for the molecular nature of the solvent, its interfacial behaviour, and spatial correlations.
Soft Condensed Matter (cond-mat.soft), Biological Physics (physics.bio-ph), Chemical Physics (physics.chem-ph)
Elastic Metastability: Thermally Activated Snap-through Transitions in Nanostructures
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
Renjie Zhao, Yiquan Zhang, Chenglin Luo
The morphological snap-through transition of a bistable elastic structure typically requires external loading, unless it is miniaturized to the nanoscale, where thermal fluctuations play a significant role. We propose that metastability can emerge in microscopic elastic systems when coupled to a thermal environment, giving rise to thermally activated transitions between metastable configurations. Using atomistic simulations combined with rare event methods, we demonstrate that snap-through events can occur as well-defined thermally activated transitions in a geometrically constrained graphene nanoribbon. Well-tempered metadynamics is employed to determine the transition energetics and pathways. Notably, the temperature dependence of the transition rate constant is accurately described by generalized transition state theory in terms of the Landau free energy. This study introduces a theoretical framework for understanding elastic metastability, extends reaction rate theory to nanomechanical systems, and suggests strategies for designing temperature-responsive nanodevices.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Chemical Physics (physics.chem-ph)
Robust field re-entrant superconductivity in ferromagnetic infinite-layer rare-earth nickelates
New Submission | Superconductivity (cond-mat.supr-con) | 2025-08-21 20:00 EDT
Mingwei Yang, Jiayin Tang, Xianfeng Wu, Heng Wang, Wenjing Xu, Haoliang Huang, Zhicheng Pei, Wenjie Meng, Guangli Kuang, Jinfeng Xu, Sixia Hu, Chuanying Xi, Li Pi, Qingyou Lu, Ziqiang Wang, Qikun Xue, Zhuoyu Chen, Danfeng Li
Superconductivity and ferromagnetism are naturally competing, while their interplay can give rise to exotic quantum phases, such as triplet pairing, exemplified by heavy-fermion compounds like UTe$ _2$ , where magnetic fluctuations stabilise multiple superconducting states. However, such phenomena have remained elusive in high-temperature superconductors. Here we report the discovery of robust field-induced re-entrant superconductivity in heavily Eu-doped infinite-layer nickelate Sm$ _{0.95-x}$ Ca$ _{0.05}$ Eu$ _x$ NiO$ _2$ . In the heavily over-doped regime, we observe a remarkable superconducting state that emerges under high magnetic fields ($ >$ 6 Tesla) after the initial suppression of zero-field superconductivity. Both zero-resistance transport and Meissner diamagnetic effect confirm the superconducting nature of this high-field phase, which persists up to at least 45 Tesla. This re-entrant behaviour is featured by the coexistence of ferromagnetism and superconductivity on distinct sublattices – magnetic Eu$ ^{2+}$ ions and the Ni-O planes, respectively. Such an exotic state may arise from the compensation between external and internal exchange fields (Jaccarino-Peter effect) combined with magnetic fluctuation-enhanced pairing near quantum criticality. Our findings establish infinite-layer nickelates as a unique platform for high-temperature ferromagnetic superconductivity, opening new avenues for discovering and manipulating unconventional quantum phases in strongly correlated materials.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
Manuscript under review. 26 pages, 11 figures
Size-structured populations with growth fluctuations: Feynman–Kac formula and decoupling
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-21 20:00 EDT
Ethan Levien, Yair Heïn, Farshid Jafarpour
We study a size–structured population model of proliferating cells in which biomass accumulation and binary division occur at rates modulated by fluctuating internal phenotypes. We quantify how fluctuations in internal variables that influence both growth and division shape the distribution of population phenotypes. We derive conditions under which the distributions of size and internal state decouple. Under this decoupling, population–level expectations are obtained from lineage-level expectations by an exponential tilting given by the Feynman–Kac formula. We further characterize weaker (ensemble-specific) versions of decoupling that hold in the lineage or the population ensemble but not both. Finally, we provide a more general interpretation of the tilted expectations in terms of the mass-weighted phenotype distribution.
Statistical Mechanics (cond-mat.stat-mech), Data Analysis, Statistics and Probability (physics.data-an), Populations and Evolution (q-bio.PE)
29 pages, 4 figures
Emergent Self-propulsion of Skyrmionic Matter in Synthetic Antiferromagnets
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
Clecio C. de Souza Silva, Matheus V. Correia, Juan C. Pina Velasquez
Self-propulsion plays a crucial role in biological processes and nanorobotics, enabling small systems to move autonomously in noisy environments. Here, we theoretically demonstrate that a bound skyrmion-skyrmion pair in a synthetic antiferromagnetic bilayer can function as a self-propelled topological object, reaching speeds of up to a hundred million body lengths per second–far exceeding those of any known synthetic or biological self-propelled particles. The propulsion mechanism is triggered by the excitation of back-and-forth relative motion of the skyrmions, which generates nonreciprocal gyrotropic forces, driving the skyrmion pair in a direction perpendicular to their bond. Remarkably, thermal noise induces spontaneous reorientations of the pair and momentary reversals of the propulsion, mimicking behaviors observed in motile bacteria and microalgae.
Soft Condensed Matter (cond-mat.soft), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
Includes End Matter and Supplemental Material (total: 15 pages)
Phys. Rev. Lett. 135, 086701 (2025)
The heating and cooling of 2D electrons at low temperatures
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
A. K. Jain, J. T. Nicholls, S. N. Holmes, G. Jaliel, C. Chen, I. Farrer, D. A. Ritchie
We present measurements of the cooling length $ \ell_E$ for hot electrons in a GaAs-based high mobility two-dimensional electron gas (2DEG). The thermal measurements are performed on a long 60 $ \mu$ m-wide channel, which is Joule-heated at one end, along which there are three similar hot-electron thermocouples, spaced 30 $ \mu$ m apart. The thermocouples measure an exponentially decaying temperature profile with a characteristic length $ \ell_E$ , which decreases from 23 to 16 $ \mu$ m as the lattice temperature increases from 1.8 to 5 K. From a simple one-dimensional model of heat diffusion, we measure an inelastic scattering time which decreases from $ \tau_i \approx$ 0.36 to 0.18 ns. The measured $ \tau_i$ has a magnitude and temperature dependence consistent with acoustic phonon scattering times. We discuss how the sample design can be varied for further thermal investigations. Knowledge of the temperature profile and its gradient will prove useful in measurements of the thermal conductivity and the Nernst effect.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 4 figures
Lattice elasticity of blue phases in cholesteric liquid crystals
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
V.A.Chizhikov, A.V.Mamonova, V.E.Dmitrienko
New theoretical approaches have been developed for studying and quantitatively describing the elastic properties of cubic blue phases in cholesteric liquid crystals. Within the framework of the Landau-de Gennes theory, using the simplest blue phase with spatial group $ O^5$ ($ I432$ ) as an example, calculations of the bulk modulus and two shear moduli were performed depending on the chirality strength and temperature below the crystallization point from isotropic liquid. It is shown that the used approximations of rigid tensors and free helicoids give qualitatively similar results but differ noticeably quantitatively, therefore further experimental studies and numerical modeling of blue phase elasticity are necessary.
Soft Condensed Matter (cond-mat.soft)
8 pages, 3 figures
JETP 166 (2024) 879-888
Severe plastic deformations, mechanochemistry, and microstructure evolution under high pressure: In Situ Experiments, Four-Scale Theory, New Phenomena, and Rules
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Processes involving severe plastic deformations (SPD) and phase transformations and chemical reactions (PTs/CRs) under high pressures are widespread for obtaining new nanostructured phases and their processing, mechanochemical synthesis, military applications, and nature. SPD strongly reduce the pressure required for PTs/CRs (by one-two orders of magnitude) and PT hysteresis; lead to hidden metastable phases, which cannot be obtained otherwise, and substitute reversible PTs/CRs with irreversible ones. This review is devoted to breakthroughs in understanding multifaceted interactions between high-pressure PTs/CRs, SPD, and microstructure evolution from the viewpoint of advanced mechanics and thermodynamics of materials under stress and plastic strain tensors. A novel concept of plastic strain-induced PTs/CRs under high pressure is explored using four-scale theory and simulations (from atomistic to nano- and scale-free phase-field approaches to macroscale) coupled to in situ experiments in traditional and rotational diamond anvil cells, and their integration. Its development revealed various phenomena and misinterpretations, resolved numerous puzzles, found the first general rules in these fields, and suggested ways for economic defect-induced synthesis of high-pressure phases and nanostructures. Coupled analytical/computational/experimental approaches are developed for complete characterization of occurring processes and finding all heterogeneous scalar and tensorial fields. Applications include high-pressure torsion, surface treatment, high-pressure tribology, PTs/CRs in shear bands leading to severe transformation/reaction-induced plasticity and self-blown-up processes, mechanisms of deep-focus earthquakes, the appearance of microdiamonds in low-pressure-temperature Earth crust, and the mechanochemical origin of life beyond Earth. Unresolved problems and future directions are outlined.
Materials Science (cond-mat.mtrl-sci)
162 pages, 64 figures, and 1 table
Emergence of non-trivial phases in interacting non-Hermitian quasiperiodic chains with power-law hopping
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-08-21 20:00 EDT
Aditi Chakrabarty, Sanchayan Banerjee, Tapan Mishra, Sanjoy Datta
In the last few years, several works have identified the concurrence of the spectral, delocalization-localization and topological phase transitions in non-Hermitian quasiperiodic systems in the presence of time-reversal symmetry (TRS), with or without interaction. In this work, we investigate one-dimensional interacting non-Hermitian quasiperiodic lattices with asymmetric power-law hopping and unveil that although the Hamiltonian respects the TRS, the reality of the eigenspectrum does not necessarily indicate a topologically trivial non-Hermitian many-body localization (NHMBL) regime. In fact, we reveal the emergence of a topologically trivial intermediate regime, where the states that are primarily multifractal in nature can also possess a fully real spectrum, thereby restoring the TRS before crossing over to the NHMBL phase. Moreover, in the entire intermediate regime, the interaction completely destroys the multifractal and mobility edges observed in the non-interacting counterpart. Besides, we unveil that due to the long-range nature of the hopping, the entire topologically non-trivial ergodic regime under the periodic boundary condition does not always give rise to boundary localized skin modes under the open boundary condition. Our findings thus advances and deepens the understanding about the emergence of non-trivial phases due to the interplay of interaction and long-range hopping in non-Hermitian quasiperiodic systems.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Other Condensed Matter (cond-mat.other)
17 pages, 18 figures
A practical route to donor binding energies: The DFT-1/2 method for shallow defects
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Joshua Claes, Bart Partoens, Dirk Lamoen, Marcelo Marques, Lara K. Teles
Accurately calculating the binding energies of shallow defects requires large supercells to capture the extended nature of their wavefunctions. This makes many beyond-DFT methods, such as hybrid functionals, impractical for direct calculations, often requiring indirect or approximate approaches. However, standard DFT alone fails to provide reliable results due to the well-known band gap underestimation and delocalization errors. In this work, we employ the DFT-1/2 method to address these deficiencies while maintaining computational efficiency allowing us to reach supercells of up to 4096 atoms. We develop a practical procedure for applying DFT-1/2 to shallow defects and demonstrate its effectiveness for group V donors in silicon (P, As, Sb, Bi). By using an extrapolation scheme to infinite supercell size, we obtain accurate binding energies with minimal computational overhead. This approach offers a simple and direct method for calculating donor binding energies.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Computational Physics (physics.comp-ph), Quantum Physics (quant-ph)
Intrinsic Linear Response from Zeeman Quantum Geometry in 2D Unconventional Magnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
Neelanjan Chakraborti, Sudeep Kumar Ghosh, Snehasish Nandy
Unconventional magnets with zero net magnetization yet momentum-dependent spin splitting constitute a newly identified class of materials that provide a rich platform for quantum-geometry-driven transport phenomena. Exploiting the interplay between momentum translation and spin rotation, we uncover a distinct linear transport response governed by a generalized quantum geometric tensor, the Zeeman quantum geometric tensor (ZQGT). We show that the ZQGT drives a linear intrinsic gyrotropic magnetic current (IGMC) in the three prototypical two-dimensional unconventional magnets: a time-reversal-broken $ d_{x^2 - y^2}$ altermagnet, a time-reversal-symmetric $ p$ -wave magnet, and a mixed $ d$ -wave altermagnet. Depending on symmetry, these magnets exhibit longitudinal, transverse, or combined conduction and displacement IGMCs in the presence of spin-orbit coupling. Notably, this response persists even when conventional Berry curvature contributions vanish, offering a unique probe of hidden spin-split band structures of unconventional magnets. In particular, for mixed $ d$ -wave altermagnets, symmetric Berry curvature and antisymmetric quantum metric respectively generate longitudinal conduction IGMC and transverse displacement IGMC- responses absent in conventional quantum geometry. The predicted signatures, relevant to compounds such as RuO$ _2$ , CrSb, and MnTe, provide experimentally accessible diagnostics for distinguishing unconventional magnetic phases. These findings position the ZQGT as a powerful framework for probing and controlling transport in next-generation quantum materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
9 pages, 3 figures, comments are welcome
Near-resonant nuclear spin detection with megahertz mechanical resonators
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
Diego A. Visani, Letizia Catalini, Christian L. Degen, Alexander Eichler, Javier del Pino
Mechanical resonators operating in the megahertz range have become a versatile platform for fundamental and applied quantum research. Their exceptional properties, such as low mass and high quality factor, make them also appealing for force sensing experiments. In this work, we propose a method for detecting, and ultimately controlling, nuclear spins by coupling them to megahertz resonators via a magnetic field gradient. Dynamical backaction between the sensor and an ensemble of $ N$ nuclear spins produces a shift in the sensor’s resonance frequency. The mean frequency shift due to the Boltzmann polarization is challenging to measure in nanoscale sample volumes. Here, we show that the fluctuating polarization of the spin ensemble results in a measurable increase of the resonator’s frequency variance. On the basis of analytical as well as numerical results, we predict that the variance measurement will allow single nuclear spin detection with existing resonator devices.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
arXiv admin note: substantial text overlap with arXiv:2311.16273
Trion polaron problem in bulk and two-dimensional materials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
V. Shahnazaryan, A. Kudlis, K. Varga, I. A. Shelykh, I. V. Tokatly
We develop a microscopic theoryof the trion polaron: a bound state of two electrons and one hole, dressed by longitudinal optical (LO) phonons. Starting from the Frohlich Hamiltonian, which describes the interaction of charged particles with LO phonons in three-dimensional (bulk) and two-dimensional (monolayer) polar crystals, we adopt the intermediate coupling variational approximation of Lee, Low, and Pines, and generalize it for the three-body problem. This yields an effective three-particle Hamiltonian with renormalized electron-electron and electron-hole interactions, similar to those obtained for exciton polaron and bipolaron problems. We compute the binding energies for a family of bulk perovskite materials and several atomic monolayer materials characterized by pronounced polar effects, providing quantitative benchmarks for spectroscopic measurements.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Controlling Skyrmion Lattice Orientation with Local Magnetic Field Gradients
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
Duc Minh Tran, Edoardo Mangini, Elizabeth M. Jefremovas, Fabian Kammerbauer, Dennis Meier, Robert Frömter, Mathias Kläui
Precise control over the formation and arrangement of magnetic skyrmion lattices is essential for understanding their emergent behavior and advancing their integration into spintronic and magnonic devices. We report on a simple and minimally invasive technique to nucleate and manipulate skyrmion lattices in soft magnetic CoFeB using single-pass magnetic force microscopy (MFM). By tuning the scan-line spacing to match the intrinsic stripe domain periodicity, the stray field gradient from the MFM tip induces reversible transitions from stripe domains to isolated skyrmions and locally ordered lattices. The resulting skyrmion positions are extracted to compute the local orientational order parameter $ \psi_6$ , enabling quantitative evaluation of lattice ordering. A systematic improvement in $ \langle |\psi_6| \rangle$ is observed with repeated scanning, indicating a transition from a disordered state to ordered hexagonal lattices. Furthermore, we demonstrate that the lattice orientation can be deterministically rotated by changing the scanning direction, as confirmed by both real-space analysis and fast Fourier transformations. This method enables the controlled creation, reordering, and deletion of metastable skyrmion textures on demand. Our approach establishes a practical and accessible platform for studying two-dimensional phase behavior in topological spin systems, offering direct and reconfigurable control over lattice symmetry, order, and orientation.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Gauge flux generations of weakly magnetized Dirac spin liquid in a kagomé lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Si-Yu Pan, Jiahao Yang, Gang V. Chen
Inspired by the recent progress on the Dirac spin liquid and the kagomé lattice antiferromagnets, we revisit the U(1) Dirac spin liquid on the kagomé lattice and consider the response of this quantum state to the weak magnetic field by examining the matter-gauge coupling. Even though the system is in the strong Mott insulating regime, the Zeeman coupling could induce the internal U(1) gauge flux with the assistance of the Dzyaloshinskii-Moriya interaction. In addition to the perturbatively-induced non-uniform flux from the microscopic interactions, the system spontaneously generates the uniform U(1) gauge flux in a non-perturbative fashion to create the spinon Landau levels and thus gains the kinetic energy for the spinon matters. Renormalized mean-field theory is employed to validate these two flux generation mechanisms. The resulting state is argued to be an ordered antiferromagnet with the in-plane magnetic order, and the gapless Goldstone mode behaves like the gapless gauge boson and the spinons appear at higher energies. The dynamic properties of this antiferromagnet, and the implication for other matter-gauge-coupled systems are discussed.
Strongly Correlated Electrons (cond-mat.str-el)
14pages, 13figures
Sideband Spectroscopy in the Strong Driving Regime: Volcano Transparency and Sideband Anomaly
New Submission | Other Condensed Matter (cond-mat.other) | 2025-08-21 20:00 EDT
Luka Antonic, Sergey Hazanov, Sergei Masis, Daniel Podolsky, Eyal Buks
We study the response of a spin to two crossed magnetic fields: a strong and fast transverse field, and a weak and slow longitudinal field. We characterize the sideband response at the sum and the difference of driving frequencies over a broad range of parameters. In the strong transverse driving regime, the emission spectrum has a characteristic volcano lineshape with a narrow central transparency region surrounded by asymmetric peaks. Next, we couple the spin to a nonlinear cavity that both drives and measures it. In a sufficiently slow longitudinal field, the emission spectrum exhibits anomalous behavior, where the resonances in both the right and left sidebands lie on the same side of the central resonance. The theoretical results are compared to the experimental measurement of the emission of substitutional nitrogen P1 and nitrogen-vacancy NV$ ^-$ defects in diamond.
Other Condensed Matter (cond-mat.other), Optics (physics.optics), Quantum Physics (quant-ph)
21 pages, 15 figures
Equipartition and the temperature of maximum density of TIP4/2005 water
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
Dilipkumar N. Asthagiri, Thomas L. Beck
We simulate TIP4P/2005 water in the temperature range of 257 K to 318 K with time steps of $ \delta =$ 0.25, 0.50, and 2.0 fs. Within the computed statistical uncertainties, the density-temperature behavior obtained using 0.25 fs and 0.50 fs are in excellent agreement with each other but differ from those obtained using $ \delta t = 2.0$ fs, a choice that leads to a breakdown of equipartition. The temperature of maximum density (TMD) is 277.15 K with $ \delta t = $ 0.25 fs or 0.50 fs, but is shifted to 273.15 K for simulations with $ \delta t = 2.0$ fs. This shift is comparable in magnitude to the shift in TMD due to nuclear quantum effects, emphasizing the care required in the parameterization and classical statistical mechanical simulation of a fluid that displays nontrivial nuclear quantum effects under ambient conditions. Enhancing the water-water dispersion interaction, as has been recommended for modeling disordered solvated proteins, degrades the description of the liquid-vapor phase envelope.
Soft Condensed Matter (cond-mat.soft), Chemical Physics (physics.chem-ph)
Delayed transitions, promoted states and multistability in a pressure-driven nematic under an electric field
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-08-21 20:00 EDT
We consider the effects of an applied pressure gradient on the classical Freedericksz transition, finding a delayed transition, the promotion of particular director configurations and even pressure-induced multistability. Using the theoretical framework developed by Ericksen and Leslie, we find that the applied pressure gradient adapts the normal pitchfork bifurcation at critical applied voltage, leading to both a delayed bifurcation to higher voltages and a transformation from a supercritical to a subcritical bifurcation so that within a range of voltages there are at least two possible steady states. This range of voltages grows with increasing pressure gradient and eventually includes the zero voltage state so that, for sufficiently strong flow, there are at least two steady states at zero applied voltage. For sufficiently high pressure gradients, we also find that flow-alignment can create a completely new attracting steady state, one that is unstable without flow. We provide a flow-strength-electric field parameter plane that summarises the parameter ranges for which there are multiple steady states and suggest realistic mechanisms to move between these states, as well as an analytical model for the delayed Freedericksz transition effect. The novel steady states found in this work give the possibility of director and flow hysteresis in microfluidic devices.
Soft Condensed Matter (cond-mat.soft)
Core position-dependent gyrotropic and damping contributions to the Thiele equation approach for accurate spin-torque vortex oscillator dynamics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-08-21 20:00 EDT
Colin Ducarme, Simon De Wergifosse, Flavio Abreu Araujo
Understanding the nonlinear dynamics of magnetic vortices in spin-torque vortex oscillators (STVOs) is essential for their application in neuromorphic computing. Existing models either rely on the standard Thiele equation approach (TEA), which offer only qualitative predictions, or on micromagnetic simulations (MMS), which are computationally demanding. We present a refined Thiele approach that incorporates the deformation of the vortex profile for the evaluation of the gyrotropic and damping terms. In this manuscript, a more realistic ansatz of the vortex magnetization profile is introduced to extract these effective parameters semi-analytically. A method to extract the gyrotropic and damping terms directly from MMS is also presented. The resulting expressions are benchmarked against state-of-the-art analytical derivations, and reveal a damping anisotropy of the vortex core. This framework captures the essential nonlinearities of STVO dynamics with high fidelity at low computational cost, paving the way for predictive modeling of large-scale neuromorphic circuits based on STVOs.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 3 figures
Electron coherent phonon coupling in Pr${0.5}$Ca${1.5}$MnO$_4$ measured with ultrafast broadband spectroscopy
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Emmanuel B. Amuah, Khalid M. Siddiqui, Maurizio Monti, Daniel Pérez-Salinas, Hanna Strojecka, Thomas H. Meyland, Allan S. Johnson, Simon E. Wall
Photoexcitation of single-layered La$ _{0.5}$ Mn$ _{1.5}$ MnO$ _4$ has played a key role in understanding orbital ordering and non-thermal states in the manganites. However, while orbital ordering in La$ _{0.5}$ Sr$ _{1.5}$ MnO$ _4$ breaks the in-plane C$ _4$ symmetry, many layered manganites show much more complex phase diagrams in which orbital ordering emerges from an already symmetry-broken high-temperature phase and also exhibit additional low-temperature phases. In this work, we examine the role of these phases in relation to orbital ordering in the single-layered manganite Pr$ _{0.5}$ Ca$ _{1.5}$ MnO$ _4$ with a combination of optical reflection anisotropy and ultrafast broadband pump-probe spectroscopy. We find that the reflection anisotropy, measured in equilibrium, is strongly sensitive to charge and orbital-ordering transition only. However, the ultrafast response, measuring the non-equilibrium state is sensitive to all phases. In particular, we deduce that coherent phonons modulate unoccupied electronic states that are sensitive to the different phases of the material. This gives rise to a non-linear scaling of the phonon signal with pump fluence at specific probe wavelengths.
Strongly Correlated Electrons (cond-mat.str-el)
10 Pages, 7 Figures
Suppression of the valence transition in solution-grown single crystals of Eu$_2$Pt$6$Al${15}$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Juan Schmidt, Dominic H. Ryan, Oliver Janka, Jutta Kösters, Carsyn L. Mueller, Aashish Sapkota, Rafaela F. S. Penacchio, Tyler J. Slade, Sergey L. Bud’ko, Paul C. Canfield
The study of Eu intermetallic compounds has allowed the exploration of valence fluctuations and transitions in 4f electron systems. Recently, a Eu$ _2$ Pt$ _6$ Al$ _{15}$ phase synthesized by arc-melting followed by a thermal treatment was reported [M. Radzieowski \textit{et al.}, J Am Chem Soc 140(28), 8950-8957 (2018)], which undergoes a transition upon cooling below 45K that was interpreted as a valence transition from Eu$ ^{2+}$ to Eu$ ^{3+}$ . In this paper, we present the discovery of another polymorph of Eu$ _2$ Pt$ _6$ Al$ _{15}$ obtained by high-temperature solution growth, that presents different physical properties than the arc-melted polycrystalline sample. Despite the similarities in crystal structure and chemical composition, the Eu valence transition is almost fully suppressed in the solution-grown crystals, allowing the moments associated with the Eu$ ^{2+}$ state to order antiferromagnetically at around 14K. A detailed analysis of the crystal structure using single crystal X-ray diffraction reveals that, although the solution grown crystals are built from the same constituent layers as the arc-melted samples, these layers present a different stacking. The effect of different thermal treatments is also studied. Different anneal procedures did not result in significant changes of the intrinsic properties, and only by arc-melting and quenching the crystals we were able to convert them into the previously reported polymorph.
Materials Science (cond-mat.mtrl-sci)
15 pages, 14 figures
Physics-Informed ML Exploration of Structure-Transport Relationships in Hard Carbon
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Nikhil Rampal, Stephen E. Weitzner, Fredrick Omenya, Marissa Wood, David M. Reed, Xiaolin Li, Jonathan R. I. Lee, Liwen F. Wan
Sodium-ion batteries are a cost-effective and sustainable alternative to lithium-ion systems for large-scale energy storage. Hard carbon (HC) anodes, composed of disordered graphitic and amorphous domains, offer high capacity but exhibit complex, poorly understood ion transport behavior. In particular, the relationship between local microstructure and sodium mobility remains unresolved, hindering rational performance optimization. Here, we introduce a data-driven framework that combines machine-learned interatomic potentials with molecular dynamics simulations to systematically investigate sodium diffusion across a broad range of carbon densities and sodium loadings. By computing per-ion structural descriptors, we identify the microscopic factors that govern ion transport. Unsupervised learning uncovers distinct diffusion modes, including hopping, clustering, and void trapping, while supervised analysis highlights tortuosity and NaNa coordination as primary determinants of mobility. Correlation mapping further connects these transport regimes to processing variables such as bulk density and sodium content. This physics-informed approach establishes quantitative structure-transport relationships that capture the heterogeneity of disordered carbon. Our findings deliver mechanistic insights into sodium-ion dynamics and provide actionable design principles for engineering high-performance HC anodes in next-generation battery systems.
Materials Science (cond-mat.mtrl-sci)
Carrier mobilities and electron-phonon interactions beyond DFT
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-08-21 20:00 EDT
Aleksandr Poliukhin, Nicola Colonna, Francesco Libbi, Samuel Poncé, Nicola Marzari
Electron-phonon coupling is a key interaction that governs diverse physical processes such as carrier transport, superconductivity, and optical absorption. Calculating such interactions from first-principles with methods beyond density-functional theory remains a challenge. We introduce here a finite-difference framework for computing electron-phonon couplings for any electronic structure method that provides eigenvalues and eigenvectors, and showcase applications for hybrid and Koopmans functionals, and $ GW$ many-body perturbation theory. Our approach introduces a novel projectability scheme based on eigenvalue differences and bypasses many of the limitations of the direct finite difference methods. It also leverages symmetries to reduce the number of independent atomic displacements, thereby keeping computational costs manageable. This approach enables seamless integration with established first-principles codes for generating displaced supercells, performing Wannier interpolations, and evaluating transport properties. Applications to silicon and gallium arsenide show that advanced electronic-structure functionals predict different electron-phonon couplings and modify band curvatures, resulting in much more accurate estimates of intrinsic carrier drift mobilities and effective masses. In general, our method provides a robust and accessible framework for exploring electron-phonon interactions in complex materials with state-of-the-art electronic structure methods.
Materials Science (cond-mat.mtrl-sci)
11 pages, 4 figures
Universal winding properties of chiral active motion
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-08-21 20:00 EDT
Ion Santra, Urna Basu, Sanjib Sabhapandit
We propose the area swept $ A(t)$ and the winding angle $ \Omega(t)$ as the key observables to characterize chiral active motion. We find that the distributions of the scaled area and the scaled winding angle are described by universal scaling functions across all well-known models of active particles, parametrized by the chirality $ \omega$ , along with a self-propulsion speed $ v_0$ , and the persistence time $ \tau$ . In particular, we show that, at late times, the average winding angle grows logarithmically with time $ \la\Omega \ra\sim(\omega\tau/2),\ln t$ , while the average area swept has a linear temporal growth $ \la A(t)\ra\simeq(\omega\tau D_{\text{eff}}),t$ , where $ D_{\text{eff}}=v_0^2 \tau /[2(1+ \omega^2 \tau^2)]$ is the effective diffusion coefficient. Moreover, we find that the distribution of the scaled area $ z=[A-\la A\ra]/(2D_{\text{eff}}t)$ is described by the universal scaling function $ F_{\text{ch}}(z)=\text{sech}(\pi z)$ . From extensive numerical evidence, we conjecture the emergence of a new universal scaling function $ G_{\text{ch}}(z)=\mathcal {N}/[e^{\alpha z} + e^{-\beta z}]$ for the distribution of the scaled winding angle $ z=\Omega/[\ln t]$ , where the parameters $ \alpha$ and $ \beta$ are model-dependent and $ \mathcal{N}$ is the normalization constant. In the absence of chirality, i.e., $ \omega=0$ , the scaling function becomes $ G_{\text{ch}}(z)=(\alpha/\pi),\mathrm{sech}(\alpha z)$ .
Statistical Mechanics (cond-mat.stat-mech), Soft Condensed Matter (cond-mat.soft)
Anyon superfluidity of excitons in quantum Hall bilayers
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-08-21 20:00 EDT
Zhaoyu Han, Taige Wang, Zhihuan Dong, Michael P. Zaletel, Ashvin Vishwanath
The charged anyons of a fractional quantum Hall fluid are necessarily dispersionless due to the continuous magnetic translation symmetry. Neutral anyons, however, can disperse, resulting in a much richer space of possible ``daughter’’ states when doped to finite density. We discuss a natural realization of such physics in quantum Hall bilayers, where a finite density of excitons with fractional statistics is argued to give rise to `anyonic exciton superfluidity,’ the charge-neutral analog of anyon superconductivity. In a balanced bilayer of two Laughlin $ \nu = 1/3$ states, the minimal interlayer exciton carries anyonic exchange statistics. A finite density of these excitons is argued to yield an exciton superfluid stitched to a specific bulk topological order and edge spectrum. Such superfluidity should be most robust near the direct transition into the Halperin $ (112)$ state, and near analogous transitions in the bilayer Jain sequence at total filling $ \nu_\text{T} = 2\times \frac{n}{2n+1}$ . These topological transitions can be described by Chern-Simons QED$ 3$ , from which we derive several novel and general properties of anyon superfluidity near such transitions, including an anomalously large superfluid stiffness of $ \kappa\text{s} \propto |\delta\nu|^{1/2}$ at layer imbalance fraction $ \delta\nu$ . A notable feature of the phase diagrams we construct is the prevalence of spatial symmetry breaking, driven by an underlying composite Fermi surface. Our results can be directly tested with currently available experimental techniques. We compare our theory with existing data and make concrete predictions for future measurements, including higher-pseudospin exciton superfluids when doping higher Jain fractions.
Strongly Correlated Electrons (cond-mat.str-el)