CMP Journal 2025-04-18
Statistics
Nature Physics: 1
Science: 6
Physical Review Letters: 10
Physical Review X: 1
Review of Modern Physics: 1
arXiv: 58
Nature Physics
Interplay of actin nematodynamics and anisotropic tension controls endothelial mechanics
Original Paper | Biological physics | 2025-04-17 20:00 EDT
Claire A. Dessalles, Nicolas Cuny, Arthur Boutillon, Paul F. Salipante, Avin Babataheri, Abdul I. Barakat, Guillaume Salbreux
Blood vessels expand and contract actively as they continuously experience dynamic external stresses from blood flow. The mechanical response of the vessel wall is that of a composite material: its mechanical properties depend on its cellular components, which change dynamically as the cells respond to external stress. Mapping the relationship between these underlying cellular processes and emergent tissue mechanics is an ongoing challenge, particularly in endothelial cells. Here we assess the mechanics and cellular dynamics of an endothelial tube using a microstretcher that mimics the native environment of blood vessels. The characterization of the instantaneous monolayer elasticity reveals a strain-stiffening, actin-dependent and substrate-responsive behaviour. After a physiological pressure increase, the tissue displays a fluid-like expansion, with the reorientation of cell shape and actin fibres. We introduce a mechanical model that considers the actin fibres as a network in the nematic phase and couples their dynamics with active and elastic fibre tension. The model accurately describes the response to the pressure of endothelial tubes.
Biological physics, Soft materials
Science
Casz1 is required for both inner hair cell fate stabilization and outer hair cell survival
Research Article | Development | 2025-04-18 03:00 EDT
Yuwei Sun, Minhui Ren, Yu Zhang, Shuting Li, Zhengnan Luo, Suhong Sun, Shunji He, Guangqin Wang, Di Zhang, Suzanne L. Mansour, Lei Song, Zhiyong Liu
Cochlear inner hair cells (IHCs) and outer hair cells (OHCs) require different transcription factors for their cell fate stabilization and survival, which suggests that separate mechanisms are involved. In this study, we found that the transcription factor Casz1 is crucial for early IHC fate consolidation and for OHC survival during mouse development. Loss of Casz1 resulted in transdifferentiation of IHCs into OHCs, without affecting OHC production. However, long-term OHC survival was compromised in Casz1 mutant mice. In addition, the transcription factor Gata3 was down-regulated in Casz1-deleted IHCs, and overexpressing Gata3 partially rescued IHC properties, OHC numbers, and hearing in Casz1-deleted mice. Thus, Casz1 plays critical roles in early IHC fate stabilization and OHC survival and could potentially provide a lead for therapies aimed at regenerating both IHCs and OHCs.
Adaptation repeatedly uses complex structural genomic variation
Research Article | Evolution | 2025-04-18 03:00 EDT
Zachariah Gompert, Jeffrey L. Feder, Thomas L. Parchman, Nicholas P. Planidin, Frederick J. H. Whiting, Patrik Nosil
Structural elements are widespread across genomes, but their complexity and role in repeatedly driving local adaptation remain unclear. In this work, we use phased genome assemblies to show that adaptive divergence in cryptic color pattern in a stick insect is repeatedly underlain by structural variation, but not a simple chromosomal inversion. We found that color pattern in populations of stick insects on two mountains is associated with translocations that have also been inverted. These translocations differ in size and origin on each mountain, but they overlap partially and involve some of the same gene regions. Moreover, this structural variation is subject to divergent selection and arose without introgression between species. Our results show how the origin of structural variation provides a mechanism for repeated bouts of adaptation.
Deep-tissue transcriptomics and subcellular imaging at high spatial resolution
Research Article | Tissue imaging | 2025-04-18 03:00 EDT
Valentina Gandin, Jun Kim, Liang-Zhong Yang, Yumin Lian, Takashi Kawase, Amy Hu, Konrad Rokicki, Greg Fleishman, Paul Tillberg, Alejandro Aguilera Castrejon, Carsen Stringer, Stephan Preibisch, Zhe J. Liu
Limited color channels in fluorescence microscopy have long constrained spatial analysis in biological specimens. We introduce cycle hybridization chain reaction (cycleHCR), a method that integrates multicycle DNA barcoding with HCR to overcome this limitation. cycleHCR enables highly multiplexed imaging of RNA and proteins using a unified barcode system. Whole-embryo transcriptomics imaging achieved precise three-dimensional gene expression and cell fate mapping across a specimen depth of ~310 μm. When combined with expansion microscopy, cycleHCR revealed an intricate network of 10 subcellular structures in mouse embryonic fibroblasts. In mouse hippocampal slices, multiplex RNA and protein imaging uncovered complex gene expression gradients and cell-type-specific nuclear structural variations. cycleHCR provides a quantitative framework for elucidating spatial regulation in deep tissue contexts for research and has potential diagnostic applications.
Structural basis for nucleolin recognition of MYC promoter G-quadruplex
Research Article | Structural biology | 2025-04-18 03:00 EDT
Luying Chen, Jonathan Dickerhoff, Ke-wei Zheng, Satchal Erramilli, Hanqiao Feng, Guanhui Wu, Buket Onel, Yuwei Chen, Kai-Bo Wang, Megan Carver, Clement Lin, Saburo Sakai, Jun Wan, Charles Vinson, Laurence Hurley, Anthony A. Kossiakoff, Nanjie Deng, Yawen Bai, Nicholas Noinaj, Danzhou Yang
The MYC oncogene promoter G-quadruplex (MycG4) regulates transcription and is a prevalent G4 locus in immortal cells. Nucleolin, a major MycG4-binding protein, exhibits greater affinity for MycG4 than for nucleolin recognition element (NRE) RNA. Nucleolin’s four RNA binding domains (RBDs) are essential for high-affinity MycG4 binding. We present the 2.6-angstrom crystal structure of the nucleolin-MycG4 complex, revealing a folded parallel three-tetrad G-quadruplex with two coordinating potassium ions (K+), interacting with RBD1, RBD2, and Linker12 through its 6-nucleotide (nt) central loop and 5’ flanking region. RBD3 and RBD4 bind MycG4’s 1-nt loops as demonstrated by nuclear magnetic resonance (NMR). Cleavage under targets and tagmentation sequencing confirmed nucleolin’s binding to MycG4 in cells. Our results revealed a G4 conformation-based recognition by a regulating protein through multivalent interactions, suggesting that G4s are nucleolin’s primary cellular substrates, indicating G4 epigenetic transcriptional regulation and helping G4-targeted drug discovery.
The genetic architecture of cell type-specific cis regulation in maize
Research Article | Plant genetics | 2025-04-18 03:00 EDT
Alexandre P. Marand, Luguang Jiang, Fabio Gomez-Cano, Mark A. A. Minow, Xuan Zhang, John P. Mendieta, Ziliang Luo, Sohyun Bang, Haidong Yan, Cullan Meyer, Luca Schlegel, Frank Johannes, Robert J. Schmitz
Gene expression and complex phenotypes are determined by the activity of cis-regulatory elements. However, an understanding of how extant genetic variants affect cis regulation remains limited. Here, we investigated the consequences of cis-regulatory diversity using single-cell genomics of more than 0.7 million nuclei across 172 Zea mays (maize) inbreds. Our analyses pinpointed cis-regulatory elements distinct to domesticated maize and revealed how historical transposon activity has shaped the cis-regulatory landscape. Leveraging population genetics principles, we fine-mapped about 22,000 chromatin accessibility-associated genetic variants with widespread cell type-specific effects. Variants in TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR-binding sites were the most prevalent determinants of chromatin accessibility. Finally, integrating chromatin accessibility-associated variants, organismal trait variation, and population differentiation revealed how local adaptation has rewired regulatory networks in unique cellular contexts to alter maize flowering.
Computational design of serine hydrolases
Research Article | Enzyme design | 2025-04-18 03:00 EDT
Anna Lauko, Samuel J. Pellock, Kiera H. Sumida, Ivan Anishchenko, David Juergens, Woody Ahern, Jihun Jeung, Alexander F. Shida, Andrew Hunt, Indrek Kalvet, Christoffer Norn, Ian R. Humphreys, Cooper Jamieson, Rohith Krishna, Yakov Kipnis, Alex Kang, Evans Brackenbrough, Asim K. Bera, Banumathi Sankaran, K. N. Houk, David Baker
The design of enzymes with complex active sites that mediate multistep reactions remains an outstanding challenge. With serine hydrolases as a model system, we combined the generative capabilities of RFdiffusion with an ensemble generation method for assessing active site preorganization at each step in the reaction to design enzymes starting from minimal active site descriptions. Experimental characterization revealed catalytic efficiencies (kcat/Km) up to 2.2 × 105 M-1 s-1 and crystal structures that closely match the design models (Cα root mean square deviations <1 angstrom). Selection for structural compatibility across the reaction coordinate enabled identification of new catalysts remove with five different folds distinct from those of natural serine hydrolases. Our de novo approach provides insight into the geometric basis of catalysis and a roadmap for designing enzymes that catalyze multistep transformations.
Physical Review Letters
Experimental Single-Copy Distillation of Quantumness from Higher-Dimensional Entanglement
Research article | Quantum correlations in quantum information | 2025-04-17 06:00 EDT
Xiao-Xu Fang, Gelo Noel M. Tabia, Kai-Siang Chen, Yeong-Cherng Liang, and He Lu
Entanglement is at the heart of quantum theory and is responsible for various quantum-enabling technologies. In practice, during its preparation, storage, and distribution to the intended recipients, this valuable quantum resource may suffer from noisy interactions that reduce its usefulness for the desired information-processing tasks. Conventional schemes of entanglement distillation aim to alleviate this problem by performing collective operations on multiple copies of these decohered states and sacrificing some of them to recover Bell pairs. However, for this scheme to work, the states to be distilled should already contain a large enough fraction of maximally entangled states before these collective operations. Not all entangled quantum states meet this premise. Here, by using the paradigmatic family of two-qutrit Werner states as an exemplifying example, we experimentally demonstrate how one may use single-copy local filtering operations to meet this requirement and to recover the quantumness hidden in these higher-dimensional states. Among others, our results provide the first proof-of-principle experimental certification of the Bell-nonlocal properties of these intriguing entangled states, the activation of their usefulness for quantum teleportation, dense coding, and an enhancement of their quantum steerability, and hence usefulness for certain discrimination tasks. Our theoretically established lower bounds on the steering robustness of these states, when they admit a symmetric quasiextension or a bosonic symmetric extension, and when they show hidden dense-codability, may also be of independent interest.
Phys. Rev. Lett. 134, 150201 (2025)
Quantum correlations in quantum information, Quantum correlations, foundations & formalism, Quantum foundations
Global Symmetries, Code Ensembles, and Sums over Geometries
Research article | Chern-Simons gauge theory | 2025-04-17 06:00 EDT
Ahmed Barbar, Anatoly Dymarsky, and Alfred D. Shapere
We consider Abelian topological quantum field theories (TQFTs) in 3D and show that gaugings of invertible global symmetries naturally give rise to additive codes. These codes emerge as nonanomalous subgroups of the 1-form symmetry group, parametrizing the fusion rules of condensable TQFT anyons. The boundary theories dual to TQFTs with a maximal symmetry subgroup gauged, i.e., with the corresponding anyons condensed, are ‘’code’’ conformal field theories (CFTs). This observation bridges together, in the holographic sense, results on 1-form symmetries of 3D TQFTs with developments connecting codes to 2D CFTs. Building on this relationship, we proceed to consider the ensemble of maximal gaugings (topological boundary conditions) in a general, not necessarily Abelian 3D TQFT, and propose that the resulting ensemble of boundary CFTs has a holographic description as a gravitational theory: the bulk TQFT summed over topologies.
Phys. Rev. Lett. 134, 151603 (2025)
Chern-Simons gauge theory, Conformal field theory, Gauge-gravity dualities, Topological field theories
Axion Detection Experiments Can Probe Majoron Models
Research article | Particle dark matter | 2025-04-17 06:00 EDT
Qiuyue Liang, Xavier Ponce Díaz, and Tsutomu T. Yanagida
The majoron is a well-motivated light (pseudo-Nambu-Goldstone) boson associated with the spontaneous breaking of a global lepton-number symmetry. In this Letter, we relate the spontaneous breaking scale to its soft-breaking mass by requiring that the majoron is the main component of the dark matter. An electromagnetic-anomalous coupling can be induced by minimally modifying the original majoron model, surprisingly, predicting a parameter region that largely overlaps with the QCD-axion dark matter band. Thus, we expect that axion search experiments to be able to probe majoron models.
Phys. Rev. Lett. 134, 151803 (2025)
Particle dark matter, Axion-like particles, Hypothetical scalars, Majorana neutrinos, Baryon & lepton number symmetries
Universality in the Near-Side Energy-Energy Correlator
Research article | Quantum chromodynamics | 2025-04-17 06:00 EDT
Xiaohui Liu, Werner Vogelsang, Feng Yuan, and Hua Xing Zhu
We investigate the energy-energy correlator (EEC) of hadrons produced on the same side in ${e}^{+}{e}^{- }$ annihilation or in leading jets in $pp$ collisions. We observe a remarkable universality of the correlator. Using a nonperturbative transverse momentum dependent (TMD) fragmentation function to model the transition from the ‘’free-hadron’’ region to the perturbative collinear region, we are able to describe the near-side shapes and peaks over a wide range of energy for both the ${e}^{+}{e}^{- }$ annihilation and the $pp$ jet substructure measurements in terms of just two parameters. We present further predictions for the ratio of the projected three-point energy correlator to the EEC. The excellent agreement between our calculations and the experimental data may provide new insights into the role of nonperturbative physics for EECs, and suggests the possibility of exploring nonperturbative TMDs using theoretical tools developed for the energy correlators.
Phys. Rev. Lett. 134, 151901 (2025)
Quantum chromodynamics, Quark & gluon jets, Strong interaction, Transverse momentum dependent distribution
Generation of Neutron Airy Beams
Research article | Cold atoms & matter waves | 2025-04-17 06:00 EDT
Dusan Sarenac, Owen Lailey, Melissa E. Henderson, Huseyin Ekinci, Charles W. Clark, David G. Cory, Lisa DeBeer-Schmitt, Michael G. Huber, Jonathan S. White, Kirill Zhernenkov, and Dmitry A. Pushin
The Airy wave packet is a solution to the potential-free Schr"odinger equation that exhibits remarkable properties such as self-acceleration, nondiffraction, and self-healing. Although Airy beams are now routinely realized with electromagnetic waves and electrons, the implementation with neutrons has remained elusive due to small transverse coherence lengths, low fluence rates, and the absence of neutron lenses. In this Letter, we overcome these challenges through a holographic approach and present the first experimental demonstration of neutron Airy beams. The presented techniques pave the way for fundamental physics studies with Airy beams of nonelementary particles, the development of novel neutron optics components, and the realization of neutron Airy-vortex beams.
Phys. Rev. Lett. 134, 153401 (2025)
Cold atoms & matter waves, Neutron physics, Scattering theory, Neutrons, Holography, Imaging & optical processing, Neutron diffraction, Neutron scattering, Small angle neutron scattering
Fate of Thermalization of Ultracold Fermions with Two-Body Dissipation
Research article | Cold and ultracold molecules | 2025-04-17 06:00 EDT
Xin-Yuan Gao and Yangqian Yan
Two-body inelastic collisions arising from chemical reactions are prevalent in ultracold fermionic and bosonic molecular gases. Although recent advancements have achieved quantum degeneracy in these systems, loss dynamics are typically modeled phenomenologically using rate equations that often assume thermalization during chemical reactions. In this study, we employ the inelastic quantum Boltzmann equation to analyze particle loss, temperature evolution, and momentum distributions in single-component Fermi gases from first principles. Our results demonstrate that the conventional particle-number rate equation accurately describes the dynamics in trapped systems but fails to capture the behavior in homogeneous systems. Notably, under pure $p$-wave inelastic collisions and zero elastic collisions, we find that systems prepared near or above quantum degeneracy remain in a thermal state, whereas systems initialized deep within degeneracy exhibit nonequilibrium dynamics. Our theoretical predictions align well with recent experimental observations in trapped systems, and our claim can be further verified in atomic systems with induced two-body loss in box potentials.
Phys. Rev. Lett. 134, 153402 (2025)
Cold and ultracold molecules, Open quantum systems & decoherence, Ultracold chemistry, Ultracold collisions, Atoms, Molecules, Ultracold gases
Controlling the Polarization and Vortex Charge of $\gamma $ Photons via Nonlinear Compton Scattering
Research article | Angular momentum of light | 2025-04-17 06:00 EDT
Jing-Jing Jiang, Kai-Hong Zhuang, Jia-Ding Chen, Jian-Xing Li, and Yue-Yue Chen
High-energy vortex $\gamma $ photons have significant applications in many fields. However, their generation and angular momentum manipulation are still great challenges. Here, we first investigated the generation of vortex $\gamma $ photons with controllable spin and orbital angular momenta via nonlinear Compton scattering of two-color counter-rotating circularly polarized ($CP$) laser fields. The radiation probabilities of vortex photons are calculated using the semiclassical approach that resolves angular momenta of emitted photons. We find that the angular momenta transferred to emitted photons are determined by the dominating photon absorption channel, leading to a structured spectrum with alternations in helicity and twist directions. By tuning the relative intensity ratio of the two-color $CP$ laser fields, the polarization and vortex charge of the emitted $\gamma $ photons can be controlled, enabling the generation of $CP$ vortex $\gamma $ photons with a user-defined polarization and topological charge, which may have multiple applications in nuclear physics, astrophysics, particle physics, etc.
Phys. Rev. Lett. 134, 153802 (2025)
Angular momentum of light, Beam code development & simulation techniques, High-order harmonic generation, Laser-cluster interaction, Quantum description of light-matter interaction, Quantum electrodynamics, Scattering theory, Strong electromagnetic field effects, Laser applications, Compton scattering
Experimental Observation of the Motion of Ions in a Resonantly Driven Plasma Wakefield Accelerator
Research article | Beam-plasma instability | 2025-04-17 06:00 EDT
M. Turner et al. (AWAKE Collaboration)
We show experimentally that an effect of motion of ions, observed in a plasma-based accelerator, depends inversely on the plasma ion mass. The effect appears within a single wakefield event and manifests itself as a bunch tail, occurring only when sufficient motion of ions suppresses wakefields. Wakefields are driven resonantly by multiple bunches, and simulation results indicate that the ponderomotive force causes the motion of ions. In this case, the effect is also expected to depend on the amplitude of the wakefields, experimentally confirmed through variations in the drive bunch charge.
Phys. Rev. Lett. 134, 155001 (2025)
Beam-plasma instability, Particle acceleration in plasmas, Plasma acceleration & new acceleration techniques, Plasma-beam interactions, Plasma-particle interactions
Unlocking New Regimes in Fractional Quantum Hall Effect with Quaternions
Research article | Composite fermions | 2025-04-17 06:00 EDT
Mytraya Gattu and J. K. Jain
We demonstrate that formulating the composite-fermion theory of the fractional quantum Hall (FQH) effect in terms of quaternions greatly expands its reach and opens the door into many interesting issues that were previously not amenable to quantitative theoretical investigation. As an illustration, we explore the possibility of a nematic or a charge-density wave instability of the composite-fermion Fermi sea at half-filled Landau level and of the nearby FQH states by looking for a gap closing instability of the neutral magneto-roton excitation. Our quaternion formulation of the FQH effect has been inspired by mathematical developments in the theoretical analyses of gravitational wave modes and cosmic microwave background radiation, where an important role is played by spin-weighted spherical harmonics that are nothing but monopole harmonics appearing in the spherical geometry for the FQH effect.
Phys. Rev. Lett. 134, 156501 (2025)
Composite fermions, Fractional quantum Hall effect, Strongly correlated systems
Shortcuts to Adiabaticity across a Separatrix
Research article | Classical mechanics | 2025-04-17 06:00 EDT
Roi Holtzman, Oren Raz, and Christopher Jarzynski
Shortcuts to adiabaticity are strategies for conserving adiabatic invariants under nonadiabatic (i.e. fast-driving) conditions. Here, we show how to extend classical, Hamiltonian shortcuts to adiabaticity to allow the crossing of a phase-space separatrix—a situation in which a corresponding adiabatic protocol does not exist. Specifically, we show how to construct a time-dependent Hamiltonian that evolves one energy shell to another energy shell across a separatrix. Leveraging this method, we design an erasure procedure whose energy cost bound and fidelity do not depend on the protocol’s duration.
Phys. Rev. Lett. 134, 157201 (2025)
Classical mechanics, Classical statistical mechanics, Thermodynamics of computation, Hamiltonian systems, Adiabatic approximation, Phase space methods
Physical Review X
A Quantum Critical Line Bounds the High Field Metamagnetic Transition Surface in ${\mathrm{UTe}}_{2}$
Research article | Critical phenomena | 2025-04-17 06:00 EDT
Z. Wu, T. I. Weinberger, A. J. Hickey, D. V. Chichinadze, D. Shaffer, A. Cabala, H. Chen, M. Long, T. J. Brumm, W. Xie, Y. Ling, Z. Zhu, Y. Skourski, D. E. Graf, V. Sechovský, M. Vališka, G. G. Lonzarich, F. M. Grosche, and A. G. Eaton
High-field superconductivity in UTe2 is linked to a continuous quantum critical line rather than a single quantum critical point. The findings suggest that metamagnetic fluctuations play a key role in the observed high-field superconductivity.
Phys. Rev. X 15, 021019 (2025)
Critical phenomena, Exotic phases of matter, High magnetic fields, Spin-triplet pairing, Heavy-fermion systems, Unconventional superconductors
Review of Modern Physics
Gas bubble dynamics
Research article | | 2025-04-17 06:00 EDT
Dominique Legendre and Roberto Zenit
The motion of gas bubbles in liquids plays a vital role in numerous natural, industrial, and everyday phenomena. Unlike solid particles, gas bubbles are nearly weightless and highly responsive to forces from the surrounding fluid. Their dynamics are affected by added mass acceleration and deformable surfaces, and also by interactions with turbulent flows, other bubbles, and walls, with liquid rheology and surfactants further influencing their behavior. This review examines the intricate behavior of noncondensable gas bubbles, highlighting key advances over the past 20 years. Key topics include turbulence, non-Newtonian fluids, and electrolytes, offering insights to enhance modeling and guide future research in two-phase flow systems.
Rev. Mod. Phys. 97, 025001 (2025)
arXiv
Strong ergodicity breaking in dynamical mean-field equations for mixed p-spin glasses
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-18 20:00 EDT
Vincenzo Citro, Federico Ricci-Tersenghi
The analytical solution to the out-of-equilibrium dynamics of mean-field spin glasses has profoundly shaped our understanding of glassy dynamics, which take place in many diverse physical systems. In particular, the idea that during the aging dynamics, the evolution becomes slower and slower, but keeps wandering in an unbounded space (a manifold of marginal states), thus forgetting any previously found configuration, has been one of the key hypotheses to achieve an analytical solution. This hypothesis, called weak ergodicity breaking, has recently been questioned by numerical simulations and attempts to solve the dynamical mean-field equations (DMFE). In this work, we introduce a new integration scheme for solving DMFE that allows us to reach very large integration times, $ t=O(10^6)$ , in the solution of the spherical (3+4)-spin model, quenched from close to the mode coupling temperature down to zero temperature. Thanks to this new solution, we can provide solid evidence for strong ergodicity breaking in the out-of-equilibrium dynamics on mixed p-spin glass models. Our solution to the DMFE shows that the out-of-equilibrium dynamics undergo aging, but in a restricted space: the initial condition is never forgotten, and the dynamics takes place closer and closer to configurations reached at later times. During this new restricted aging dynamics, the fluctuation-dissipation relation is richer than expected.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
5 page, 4 figures
Fermi surface and magnetic breakdown in PdGa
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Nico Huber, Ivan Volkau, Alexander Engelhardt, Ilya Sheikin, Andreas Bauer, Christian Pfleiderer, Marc A. Wilde
We study the electronic structure of the chiral semimetal PdGa by means of the de Haas-van Alphen and Shubnikov-de Haas effect. We find that the Fermi surface of PdGa comprises multiple pockets split by spin-orbit coupling. We compare our experimental findings with the band structure calculated ab initio. We demonstrate that the quantum oscillation spectra can be fully understood by considering nodal plane degeneracies at the Brillouin zone boundary and magnetic breakdown between individual Fermi surface pockets. Expanding traditional analysis methods, we explicitly calculate magnetic breakdown frequencies and cyclotron masses while taking into account that extremal breakdown trajectories may reside away from the planes of the single-band orbits. We further analyze high-frequency contributions arising from breakdown trajectories involving multiple revolutions around the Fermi surface which are distinct from conventional harmonic frequencies. Our results highlight the existence of gaps induced by spin-orbit coupling throughout the band structure of PdGa, the relevance of nodal planes on the Brillouin zone boundary, and the necessity for a comprehensive analysis of magnetic breakdown.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Learning transitions in classical Ising models and deformed toric codes
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-18 20:00 EDT
Malte Pütz, Samuel J. Garratt, Hidetoshi Nishimori, Simon Trebst, Guo-Yi Zhu
Conditional probability distributions describe the effect of learning an initially unknown classical state through Bayesian inference. Here we demonstrate the existence of a sharp learning transition for the two-dimensional classical Ising model, all the way from the infinite-temperature paramagnetic state down to the thermal critical state. The intersection of the line of learning transitions and the thermal Ising transition is a novel tricritical point. Our model also describes the effects of weak measurements on a family of quantum states which interpolate between the (topologically ordered) toric code and a trivial product state. Notably, the location of the above tricritical point implies that the quantum memory in the entire topological phase is robust to weak measurement, even when the initial state is arbitrarily close to the quantum phase transition separating topological and trivial phases. Our analysis uses a replica field theory combined with the renormalization group, and we chart out the phase diagram using a combination of tensor network and Monte Carlo techniques. Our results can be extended to study the more general effects of learning on both classical and quantum states.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
5 + 2 pages, 3 + 4 figures
Chiral crossroads in $\mathrm{Ho_3ScO_6}$: a tale of frustration in maple leaf lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Motivated by the recent observation of a uniform vector chirality (UVC) magnetic order in the maple-leaf lattice (MLL) realization $ \mathrm{Ho_3ScO_6}$ via powder neutron scattering experiments, we investigate the classical antiferromagnetic Heisenberg model on the maple-leaf lattice. The MLL features three symmetry-inequivalent nearest-neighbor couplings, $ J_d$ , $ J_t$ , and $ J_h$ . Previous studies, primarily focused on the case where $ J_t = J_h$ , identified a staggered vector chirality (SVC) order. Extending beyond this limit, we demonstrate that the SVC order remains stable across a broad parameter regime. However, we also find that the UVC order cannot emerge from the nearest-neighbor model alone. By introducing a further-neighbor antiferromagnetic interaction, $ J_x$ , we demonstrate that even a weak $ J_x$ can cause a first-order phase transition from SVC to UVC order. Using linear spin wave theory, we compute the dynamical spin structure factor, revealing distinct signatures for SVC and UVC orders that can be probed through inelastic neutron scattering experiments. Additionally, we calculate the specific heat, which exhibits qualitative agreement with the experimental data for $ \mathrm{Ho_3ScO_6}$ . Our findings provide a minimal framework for understanding $ \mathrm{Ho_3ScO_6}$ and related MLL systems, like $ \mathrm{MgMn_3O_7.3H_2O}$ , suggesting avenues for further experimental and theoretical investigations.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
8 pages, 5 figures
Probing viscous regimes of spin transport with local magnetometry
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
It is now well-established, both theoretically and experimentally, that charge transport of metals can be in a hydrodynamic regime in which frequent electron-electron collisions play a significant role. Meanwhile, recent experiments have demonstrated that it is possible to inject spin currents into magnetic insulator films and explore the DC transport properties of spins. Inspired by these developments, we investigate the effect of viscosity, which naturally arises in the hydrodynamic regime, on DC spin transport. We show that viscosity gives rise to a sharp peak in the spatial profile of the out-of-plane stray magnetic field near the spin current injector. We propose that local magnetometers such as SQUIDs and nitrogen-vacancy centers can detect this viscosity-induced structure in the stray magnetic field. We also discuss the relevance of our results to yittrium iron garnet, a ferromagnetic insulator, and to Kagome spin liquids.
Strongly Correlated Electrons (cond-mat.str-el)
Spontaneous symmetry breaking in the Heisenberg antiferromagnet on a triangular lattice
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Bastián Pradenas, Grigor Adamyan, Oleg Tchernyshyov
We present a detailed investigation of an overlooked symmetry structure in non-collinear antiferromagnets that gives rise to an emergent quantum number for magnons. Focusing on the triangular-lattice Heisenberg antiferromagnet, we show that its spin order parameter transforms under an enlarged symmetry group, $ \mathrm{SO(3)_L \times SO(3)_R}$ , rather than the conventional spin-rotation group $ \mathrm{SO(3)}$ . Although this larger symmetry is spontaneously broken by the ground state, a residual subgroup survives, leading to conserved Noether charges that, upon quantization, endow magnons with an additional quantum number – \emph{isospin} – beyond their energy and momentum. Our results provide a comprehensive framework for understanding symmetry, degeneracy, and quantum numbers in non-collinear magnetic systems, and bridge an unexpected connection between the paradigms of symmetry breaking in non-collinear antiferromagnets and chiral symmetry breaking in particle physics.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Symmetry Aspects of Chiral Superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-18 20:00 EDT
Recent developments in theory, synthesis, and experimental probes of quantum systems have revealed many suitable candidate materials to host chiral superconductivity. Chiral superconductors are a subset of unconventional superconductors which break time-reversal symmetry. Time-reversal symmetry breaking is possible given the order parameter’s two-component nature, allowing for a complex relative phase. In this article, we focus on discussing the underlying symmetry aspects that allow for the development of chiral superconductivity. We provide an introductory account of key concepts in group theory and apply these to the classification of order parameters and the generalization of the Landau theory of phase transitions in the context of superconductivity.
Superconductivity (cond-mat.supr-con)
Contemporary Physics 63(2), 71-86 (2022)
Anomalous Electrical Transport in the Kagome Magnet YbFe$_6$Ge$_6$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Weiliang Yao, Supeng Liu, Hodaka Kikuchi, Hajime Ishikawa, Øystein S. Fjellvåg, David W. Tam, Feng Ye, Douglas L. Abernathy, George D. A. Wood, Devashibhai Adroja, Chun-Ming Wu, Chien-Lung Huang, Bin Gao, Yaofeng Xie, Yuxiang Gao, Karthik Rao, Emilia Morosan, Koichi Kindo, Takatsugu Masuda, Kenichiro Hashimoto, Takasada Shibauchi, Pengcheng Dai
Two-dimensional (2D) kagome metals offer a unique platform for exploring electron correlation phenomena derived from quantum many-body effects. Here, we report a combined study of electrical magnetotransport and neutron scattering on YbFe$ 6$ Ge$ 6$ , where the Fe moments in the 2D kagome layers exhibit an $ A$ -type collinear antiferromagnetic order below $ T{\rm{N}} \approx 500$ K. Interactions between the Fe ions in the layers and the localized Yb magnetic ions in between reorient the $ c$ -axis aligned Fe moments to the kagome plane below $ T{\rm{SR}} \approx 63$ K. Our magnetotransport measurements show an intriguing anomalous Hall effect (AHE) that emerges in the spin-reorientated collinear state, accompanied by the closing of the spin anisotropy gap as revealed from inelastic neutron scattering. The gapless spin excitations and the Yb-Fe interaction are able to support a dynamic scalar spin chirality, which explains the observed AHE. Therefore, our study demonstrates spin fluctuations may provide an additional scattering channel for the conduction electrons and give rise to AHE even in a collinear antiferromagnet.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
7 pages, 5 figures, to be published at PRL
Valley Splitting Correlations Across a Silicon Quantum Well
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Jonathan C. Marcks, Emily Eagen, Emma C. Brann, Merritt P. Losert, Tali Oh, John Reily, Christopher S. Wang, Daniel Keith, Fahd A. Mohiyaddin, Florian Luthi, Matthew J. Curry, Jiefei Zhang, F. Joseph Heremans, Mark Friesen, Mark A. Eriksson
Quantum dots in SiGe/Si/SiGe heterostructures host coherent electron spin qubits, which are promising for future quantum computers. The silicon quantum well hosts near-degenerate electron valley states, creating a low-lying excited state that is known to reduce spin qubit readout and control fidelity. The valley energy splitting is dominated by the microscopic disorder in the SiGe alloy and at the Si/SiGe interfaces, and while Si devices are compatible with large-scale semiconductor manufacturing, achieving a uniformly large valley splitting energy across a many-qubit device spanning mesoscopic distances is an outstanding challenge. In this work we study valley splitting variations in a 1D quantum dot array manufactured by Intel. We observe correlations in valley splitting, at both sub-100nm (single gate) and >1{\mu}m (device) lengthscales, that are consistent with alloy disorder-dominated theory and simulation. Our results develop the mesoscopic understanding of Si/SiGe heterostructures necessary for scalable device design.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Physics (quant-ph)
10 pages, 6 figures
Coarsening of binary Bose superfluids: an effective theory
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-18 20:00 EDT
Elisabeth Gliott, Clara Piekarski, Nicolas Cherroret
We derive an effective equation of motion for binary Bose mixtures, which generalizes the Cahn-Hilliard description of classical binary fluids to superfluid systems. Within this approach, based on a microscopic Hamiltonian formulation, we show that the domain growth law $ L(t)\sim t^{2/3}$ observed in superfluid mixtures is not driven by hydrodynamic flows, but arises from the competition between interactions and quantum pressure. The effective theory allows us to derive key properties of superfluid coarsening, including domain growth and Porod’s laws. This provides a new theoretical framework for understanding phase separation in superfluid mixtures.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
Best practices in Quantum Monte Carlo for metal catalysis: CO hydrolysis on Pt(111)
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Hydrogen production as a clean, sustainable replacement for fossil fuels is gathering pace. Research work and prototyping various aspects of hydrogen power is now a priority. Over 90 % of all chemical manufacture uses a solid catalyst. This work describes catalytic selective hydrogen production optimising reactant structure on a model catalyst. Focus is on O-H bond dissociation in format radicals formed after carbon-monoxide is co-adsorbed with water at Pt(111). Finally, hydrogen gas is given off. Many chemical reactions involve bond-dissociation. This process is often the key to rate-limiting reaction steps at solid surfaces. %This is also true for reactions at solid surfaces, in which the dissociation step is often limiting but facilitated in comparison to gas phase reaction channels. Since bond-breaking is poorly described by Hartree-Fock and DFT methods, our embedded active site approach is used. This work demonstrates Quantum Monte Carlo (QMC) methodology using a very simple four primitive-cell layer model, oriented to expose Pt (111). QMC is a stochastic approach to solving the Schr{ö}dinger equation recently came of age for heterogeneous systems involving solids. During hydrolysis of carbon monoxide, initial O-H bond stretch is rate-limiting. This dissociation energy is offset by Pt-H bond formation at the surface. The reactive formate (H-O-C=O) species formed, by initial hydrolysis of CO, also interact with a vicinal Pt. These are subsequently desorbed. They then produce carbon dioxide and hydrogen, with a H-atom dissociated from the formate species and another desorbed at the Pt(111) face.
Our approach allows a high-level configuration interaction (CI) wave-function to be used, expanded in plane-waves and embedded in the metal lattice exposing its close-packed face. The resulting periodic function is used to guide the QMC calculation.
Materials Science (cond-mat.mtrl-sci)
22 pages,2 figures. arXiv admin note: substantial text overlap with arXiv:2212.01823; text overlap with arXiv:2004.10565, arXiv:2202.00542
An Absorption Correction for Reliable Pair-Distribution Functions from Low Energy X-ray Sources
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Yucong Chen, Till Schertenleib, Andrew Yang, Pascal Schouwink, Wendy L. Queen, Simon J.L. Billinge
This paper explores the development and testing of a simple absorption correction model for processing x-ray powder diffraction data from Debye-Scherrer geometry laboratory x-ray experiments. This may be used as a pre-processing step before using PDFgetX3 to obtain reliable pair distribution functions (PDFs). The correction was found to depend only on muD, the product of the x-ray attenuation coefficient and capillary diameter. Various experimental and theoretical methods for estimating muD were explored, and the most appropriate muD values for correction were identified for different capillary diameters and x-ray beam sizes. We identify operational ranges of muD where reasonable signal to noise is possible after correction. A user-friendly software package, this http URL, is presented that can help estimate muD and perform absorption corrections, with a rapid calculation for efficient processing.
Materials Science (cond-mat.mtrl-sci)
Surface charge density wave in UTe2
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Pablo García Talavera, Miguel Águeda Velasco, Makoto Shimizu, Beilun Wu, Georg Knebel, Midori Amano Patino, Gerard Lapertot, Jacques Flouquet, Jean Pascal Brison, Dai Aoki, Youichi Yanase, Edwin Herrera, Isabel Guillamón, Hermann Suderow
The spatially uniform electronic density characteristic of a metal can become unstable at low temperatures, leading to the formation of charge density waves (CDWs). These CDWs, observed in dichalcogenides, cuprates, and pnictides arise from features in the electron and lattice bandstructures that facilitate charge ordering. CDWs are often considered to compete with Kondo screening and are relatively rare in heavy fermion metals. However, the heavy fermion topological superconductor candidate UTe2 presents a notable exception, exhibiting a CDW whose origin remains elusive. Here we report high resolution Scanning Tunneling Microscopy (STM) experiments that reveal the primitive wavevectors of the CDW in UTe2. This allows for a refined identification of the electronic bandstructure regions susceptible to nesting. We demonstrate that the CDW wavevectors are not linked to bulk antiferromagnetic fluctuations that have been connected to other nesting features, indicating a decoupling from the bulk. We propose that surface-induced modifications of the U-5f electronic structure result in an enhancement of electronic interactions specifically at the nesting wavevectors identified here, thereby driving the formation of the observed surface CDW.
Strongly Correlated Electrons (cond-mat.str-el)
Magnetoresistance in ZrSi$X$ ($X=$ S, Se, Te) nodal-line semimetals
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
ShengNan Zhang, Oleg V. Yazyev
We present a comprehensive first-principles study of the magnetoresistance in ZrSi$ X$ ($ X=$ S, Se, Te) topological nodal-line semimetals. Our study demonstrates that all primary features of the experimentally measured magnetoresistance in these materials are captured by our calculations, including the unusual butterfly-shaped anisotropic magnetoresistance. This anisotropic magnetoresistance can be accurately reproduced using the semiclassical Boltzmann transport theory without introducing any information on the topological nature of bands or the concepts of topological phase transition. Considering the complex structure of the Fermi surface in these topological materials, we develop a theoretical description explaining the features observed in magnetoresistance measurements. Additionally, the atypical Hall resistance can be interpreted by the same semiclassical approach. Our findings establish magnetotransport as a powerful tool for analyzing the geometry of the Fermi surface, complementing angle-resolved photoemission spectroscopy and quantum oscillation measurements. This approach is demonstrated to be particularly useful for determining the role of non-trivial topology in transport properties.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 7 figures, Supplemental Material included as ancillary file (+2 pages)
Generalized Neumann’s Principle as a Unified Framework for Fractional Quantum and Conventional Ferroelectricity
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Monolayer In$ 2$ Se$ 3$ exhibits unexpected in-plane polarization, despite having $ C{3v}$ symmetry, a feature that was traditionally considered forbidden by symmetry. To explain this remarkable behavior, Ji et al. proposed the concept of fractional quantum ferroelectricity (FQFE), in which polarization occurs in fractional multiples of a quantum, and argued that this phenomenon violates Neumann’s principle. However, we introduce a generalized form of Neumann’s principle and demonstrate that both FQFE and conventional ferroelectricity can be consistently described within this unified theoretical this http URL propose a method, based on the generalized Neumann’s principle, for the systematic identification of FQFE materials. This approach is not only more straightforward to apply but also offers a clearer conceptual understanding and deeper physical insight compared to previous methods. Using this method, we determine all symmetry-allowed FQFE cases across the 32 crystallographic point this http URL practical applications rely on the ability to control polarization, we further show that FQFE can be effectively switched via coupling with conventional polarization. Using HfZnN$ _2$ as an illustrative example, we reveal the underlying mechanism of this coupling and outline a strategy to identify other materials with similar switching behavior.
Materials Science (cond-mat.mtrl-sci)
Observation of the Axion quasiparticle in 2D MnBi$_2$Te$_4$
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Jian-Xiang Qiu, Barun Ghosh, Jan Schütte-Engel, Tiema Qian, Michael Smith, Yueh-Ting Yao, Junyeong Ahn, Yu-Fei Liu, Anyuan Gao, Christian Tzschaschel, Houchen Li, Ioannis Petrides, Damien Bérubé, Thao Dinh, Tianye Huang, Olivia Liebman, Emily M. Been, Joanna M. Blawat, Kenji Watanabe, Takashi Taniguchi, Kin Chung Fong, Hsin Lin, Peter P. Orth, Prineha Narang, Claudia Felser, Tay-Rong Chang, Ross McDonald, Robert J. McQueeney, Arun Bansil, Ivar Martin, Ni Ni, Qiong Ma, David J. E. Marsh, Ashvin Vishwanath, Su-Yang Xu
In 1978, Wilczek and Weinberg theoretically discovered a new boson-the Axion-which is the coherent oscillation of the $ \theta$ field in QCD. Its existence can solve multiple fundamental questions including the strong CP problem of QCD and the dark matter. However, its detection is challenging because it has almost no interaction with existing particles. Similar $ \theta$ has been introduced to condensed matter and so far studied as a static, quantized value to characterize topology of materials. But the coherent oscillation of $ \theta$ in condensed matter is proposed to lead to new physics directly analogous to the high-energy Axion particle, the dynamical Axion quasiparticle (DAQ). In this paper, we present the direct observation of the DAQ. By combining 2D electronic device with ultrafast pump-probe optics, we manage to measure the magnetoelectric coupling $ \theta$ ($ \theta\propto\alpha$ ) of 2D MnBi$ _2$ Te$ _4$ with sub-picosecond time-resolution. This allows us to directly observe the DAQ by seeing a coherent oscillation of $ \theta$ at ~44 GHz in real time, which is uniquely induced by the out-of-phase antiferromagnetic magnon. Interestingly, in 2D MnBi$ _2$ Te$ _4$ , the DAQ arises from the magnon-induced coherent modulation of Berry curvature. Such ultrafast control of quantum wavefunction can be generalized to manipulate Berry curvature and quantum metric of other materials in ultrafast time-scale. Moreover, the DAQ enables novel quantum physics such as Axion polariton and electric control of ultrafast spin polarization, implying applications in unconventional light-matter interaction and coherent antiferromagnetic spintronics. Beyond condensed matter, the DAQ can serve as a detector of the dark matter Axion particle. We estimate the detection frequency range and sensitivity in the critically-lacking meV regime, contributing to one of the most challenging questions in fundamental physics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Coarse-Grained Force Fields via Rotational Entropy Corrections to Free Energy Landscapes of Diffusing Molecules
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-18 20:00 EDT
The construction of accurate interatomic potentials, and related fields of forces, from equilibrium conformational distributions of molecules is a crucial step in coarse-grained modeling. In this work we show that in order to develop accurate lab-frame force fields that preserve translational and rotational diffusion of a molecule, the observed body-fixed free energy landscape must be corrected for conformation-dependent rotational entropy to isolate the potential energy surface. We further demonstrate that even when the instantaneous effects of the correction are small, the resulting lagged correlations of the modeled force can be greatly altered and hence the correction is especially vital when parameterizing friction coefficients using modeled interatomic potentials.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
9 pages, 6 figures, submitted to PRE
Reentrant phase transition in quasiperiodic photonic waveguides
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Yang Chen, Ze-Zheng Li, Hua-Yu Bai, Shuai-Peng Guo, Tian-Yang Zhang, Xu-Lin Zhang, Qi-Dai Chen, Guang-Can Guo, Fang-Wen Sun, Zhen-Nan Tian, Ming Gong, Xi-Feng Ren, Hong-Bo Sun
Anderson transition in quasiperiodic potentials and the associated mobility edges have been a central focus in quantum simulation across multidisciplinary physical platforms. While these transitions have been experimentally observed in ultracold atoms, acoustic systems, optical waveguides, and superconducting junctions, their interplay between quasiperiodic potential and long-range hopping remains unexplored experimentally. In this work, we report the observation of localization-delocalization transition induced by the hopping between the next-nearest neighboring sites using quasiperiodic photonic waveguides. Our findings demonstrate that increasing the next-nearest hopping strength induces a reentrant phase transition, where the system transitions from an initially extended phase into a localized phase before eventually returning to an extended phase. This remarkable interplay between hopping and quasiperiodic potential in the lattice models provides crucial insights into the mechanism of Anderson transition. Furthermore, our numerical simulation reveals that this phase transition exhibits a critical exponent of $ \nu \simeq 1/3$ , which is experimentally observable for system sizes $ L\sim10^3$ - $ 10^4$ . These results establish a framework for direct observation of the Anderson transition and precise determination of its critical exponents, which can significantly advance our understanding of localization physics in quasiperiodic systems.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quantum Gases (cond-mat.quant-gas), Optics (physics.optics)
16 pages, 5 figures
Boundary criticality in two-dimensional interacting topological insulators
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Yang Ge, Hong Yao, Shao-Kai Jian
We study the boundary criticality in 2D interacting topological insulators. Using the determinant quantum Monte Carlo method, we present the first nonperturbative study of the boundary quantum phase diagram in the Kane-Mele-Hubbard-Rashba model. Our results reveal rich boundary critical phenomena at the quantum phase transition between a topological insulator and an antiferromagnetic insulator, encompassing ordinary, special, and extraordinary transitions. Combining analytical derivation of the boundary theory with unbiased numerically-exact quantum Monte Carlo simulations, we demonstrate that the presence of topological edge states enriches the ordinary transition that renders a continuous boundary scaling dimension and, more intriguingly, leads to a special transition of the Berezinskii-Kosterlitz-Thouless type. Our work establishes a novel framework for the nonperturbative study of boundary criticality in two-dimensional topological systems with strong electron correlations.
Strongly Correlated Electrons (cond-mat.str-el), Statistical Mechanics (cond-mat.stat-mech)
10 pages (6+4), 5 figures (4+1)
Crystal growth, structure and physical properties of quasi-one-dimensional tellurides Fe${4-x}$VTe${4-y}$ ($x=1.01$, $y=0.74$) and V$_{4.64}$Te$_4$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
S. N. Sun, D. Y. Xu, C. L. Shang, B. X. Shi, J. L. Huang, X. J. Gui, Z. C. Sun, J. J. Liu, J. C. Wang, H. X. Zhang, P. Cheng
A new ternary compound Fe$ _{4-x}$ VTe$ _{4-y}$ ($ x=1.01$ , $ y=0.74$ ) with Ti5Te4-type structure is identified. Fe and V atoms tend to occupy different crystallographic positions and form quasi-one-dimensional (quasi-1D) Fe-V chains along the c-axis. Millimeter-sized single crystal of Fe$ _{2.99}$ VTe$ _{3.26}$ (FVT) with slender-stick shape could be grown by chemical vapor transport method which reflects its quasi-1D crystal structure. Magnetization measurements reveal that FVT orders antiferromagnetically below T$ _N$ =93 K with strong easy ab-plane magnetic anisotropy. Although a weak glassy-like behavior appears below 10 K, FVT is dominant by long-range antiferromagnetic order in contrast to the spin-glass state in previously reported isostructural Fe$ _{5}$ Te$ _{4}$ . We also synthesize V$ _{4.64}$ Te$ _4$ with similar quasi-1D V-chains and find it has weak anomalies at 144 K on both resistivity and susceptibility curves. However, no clear evidence is found for the development of magnetic or charge order. X-ray photoelectron spectroscopy and Curie-Weiss fit reveal that the effective moments for Fe$ ^{2+}$ and V$ ^{4+}$ in both compounds have large deviations from the conventional local moment model, which may possibly result from the formation of Fe/V metal-metal bondings. Furthermore the resistivity of both FVT and V$ _{4.64}$ Te$ _4$ exhibits semiconducting-like temperature-dependent behavior but with average values close to typical bad metals, which resembles the transport behavior in the normal state of Fe-based superconductors. These quasi-1D compounds have shown interesting physical properties for future condensed matter physics research.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
19 pages, 5 figures
Accelerated Collapse Kinetics of Charged Polymers in Good Solvent: Role of Counterion Condensation
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-18 20:00 EDT
Susmita Ghosh, Satyavani Vemparala
We investigate the collapse kinetics of charged polymers (polyelectrolytes) induced by counterion condensation using coarse-grained molecular dynamics simulations. Under good solvent conditions, polyelectrolytes above the critical charge density ($ A > A_c$ ) exhibit significantly faster collapse dynamics compared to neutral polymers, with dynamic scaling exponents ($ \nu_c \approx 0.76-0.84$ ) distinctly smaller than those observed for neutral polymers ($ \nu_c \approx 1.44$ ) . This accelerated collapse is driven primarily by three mechanisms: (1) local charge neutralization due to counterion condensation, which facilitates immediate local compaction, (2) screening of long-range electrostatic repulsions, reducing the conformational search space, and (3) bridging interactions mediated by multivalent counterions, enhancing efficient formation of intra-chain contacts. We systematically explore the effects of polymer length, charge density, and counterion valency (monovalent, divalent, and trivalent) on collapse dynamics, demonstrating that increased counterion valency significantly lowers the critical charge density required for collapse and accelerates the collapse process. Our findings highlight the limitations of modeling charged biopolymers using purely neutral coarse-grained models, underscoring the importance of electrostatic interactions and counterion dynamics in determining their kinetic pathways. These insights may aid in better understanding the folding, organization, and dynamics of inherently charged biomolecules, such as proteins and nucleic acids.
Soft Condensed Matter (cond-mat.soft)
Current-driven dynamics of antiferromagnetic domain-wall skyrmions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Wooyon Kim, Jun Seok Seo, Se Kwon Kim
Domain-wall skyrmions are magnetic solitons embedded in a domain wall that are topologically equivalent to skyrmions. Here, we theoretically study antiferromagnetic domain-wall skyrmions and their current-driven motion within the Landau-Lifshitz-Gilbert phenomenology, and verify our findings with micromagnetic simulations. While the skyrmion Hall effect is expected to be suppressed in the current-induced motion of antiferromagnetic domain-wall skyrmions, we observe a finite Hall angle, which originates from the anisotropic spin configuration of domain-wall skyrmions. The skyrmion Hall effect is, however, conditionally suppressed and the motion aligns with the current applied in certain directions, which can be interpreted as principal axes of a domain-wall skyrmion that is easily identified from the symmetry of the spin configuration. Our work on antiferromagnetic domain-wall skyrmions shows that the dynamics of spin textures endowed with multiple soliton characteristics can be unconventional, which is envisaged to enrich the field of topological solitons.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Optimizing low-dissipation Carnot-like thermal devices with heat leak
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-04-18 20:00 EDT
Delimiting the bounds of optimal performance for heat engines (HEs), refrigerators (REs), and heat pumps (HPs) is a central goal in thermodynamics. While low-dissipation (LD) models have proven valuable for this purpose, the role of heat leak in such models has received limited attention. Here, we present a unified framework for LD Carnot-like (CL) HEs, REs, and HPs that incorporates heat leaks, and derive new results for the efficiency at maximum power and the power at maximum efficiency. We further investigate the relationship between the bounds of power at fixed efficiency and efficiency at fixed power, demonstrating that these bounds coincide and are described by identical curves across all thermal devices. Finally, we show that the optimal performance of all three devices can be achieved by optimizing the average entropy production rate over the cycle, a result that holds for any CL device and extends beyond the LD assumption.
Statistical Mechanics (cond-mat.stat-mech)
12 pages, 7 figures
Rare-Event-Induced Ergodicity Breaking in Logarithmic Aging Systems
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-18 20:00 EDT
Chunyan Li, Qingyang Feng, Tianjie Zhou, Haiwen Liu, X. C. Xie
Ergodicity breaking and aging effects are fundamental challenges in out-of-equilibrium systems. Various mechanisms have been proposed to understand the non-ergodic and aging phenomena, possibly related to observations in systems ranging from structural glass and Anderson glasses to biological systems and mechanical systems. While anomalous diffusion described by Levy statistics efficiently captures ergodicity breaking, the origin of aging and ergodicity breaking in systems with ultraslow dynamics remain unclear. Here, we report a novel mechanism of ergodicity breaking in systems exhibiting log-aging diffusion. This mechanism, characterized by increasingly infrequent rare events with aging, yields statistics deviating significantly from Levy distribution, breaking ergodicity as shown by unequal time- and ensemble-averaged mean squared displacements and two distinct asymptotic probability distribution functions. Notably, although these rare events contribute negligibly to statistical averages, they dramatically change the system’s characteristic time. This work lays the groundwork for microscopic understanding of out-of-equilibrium systems and provides new perspectives on glasses and Griffiths-McCoy singularities.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
26 pages, 9 figures, 1 table
Observing Nucleation and Crystallization of Rocksalt LiF from Molten State through Molecular Dynamics Simulations with Refined Machine-Learned Force Field
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Boyuan Xu, Liyi Bai, Shenzhen Xu, Qisheng Wu
Lithium fluoride (LiF) is a critical component for stabilizing lithium metal anode and high-voltage cathodes towards the next-generation high-energy-density lithium this http URL modeling study reported the formation of wurtzite LiF below about 550 K (J. Am. Chem. Soc. 2023, 145, 1327-1333), in contrast to experimental observation of rocksalt LiF under ambient conditions. To address this discrepancy, we employ molecular dynamics (MD) simulations with a refined machine-learned force field (MLFF), and demonstrate the nucleation and crystallization of rocksalt LiF from the molten phase at temperatures below about 800 K. The rocksalt phase remains stable in LiF nanoparticles. Complementary density functional theory (DFT) calculations show that dispersion interactions are essential for correctly predicting the thermodynamic stability of rocksalt LiF over the wurtzite phase on top of the commonly used PBE functional. Furthermore, we show that inclusion of virial stresses–alongside energies and forces–in the training of MLFFs is crucial for capturing phase nucleation and crystallization of rocksalt LiF under the isothermal-isobaric ensemble. These findings underscore the critical role of dispersion interactions in atomistic simulations of battery materials, where such effects are often non-negligible, and highlight the necessity of incorporating virial stresses during the training of MLFF to enable accurate modeling of solid-state systems.
Materials Science (cond-mat.mtrl-sci)
High Breakdown Electric Field (> 5 MV/cm) in UWBG AlGaN Transistors
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Seungheon Shin, Hridibrata Pal, Jon Pratt, John Niroula, Yinxuan Zhu, Chandan Joishi, Brianna A. Klein, Andrew Armstrong, Andrew A. Allerman, Tomás Palacios, Siddharth Rajan
We report on the design and demonstration of ultra-wide bandgap (UWBG) AlGaN-channel metal-insulator heterostructure field effect transistors (HEFTs) for high-power, high-frequency applications. We find that the integration of gate dielectrics and field plates greatly improves the breakdown field in these devices, with state-of-art average breakdown field of 5.3 MV/cm (breakdown voltage > 260 V) with an associated maximum current density of 342 mA/mm, and cut-off frequency of 9.1 GHz. Furthermore, low trap-related impact was observed from minimal gate and drain lag estimated from pulsed I-V characteristics. The reported results provide the potential of UWBG AlGaN HEFTs for the next generation high-power radio frequency applications.
Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph)
14 pages, 10 figures
Rheology of dilute granular gases with hard-core and inverse power-law potentials
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-18 20:00 EDT
Yuria Kobayashi, Shunsuke Iizuka, Satoshi Takada
The kinetic theory of dilute granular gases with hard-core and inverse power-law potentials is developed. The scattering process is studied theoretically, which yields the relative speed and the impact parameter dependence of the scattering angle. The viscosity is derived from the Boltzmann equation and its temperature dependence is plotted. We also perform the direct simulation Monte Carlo to check the validity of the theory.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
4 pages, 4 figures
Ab initio study of anisotropic effects in two-dimensional Fe$_3$GeTe$_2$ using $\bf{k}$-dependent Green’s functions
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Ilya V. Kashin, Sergei N. Andreev
In the present work, we develop the Green’s function apparatus and extend its applicability to the study of microscopic anisotropic effects in real conducting materials. The problem of the previously proposed approaches written in terms of inter-atomic Green’s functions is the presence of a spatial sum over all atoms of the crystal, which greatly complicates their application to systems with itinerant electrons. To provide a solution we derived expressions for magnetic torque vector and Dzyaloshinskii-Moriya interactions based on $ \bf{k}$ -dependent Green’s functions, which allow numerical evaluations with guaranteed stability of spatial sums over the crystal lattice and moreover with much lower computational cost. Approbation of the approaches on the case of Fe$ _3$ GeTe$ _2$ monolayer, which is based on first-principles DFT calculations, confirmed the numerical stability and allowed us to reproduce the characteristic length of experimentally observed collective spin excitations in the domain structure of this promising conducting material.
Materials Science (cond-mat.mtrl-sci)
14 pages, 4 figures
7-Methylquinolinium Iodobismuthate Memristor: Exploring Plasticity and Memristive Properties for Digit Classification in Physical Reservoir Computing
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-04-18 20:00 EDT
Gisya Abdi, Ahmet Karacali, Alif Syafiq Kamarol Zaman, Marlena Gryl, Andrzej Sławek, Aleksandra Szkudlarek, Hirofumi Tanaka, Konrad Szaciłowski
This study investigates 7-methylquinolinium halobismuthates (I, Br, and Cl) in two aspects: (1) their structural and semiconducting properties influenced by anionic composition, and (2) their memristive and plasticity characteristics for neuromorphic and reservoir computing applications. Structural changes induced by halides form low-dimensional halobismuthate fragments, confirmed by crystallographic analysis. Optical band gaps were studied using diffuse reflectance spectroscopy, aligning with density functional theory results. Due to solubility limitations, only bismuth iodide complexes were explored in electronic devices. Current-voltage scans showed pinched hysteresis loops, characteristic of memristors. Conductivity versus temperature study indicates combined ionic and electronic contributions to conductivity of the devices. Given that a memristor can function as a single synapse without the need for programming, aligning with the requirements of neuromorphic computing, the study investigated long-term depression, potentiation, and spike-time-dependent plasticity. As the potentiation-depression plots showed non-linearity with fading memory, these materials can be a good candidate for application in physical reservoir computing. To further assess this material, an electronic device with sixteen gold electrodes was applied, featuring one input and 15 output electrodes deposited on silicon substrate and covered with a layer of studied compound. Basic test to assess the complexity and non-linearity of the devices were conducted through a series of benchmark tasks, including waveform generation, NARMA-2, memory capacity assessment, and noise study under both DC and AC current. The ability of device in MNIST digit classification with 82.26% accuracy and voice classification for digit 2 for six different people with 82 % accuracy has been demonstrated.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Ultrafast dynamics of vibronically dressed core-excitons in graphite: a femtosecond RIXS perspective
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Marco Malvestuto, Beatrice Volpato, Elena Babici, Richa Bhardwaj, Antonio Caretta, Simone Laterza, Fulvio Parmigiani, Michele Manfredda, Alberto Simoncig, Marco Zangrando, Alexander Demidovich, Peter Susnjar, Enrico Massimiliano Allaria, Alexander Darius Brynes, David Garzella, Luca Giannessi, Primoz Rebernik, Filippo Sottocorona, Dino Novko
This study demonstrates one of the first implementations of time-resolved resonant inelastic X-ray scattering (tr-RIXS), marking a seminal extension of RIXS spectroscopy into the ultrafast time domain. By investigating the ultrafast dynamics of vibronically dressed core excitons in graphite using femtosecond X-ray pulses from a Free Electron Laser, we reveal previously inaccessible insights into the transient coupling between core excitons and specific optical phonon modes. Our approach establishes tr-RIXS as a powerful, transformative tool capable of elucidating the intricate interplay between electronic and lattice dynamics, opening new avenues in ultrafast materials research.
Materials Science (cond-mat.mtrl-sci)
9 pages, 3 figures
Nonlinear spin dynamics across Néel phase transition in ferromagnetic/antiferromagnetic multilayers
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
O. Busel, D. Polishchuk, A. Kravets, V. Korenivski
We observe strongly nonlinear spin dynamics in ferro-/antiferro-magnetic multilayers, controlled by the number of bilayers in the system, layer thicknesses, as well as temperature, peaking in magnitude near the Néel point of the antiferromagnetic layers just above room temperature. Well above the Néel transition, the individual ferromagnetic layers are exchange decoupled and resonate independently. As the temperature is lowered toward the Néel point, the ferromagnetic proximity effect through the thin antiferromagnetic spacers transforms the system into a weakly coupled macrospin chain along the film normal, which exhibits pronounced standing spin-wave resonance modes, comparable in intensity to the uniform resonance in the ferromagnetic layers. These findings are supported by our micromagnetic simulations showing clear spin-wave profiles with precessional phase lag along the macrospin chain. Well below the Néel transition, the FeMn layers order strongly antiferromagnetically and exchange-pin the ferromagnetic layers to effectively make the multilayer one macrospin. The appearance and intensity of the high-frequency spin-wave modes can thus be conveniently controlled by thermal gating the multilayer. The nonlinearity in the microwave response of the demonstrated material can approach 100%, large compared to nonlinear materials used in e.g. optics, with second-harmonic generation often at the single percentage level.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 5 figures
Model calculations of the strains associated with surface acoustic waves
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Takuya Kawada, Masashi Kawaguchi, Hiroki Matsumoto, Masamitsu Hayashi
Magnon-phonon coupling has garnered increasing interest in condensed matter physics due to its fertile physics and potential applications in devices with novel functionalities. Surface acoustic waves (SAWs) are commonly employed as a source of coherent acoustic phonons. The strain associated with SAWs couples to magnetization of magnetic materials via magnetoelastic coupling and/or spin-rotation coupling. A typical SAW device is formed on a piezoelectric substrate with anisotropic crystal structure. Since the form of strain depends on the material parameters and structure of the SAW device, it is of vital importance to understand its character. In this paper, we present a comprehensive methodology to numerically calculate the SAW velocity, SAW excitation efficiency, lattice displacement and all strain components associated with SAW. LiNbO$ _3$ is used as a prototypical material system. All quantities depend on the SAW propagation direction with respect to the crystalline axis and on the electrical boundary conditions. In contrast to non-piezoelectric isotropic media, we find that all shear strain components can be induced in LiNbO$ _3$ , with their amplitude and relative phase (with respect to the longitudinal strain) dependent on the propagation direction and the boundary conditions at the LiNbO$ _3$ surface. These results offer a robust foundation for analyzing strain-driven magnon-phonon coupling mechanisms and contribute to designing strain-engineered functional magnonic and phononic devices.
Materials Science (cond-mat.mtrl-sci)
26 pages, 9 figures
Self-consistent random phase approximation and optimized hybrid functionals for solids
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Thomas Pitts, Damian Contant, Maria Hellgren
The random phase approximation (RPA) and the $ GW$ approximation share the same total energy functional but RPA is defined on a restricted domain of Green’s functions determined by a local Kohn-Sham (KS) potential. In this work, we perform self-consistent RPA calculations by optimizing the local KS potential through the optimized effective potential equation. We study a number of solids (C, Si, BN, LiF, MgO, TiO$ _2$ ), and find in all cases a lowering of the total energy with respect to non-self-consistent RPA. We then propose a variational approach to optimize PBE0-type hybrid functionals based on the minimization of the RPA total energy with respect to the fraction of exact exchange used to generate the input KS orbitals. We show that this scheme leads to hybrid functionals with a KS band structure in close agreement with RPA, and with lattice constants of similar accuracy as within RPA. Finally, we evaluate $ G_0W_0$ gaps using RPA and hybrid KS potentials as starting points. Special attention is given to TiO$ _2$ , which exhibits a strong starting-point dependence.
Materials Science (cond-mat.mtrl-sci)
13 pages, 6 figures
Crossover in Electronic Specific Heat near Narrow-Sense Type-III Dirac Cones
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Keita Kishigi, Yasumasa Hasegawa
Two-dimensional massless Dirac fermions exhibit Dirac cones, which are classified into three types: type-I, type-II, and type-III. In both type-I and type-II cones, the energy dispersion is linear in all momentum directions. Type-I cones are characterized by a non-overtilted structure, where the Dirac point serves as a local minimum (maximum) for the upper (lower) band. In contrast, type-II cones exhibit overtilted dispersions, leading to the coexistence of electron and hole pockets. At the critical tilt, the linear energy dispersion vanishes in one momentum direction, corresponding to a type-III Dirac cone. We further define a special case, termed the “narrow-sense” type-III cone, where not only the linear term but also quadratic and higher-order terms vanish, resulting in a completely flat dispersion along one direction. In this work, we numerically investigate the temperature ($ T$ ) -dependence of the electronic specific heat ($ C$ ), as the Dirac cone is continuously tilted from type-I to narrow-sense type-III. A model with particle-hole symmetry is employed to ensure that the chemical potential ($ \mu$ ) remains temperature independent. Our results reveal a notable crossover in $ C$ near narrow-sense type-III, where $ C$ changes from $ C \propto T^{2}$ below the crossover temperature ($ T_{\rm co}$ ) to $ C \propto T^{\frac{1}{2}}$ above $ T_{\rm co}$ . This crossover is attributed to the energy-dependent structure of the density of states. The present findings suggest a feasible approach for experimentally probing the degree of Dirac cone tilting near the narrow-sense type-III limit.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
7 pages, 10 figures, submitted to Phys. Rev .B
Accessing quasi-flat $\textit{f}$-bands to harvest large Berry curvature in NdGaSi
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Anyesh Saraswati, Jyotirmoy Sau, Sudipta Chatterjee, Sandip Kumar Kuila, Bibhas Ghanta, Anup Kumar Bera, Partha Pratim Jana, Manoranjan Kumar, Nitesh Kumar
Bands away from the Fermi energy do not influence the electrical conduction. In typical rare-earth lanthanide compounds, the localized 4$ \textit{f}$ -electrons have a weak effect on the electrical conduction, limiting their influence on the Berry curvature and, hence, the intrinsic anomalous Hall effect. However, a comprehensive study of the magnetic, thermodynamic, and transport properties of single-crystalline NdGaSi, guided by first-principles calculations, reveals a ferromagnetic ground state that induces a splitting of quasi-flat 4$ \textit{f}$ -electronic bands and positions them near the Fermi energy. The observation of an extraordinarily large intrinsic anomalous Hall conductivity of 1165 $ \Omega^{-1}$ cm$ ^{-1}$ implies the direct involvement of localized states in the generation of non-trivial band crossings around the Fermi energy. These results are remarkable when compared to ferrimagnetic NdAlSi, which differs only in a non-magnetic atom (a change in the principal quantum number $ \textit{n}$ of the outer $ \textit{p}$ orbital) with the same number of valence electrons and does not exhibit any measurable anomalous Hall conductivity.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Probing the topological protection of edge states in multilayer tungsten ditelluride with the superconducting proximity effect
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
X. Ballu, Z. Dou, L. Bugaud, R. Delagrange, A. Bernard, Ratnadwip Singha, L. M. Schoop, R. J. Cava, R. Deblock, Sophie Gueron, H. Bouchiat, M. Ferrier
The topology of WTe2, a transition metal dichalcogenide with large spin-orbit interactions, is thought to combine type II Weyl semimetal and second-order topological insulator (SOTI) character. The SOTI character should endow WTe2 multilayer crystals with topologically protected helical states at its hinges, and, indeed, 1D states have been detected thanks to Josephson interferometry. However, the immunity to backscattering conferred to those states by their helical nature has so far not been tested. To probe the topological protection of WTe2 edge states, we have fabricated Superconducting Quantum Interference Devices (SQUIDs) in which the supercurrent through a junction on the crystal edge interferes with the supercurrent through a junction in the bulk of the crystal. We find behaviors ranging from a Symmetric SQUID pattern to asymmetric SQUID patterns, including one in which the modulation by magnetic field reveals a sawtooth-like supercurrent versus phase relation for the edge junction, demonstrating that the supercurrent at the edge is carried by ballistic channels over 600 nm, a tell-tale sign of the SOTI character of WTe2.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Main text and Supplementary Material
Long-wavelength optical lattices from optical beatnotes: theory and applications
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-18 20:00 EDT
Tommaso Petrucciani, Andrea Santoni, Chiara Mazzinghi, Dimitrios Trypogeorgos, Francesco Minardi, Marco Fattori, Michele Modugno
We present a theoretical analysis of Beat-Note Superlattices (BNSLs), a recently demonstrated technique for generating periodic trapping potentials for ultracold atomic clouds, with arbitrarily large lattice spacings while maintaining interferometric stability. By combining two optical lattices with slightly different wavelengths, a beatnote intensity pattern is formed, generating, for low depths, an effective lattice potential with a periodicity equal to the wavelength associated to the difference between the wavevectors of the two lattices. We study the range of lattice depths and wavelengths under which this approximation is valid and investigate its robustness against perturbations. We present a few examples where the use of BNSLs could offer significant advantages in comparison to well established techniques for the manipulation of ultracold atomic gases. Our results highlight the potential of BNSLs for quantum simulation, atom interferometry, and other applications in quantum technologies.
Quantum Gases (cond-mat.quant-gas), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
18 pages, 13 figure
Scattering of a Dirac particle by a Berry phase domain wall
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Lassaad Mandhour, Farah Bouhadida, Frédéric Piéchon
Massless Dirac particles are characterized by an effective pseudospin-momentum locking, which is the origin of the peculiar scattering properties of Dirac particles through potential barriers. This pseudospin-momentum locking also governs the quantum geometric properties (such as the Berry phase and Berry curvature) of Dirac particles. In the present work, we demonstrate that a domain wall separating two regions with distinct quantum geometric properties can serve as an alternative to potential barriers. Specifically, using the three-band $ \alpha-T_3$ model of two-dimensional Dirac particles, we show that a Berry phase domain wall results in partial reflection and transmission of the Dirac particles, despite the fact that the incident and refracted momenta are identical.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 7 figures
A scaling relation of vortex-induced rectification effects in a superconducting thin-film heterostructure
New Submission | Superconductivity (cond-mat.supr-con) | 2025-04-18 20:00 EDT
Yusuke Kobayashi, Junichi Shiogai, Tsutomu Nojima, Jobu Matsuno
Supercurrent rectification, nonreciprocal response of superconducting properties sensitive to the polarity of bias and magnetic field, has attracted growing interest as an ideal diode. While the superconducting rectification effect is a consequence of the asymmetric vortex pinning, the mechanisms to develop its asymmetric potentials have been a subject of ongoing debate, mainly focusing on microscopic breaking of spatial inversion symmetry and macroscopic imbalance of the sample structure. Here, we report on comparative study of the superconducting diode effect and nonreciprocal resistance in a superconducting Fe(Se,Te)/FeTe heterostructure. In normal state, we observe finite nonreciprocal resistance as a hallmark of the spin-orbit interaction with structural inversion asymmetry. In the superconducting state, we find that the strongly enhanced nonreciprocal coefficient in transition regime is directly coupled to the superconducting diode efficiency through a universal scaling law, indicating the role of spin-momentum-locked state on the asymmetric pinning potential. Our findings, providing a unified picture of the superconducting rectification, pave the way for functionalizing superconducting diode devices.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
32 pages, 4 figures
A particle-based approach for the prediction of grain microstructures in solidification processes
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Salem Mosbah, Rodrigo Gómez Vázquez, Constantin Zenz, Damien Tourret, Andreas Otto
Grain microstructures are crucial to the mechanical properties, performance, and often lifetime of metallic components. Hence, the prediction of grain microstructures emerging from solidification processes at relevant macroscopic scale is essential to the design or optimization of new alloys and processing conditions. Yet, despite the broad range of multi-scale models proposed so far, all of them suffer from computational limitations, such that advances from computational and algorithm perspectives remain needed. Here, we present a novel approach for tracking crystallographic solidification grain envelopes capable of predicting competitive growth scenarios and columnar-to-equiaxed transitions for stationary grains. The model relies on classical assumptions and equations in use in several broadly used and thoroughly validated approaches (e.g. cellular automata). Yet, our approach defines the grain envelope using Lagrangian particles and tracks their evolution using an algorithm and an implementation relying on scalable libraries and using modern CPU/GPU architectures. The model is used to simulate several benchmarks of increasing complexity, and the results are compared to analytical, experimental, and numerical results from literature for the purpose of model validation. To highlight the applicability to real-world processes and the possibility of coupling the model with existing physics-based simulation tools, the model is also (one-way) coupled with a multiphysics laser-material-interaction model to simulate competitive grain growth during laser beam welding of steel.
Materials Science (cond-mat.mtrl-sci)
Frustrated kagome-lattice bilayer quantum Heisenberg antiferromagnet
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Dmytro Yaremchuk, Taras Hutak, Vasyl Baliha, Taras Krokhmalskii, Oleg Derzhko, Jürgen Schnack, Johannes Richter
We consider the $ S=1/2$ antiferromagnetic Heisenberg model on a frustrated kagome-lattice bilayer with strong nearest-neighbor interlayer coupling and examine its low-temperature magnetothermodynamics using a mapping onto a rhombi gas on the kagome lattice. Besides, we use finite-size numerics to illustrate the validity of the classical lattice-gas description. Among our findings there are i) the absence of an order-disorder phase transition and ii) the sensitivity of the specific heat at low temperatures to the shape of the system just below the saturation magnetic field even in the thermodynamic limit.
Strongly Correlated Electrons (cond-mat.str-el)
18 pages, 12 figures
Photoinduced magnetic phase transitions in the cubic Kondo-lattice model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Ryo Hamano, Masahito Mochizuki
We theoretically study photoinduced magnetic phase transitions and their dynamical processes in the Kondo-lattice model on a cubic lattice. It is demonstrated that light irradiation gives rise to magnetic phase transitions from the ground-state ferromagnetic state to a three-dimensional antiferromagnetic state as a nonequilibrium steady state in the photodriven system. This phase transition occurs as a consequence of the formation of pseudo half-filling band occupation via the photoexcitation and relaxation of electrons, where all the electron states constituting the lower band separated from the upper band by an exchange gap are partially but nearly uniformly occupied. We also find that several types of antiferromagnetic correlations, e.g., A-type and C-type antiferromagnetic correlations, appear in a transient state of the dynamical phase transition. By calculating magnon spectra for the photodriven system, we argue that the instability to the A-type or C-type antiferromagnetic state occurs in the ferromagnetic ground state as a softening of the magnon band dispersion at corresponding momentum points depending on the light polarization. Our findings provide important insights into the understanding of photoinduced magnetic phase transitions in the three-dimensional Kondo-lattice magnets.
Strongly Correlated Electrons (cond-mat.str-el)
27 pages, 14 figures
Switching of an antiferromagnet controlled by spin canting in a laser-induced hidden phase
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
A. V. Kuzikova, N. A. Liubachko, S. N. Barilo, A. V. Sadovnikov, R. V. Pisarev, A. M. Kalashnikova
During laser-induced phase transitions, fast transformations of electronic, atomic, and spin configurations often involve emergence of hidden and metastable phases. Being inaccessible under any other stimuli, such phases are indispensable for unveiling mechanisms and controlling the transitions. We experimentally explore spin kinetics during ultrafast first-order 90$ ^{\circ}$ spin-reorientation (SR) transition in a canted antiferromagnet Fe$ _3$ BO$ _6$ , and reveal that the transition is controlled by the canting between the magnetic sublattices. Laser-induced perturbation of the Dzyaloshinskii-Moriya interaction results in a change of the intersublattice canting within first picoseconds, bringing Fe$ _3$ BO$ _6$ to a hidden phase. Once this phase emerges, laser-induced heating activates precessional 90$ ^\circ$ spin switching. Combination of the spin canting and heating controls the final spin configuration comprising coexisting initial and switched phases. Extended phase coexistence range is in a striking contrast to the narrow SR transition in Fe$ _3$ BO$ _6$ induced by conventional heating.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
5 pages, 4 figures, 1 supplementary materials file
Osmolyte-Modulated Differential Capacitance and Disjoining Pressure for Nanoconfined Electrolytes: A Modified Poisson-Boltzmann Theory
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-18 20:00 EDT
Victoria A. Vasileva, Petr E. Brandyshev, Yury A. Budkov
This study employs modified Poisson-Boltzmann theory to systematically investigate the influence of zwitterionic osmolyte additives to an electrolyte solution on disjoining pressure and electric differential capacitance within charged slit-like nanopores with conductive walls. We demonstrate that increasing concentrations of zwitterionic osmolytes result in a marked synergistic enhancement of both disjoining pressure and differential capacitance, highlighting their dual role in improving supercapacitor performance. The insights gained underscore the unique capabilities of zwitterionic osmolytes as multifunctional additives for fine-tuning the properties of electric double layers, thereby bridging the gap between capacitive efficiency and electrode longevity.
Soft Condensed Matter (cond-mat.soft)
Unraveling the thermodynamics and mechanism behind the lowering of reduction temperatures in oxide mixtures
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Shiv Shankar, Barak Ratzker, Alisson Kwiatkowski da Silva, Tim M. Schwarz, Hans Brouwer, Baptiste Gault, Yan Ma, Dierk Raabe
Hydrogen-based direct reduction offers a sustainable pathway to decarbonize the metal production industry. However, stable metal oxides, like Cr$ _2$ O$ _3$ , are notoriously difficult to reduce, requiring extremely high temperatures (above 1300 $ ^\circ$ C). Herein, we show how reducing mixed oxides can be leveraged to lower hydrogen-based reduction temperatures of stable oxides and produce alloys in a single process. Using a newly developed thermodynamic framework, we predict the precise conditions (oxygen partial pressure, temperature, and oxide composition) needed for co-reduction. We showcase this approach by reducing Cr$ _2$ O$ _3$ mixed with Fe$ _2$ O$ _3$ at 1100 $ ^\circ$ C, significantly lowering reduction temperatures (by $ \geq$ 200 $ ^\circ$ C). Our model and post-reduction atom probe tomography analysis elucidate that the temperature-lowering effect is driven by the lower chemical activity of Cr in the metallic phase. This strategy achieves low-temperature co-reduction of mixed oxides, dramatically reducing energy consumption and CO$ _2$ emissions, while unlocking transformative pathways toward sustainable alloy design.
Materials Science (cond-mat.mtrl-sci)
Tensor-monopole-induced topological boundary effects in four-dimensional acoustic metamaterials
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Qingyang Mo, Shanjun Liang, Cuicui Lu, Jie Zhu, Shuang Zhang
Gauge field theory provides the mathematical and conceptual framework to describe and understand topological singularities such as Weyl points and magnetic monopoles. While singularities associated with vector electromagnetic gauge fields have been well-studied, those of higher-form tensor gauge fields, like the four-dimensional (4D) tensor monopoles predicted by string theory, have remained largely theoretical or limited to experimental demonstration in pure synthetic dimensions, thereby not allowing investigations of the associated boundary effects. Here, we present a 4D system with tensor monopoles using engineered acoustic metamaterials. Our momentum space combines three real momentum dimensions and a geometric parameter as the fourth. By varying this fourth momentum, we experimentally reveal two distinct topological surface states in 3D subsystems: Fermi-arc surface states in a gapless subsystem and Dirac-cone surface states in a gapped subsystem. Our work introduces a novel platform for exploring new topological structures associated with tensor gauge field and topological phenomena in higher dimensions.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
X-ray linear dichroic orientation tomography: reconstruction of nanoscale three-dimensional orientation fields
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Andreas Apseros, Valerio Scagnoli, Manuel Guizar-Sicairos, Laura J. Heyderman, Johannes Ihli, Claire Donnelly
Properties in crystalline and ordered materials tend to be anisotropic, with their orientation affecting the macroscopic behavior and functionality of materials. The ability to image the orientation of anisotropic material properties in three dimensions (3D) is fundamental for the understanding and functionality-driven development of novel materials. With the development of X ray linear dichroic orientation tomography (XL DOT), it is now possible to non-destructively map three-dimensional (3D) orientation fields in micrometer-sized samples. In this work, we present the iterative, gradient-based reconstruction algorithm behind XL DOT that can be used to map orientations based on linear dichroism in 3D. As linear dichroism can be exhibited by a broad spectrum of materials, XL DOT can be used to map, for example, crystal orientations as well as ferroic alignment, such as ferroelectric and antiferromagnetic order. We demonstrate the robustness of this technique for orientation fields that exhibit smoothly varying and granular configurations, and subsequently identify and discuss optimal geometries for experimental data acquisition and optimal conditions for the reconstruction. We anticipate that this technique will be instrumental in enabling a deeper understanding of the relationship between material structures and their functionality, quantifying, for example, the orientation of charge distributions and magnetic anisotropies at the nanoscale in a wide variety of systems - from functional to energy materials.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Motion of ferrodark solitons in harmonically trapped superfluids: spin corrections and emergent quartic potentials exhibiting symmetry breaking
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-18 20:00 EDT
We propose a framework for topological soliton dynamics in trapped spinor superfluids, decomposing the force acting on the soliton by the surrounding fluid into the buoyancy force and spin-corrections arising from the density depletion at soliton core and the coupling between the orbital motion and the spin mixing, respectively. For ferrodark solitons (FDSs) in spin-1 Bose-Einstein Condensates (BECs), the spin correction enables mapping the FDS motion in a harmonic trap to the atomic-mass particle dynamics in an emergent quartic potential. Initially placing a type-I FDS near the trap center, a single-sided oscillation happens, which maps to the particle moving around a local minimum of the emergent double-well potential. As the initial distance of a type-II FDS from the trap center increases, the motion exhibits three regimes: trap-centered harmonic and anharmonic, followed by single-sided oscillations. Correspondingly the emergent quartic potential undergoes symmetry breaking, transitioning from a single minimum to a double-well shape, where particle motion shifts from oscillating around the single minimum to crossing between two minima via the local maximum, then the motion around one of the two minima. In a hard-wall trap with linear potential, the FDS motion maps to a harmonic oscillator.
Quantum Gases (cond-mat.quant-gas), Pattern Formation and Solitons (nlin.PS)
4 pages, 2 figures
Hopf Exceptional Points
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-04-18 20:00 EDT
Tsuneya Yoshida, Emil J. Bergholtz, Tomáš Bzdušek
Exceptional points at which eigenvalues and eigenvectors of non-Hermitian matrices coalesce are ubiquitous in the description of a wide range of platforms from photonic or mechanical metamaterials to open quantum systems. Here, we introduce a class of Hopf exceptional points (HEPs) that are protected by the Hopf invariants (including the higher-dimensional generalizations) and which exhibit phenomenology sharply distinct from conventional exceptional points. Saliently, owing to their $ \mathbb{Z}2$ topological invariant related to the Witten anomaly, three-fold HEPs and symmetry-protected five-fold HEPs act as their own ``antiparticles”. Furthermore, based on higher homotopy groups of spheres, we predict the existence of multifold HEPs and symmetry-protected HEPs with non-Hermitian topology captured by a range of finite groups (such as $ \mathbb{Z}3$ , $ \mathbb{Z}{12}$ , or $ \mathbb{Z}{24}$ ) beyond the periodic table of Bernard-LeClair symmetry classes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optics (physics.optics), Quantum Physics (quant-ph)
8+3pages, 4+1figures
Magnetism-Enhanced Strong Electron-Phonon Coupling in Infinite-Layer Nickelate
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Ruiqi Zhang, Yanyong Wang, Manuel Engel, Christopher Lane, Henrique Miranda, Lin Hou, Sugata Chowdhury, Bahadur Singh, Bernardo Barbiellini, Jian-Xin Zhu, Robert S. Markiewicz, E. K. U. Gross, Georg Kresse, Arun Bansil, Jianwei Sun
Intriguing analogies between the nickelates and the cuprates provide a promising avenue for unraveling the microscopic mechanisms underlying high-$ T_c$ superconductivity. While electron correlation effects in the nickelates have been extensively studied, the role of electron-phonon coupling (EPC) remains highly controversial. Here, by taking pristine LaNiO$ 2$ as an exemplar nickelate, we present an in-depth study of EPC for both the non-magnetic (NM) and the $ C$ -type antiferromagnetic ($ C$ -AFM) phase using advanced density functional theory methods without invoking $ U$ or other free parameters. The weak EPC strength $ \lambda$ in the NM phase is found to be greatly enhanced ($ \sim$ 4$ \times$ ) due to the presence of magnetism in the $ C$ -AFM phase. This enhancement arises from strong interactions between the flat bands associated with the Ni-3$ d{z^2}$ orbitals and the low-frequency phonon modes driven by the vibrations of Ni and La atoms. The resulting phonon softening is shown to yield a distinctive kink in the electronic structure around 15 meV, which would provide an experimentally testable signature of our predictions. Our study highlights the critical role of local magnetic moments and interply EPC in the nickelate.
Strongly Correlated Electrons (cond-mat.str-el), Superconductivity (cond-mat.supr-con)
11 pages, 4 figures
Quantum-gas microscopy of the Bose-glass phase
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-18 20:00 EDT
Lennart Koehn, Christopher Parsonage, Callum W. Duncan, Peter Kirton, Andrew J. Daley, Timon Hilker, Elmar Haller, Arthur La Rooij, Stefan Kuhr
Disordered potentials fundamentally alter the transport properties and coherence of quantum systems. They give rise to phenomena such as Anderson localization in non-interacting systems, inhibiting transport. When interactions are introduced, the interplay with disorder becomes significantly more complex, and the conditions under which localization can be observed remain an open question. In interacting bosonic systems, a Bose glass is expected to emerge at low energies as an insulating yet compressible state without long-range phase coherence. While originally predicted to occur as a ground-state phase, more recent studies indicate that it exists at finite temperature. A key open challenge has been the direct observation of reduced phase coherence in the Bose-glass regime. In this study, we utilize ultracold bosonic atoms in a quantum-gas microscope to probe the emergence of the Bose-glass phase in a two-dimensional square lattice with a site-resolved, reproducible disordered potential. We identify the phase through in-situ distribution and particle fluctuations, via a local measurement of the Edwards-Anderson parameter. To measure the short-range phase coherence in the Bose glass, we employ Talbot interferometry in combination with single-atom-resolved detection. Finally, by driving the system in and out of the Bose-glass phase, we observe signatures for non-ergodic behavior.
Quantum Gases (cond-mat.quant-gas), Disordered Systems and Neural Networks (cond-mat.dis-nn), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)
Design Topological Materials by Reinforcement Fine-Tuned Generative Model
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Haosheng Xu, Dongheng Qian, Zhixuan Liu, Yadong Jiang, Jing Wang
Topological insulators (TIs) and topological crystalline insulators (TCIs) are materials with unconventional electronic properties, making their discovery highly valuable for practical applications. However, such materials, particularly those with a full band gap, remain scarce. Given the limitations of traditional approaches that scan known materials for candidates, we focus on the generation of new topological materials through a generative model. Specifically, we apply reinforcement fine-tuning (ReFT) to a pre-trained generative model, thereby aligning the model’s objectives with our material design goals. We demonstrate that ReFT is effective in enhancing the model’s ability to generate TIs and TCIs, with minimal compromise on the stability of the generated materials. Using the fine-tuned model, we successfully identify a large number of new topological materials, with Ge$ _2$ Bi$ _2$ O$ _6$ serving as a representative example–a TI with a full band gap of 0.26 eV, ranking among the largest known in this category.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
Quantitative measurements of transverse thermoelectric generation and cooling performances in SmCo$5$/Bi${0.2}$Sb$_{1.8}$Te$_3$-based artificially tilted multilayer module
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-04-18 20:00 EDT
Masayuki Murata, Fuyuki Ando, Takamasa Hirai, Hiroto Adachi, Ken-ichi Uchida
The transverse thermoelectric generation and cooling performances in a thermopile module composed of recently developed SmCo$ _5$ /Bi$ _{0.2}$ Sb$ _{1.8}$ Te$ _3$ artificially tilted multilayers are evaluated quantitatively. When a large temperature difference of 405 $ ^\circ$ C is applied to the SmCo$ _5$ /Bi$ _{0.2}$ Sb$ _{1.8}$ Te$ _3$ -based module, the open-circuit voltage and output power reach 0.51 V and 0.80 W, respectively, where the corresponding maximum power density is 0.16 W/cm$ ^2$ . The maximum energy conversion efficiency for our module in this condition is experimentally determined to be 0.92%. Under the cooling operation, the same module exhibits the maximum temperature difference of 9.0 $ ^\circ$ C and heat flow at the cold side of 1.6 W. Although these values are lower than the ideal thermoelectric performance expected from the material parameters due to the imperfections associated with modularization, the systematic investigations reported here clarify a potential of the SmCo$ _5$ /Bi$ _{0.2}$ Sb$ _{1.8}$ Te$ _3$ artificially tilted multilayers as thermoelectric generators and cooling devices.
Materials Science (cond-mat.mtrl-sci)
12 pages, 4 figures
Topological defect engineering enables size and shape control in self-assembly
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-18 20:00 EDT
Lara Koehler, Markus Eder, Christoph Karfusehr, Vincent Ouazan-Reboul, Pierre Ronceray, Friedrich C. Simmel, Martin Lenz
The self-assembly of complex structures from engineered subunits is a major goal of nanotechnology, but controlling their size becomes increasingly difficult in larger assemblies. Existing strategies present significant challenges, among which are the use of multiple subunit types or the precise control of their shape and mechanics. Here we introduce an alternative approach based on identical subunits whose interactions promote crystals, but also favor crystalline defects. We theoretically show that topological restrictions on the scope of these defects in large assemblies imply that the assembly size is controlled by the magnitude of the defect-inducing interaction. Using DNA origami, we experimentally demonstrate both size and shape control in two-dimensional disk- and fiber-like assemblies. Our basic concept of defect engineering could be generalized well beyond these simple examples, and thus provide a broadly applicable scheme to control self-assembly.
Soft Condensed Matter (cond-mat.soft)
7 pages, 4 figures, 36 pages of supplementary information
Instability and stress fluctuations of a probe driven through a worm-like micellar fluid
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-04-18 20:00 EDT
Abhishek Ghadai, Pradip Kumar Bera, Sayantan Majumdar
A particle moving through a worm-like micellar fluid (WLM) shows instability and large fluctuations beyond a threshold. Despite many detailed studies, a direct measurement of the time-dependent stress on the probe particle remains unexplored. To address this, we have designed a measuring geometry coupled with a commercial rheometer to study the dynamics of a cylindrical probe through a WLM system of 2 wt.% cetyltrimethyl ammonium tosylate(CTAT) + 100 mM sodium chloride(NaCl) for a wide range of velocity and stress scales. We map out the in-situ velocity distribution using particle imaging velocimetry. Beyond a certain velocity threshold, we observe large stress fluctuation events with gradual stress build-up followed by sudden stress drop indicating the storage and release of elastic energy. The length scale constructed from the stress build-up time scale and the probe’s velocity match the length scale of extensile deformation in the sample just before the stress drop, further confirming the strong correlation of such storage and release of energy with the unstable motion of the probe. Interestingly, despite their significant difference in magnitudes, the Weissenberg number ($ Wi$ ) for the onset of flow instability obtained from the shear and extensile components remains almost the same. We also find that the turbulent motion of the probe at higher $ Wi$ results from the complex mixing of the stick-slip events originating from the partial release of the stored elastic energy. Further, we show that the magnitude of the stick-slip events depends on the detailed micellar structure and dynamics controlled by salt concentration and temperature.
Soft Condensed Matter (cond-mat.soft)
SI embedded (including the link for movie files)
Many-body cages: disorder-free glassiness from flat bands in Fock space, and many-body Rabi oscillations
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-04-18 20:00 EDT
Tom Ben-Ami, Markus Heyl, Roderich Moessner
We identify the many-body counterpart of flat bands, which we call many-body caging, as a general mechanism for non-equilibrium phenomena such as a novel type of glassy eigenspectrum order and many-body Rabi oscillations in the time domain. We focus on constrained systems of great current interest in the context of Rydberg atoms and synthetic or emergent gauge theories. We find that their state graphs host motifs which produce flat bands in the many-body spectrum at a particular set of energies. Basis states in Fock space exhibit Edwards-Anderson type parameters in the absence of quenched disorder, with an intricate, possibly fractal, distribution over Fock space which is reflected in a distinctive structure of a non-vanishing post-quench long-time Loschmidt echo, an experimentally accessible this http URL general, phenomena familiar from single-particle flat bands manifest themselves in characteristic many-body incarnations, such as a reentrant `Anderson’ delocalisation, offering a rich ensemble of experimental signatures in the abovementioned quantum simulators. The variety of single-particle flat band types suggests an analogous typology–and concomitant phenomenological richness to be explored–of their many-body counterparts.
Quantum Gases (cond-mat.quant-gas), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
Giant nematic response of the incommensurate charge density wave in the nickel-pnictide Ba$_{1-x}$Sr$_x$Ni$_2$As$_2$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Thomas Johnson, Sangjun Lee, Camille Bernal-Choban, Xuefei Guo, Stella Sun, John Collini, Christopher Eckberg, Johnpierre Paglione, Rafael M. Fernandes, Eduardo Fradkin, Peter Abbamonte
Electron nematicity-the breaking of rotational symmetry while preserving translational symmetry-is the quantum analogue of classical nematic liquid crystals. First predicted in 1998, electronic nematicity has been established in a variety of materials, including two-dimensional electron gases (2DEGs) in magnetic fields, copper-oxide superconductors, and Fe-based superconductors. A long-standing open question is what physical mechanisms drive electronic nematic order. In BaFe$ _2$ As$ _2$ and highly underdoped YBa$ _2$ Cu$ _3$ O$ _{6+y}$ , strong evidence suggests that nematicity arises from vestigial spin-density-wave (SDW) order. However, evidence for nematicity associated with charge-density-wave (CDW) order has been less conclusive, particularly in systems near a superconducting state. Here, we present direct evidence for CDW-driven nematic fluctuations in the pnictide superconductor Ba$ _{1-x}$ Sr$ _x$ Ni$ _2$ As$ _2$ (BSNA), a Ni-based homologue of Fe-based superconductors that exhibits CDW rather than SDW order. Previous elastoresistance studies have shown that BSNA displays a large nematic susceptibility-linked to a six-fold enhancement of superconductivity-within a region of the phase diagram occupied by an incommensurate CDW. Using x-ray scattering under uniaxial strain, we demonstrate that even minimal strain levels ($ \epsilon \sim 10^{-4}$ ) significantly break the fourfold symmetry of the CDW. Within a Ginzburg-Landau framework, we define a nematic susceptibility based on the asymmetric response of symmetry-related CDW superlattice reflections, showing strong agreement with elastoresistivity measurements. Our study provides the first clear demonstration of a direct link between charge order and a nematic state, offering key insights into the intertwined superconducting phases of these materials.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Topologically enabled superconductivity: possible implications for rhombohedral graphene
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-04-18 20:00 EDT
Francesca Paoletti, Daniele Guerci, Giorgio Sangiovanni, Urban F.P. Seifert, Elio J. König
We present a topological mechanism for superconductivity emerging from Chern-2 insulators. While, naively, time-reversal symmetry breaking is expected to prevent superconductivity, it turns out that the opposite is the case: An explicit model calculation for a generalized attractive-U Haldane-Hubbard model demonstrates that superconductivity is only stabilized near the quantum anomalous Hall state, but not near a trivial, time-reversal symmetric band insulator. As standard Bardeen-Cooper-Schrieffer-like mean-field theory fails to capture any superconducting state, we explain this using an effective fractionalized field theory involving fermionic chargeons, bosonic colorons and an emergent U(1) gauge field. When the chargeons form a gapped topological band structure, the proliferation of single monopoles of this gauge field is forbidden. However, long-ranged monopole-antimonopole correlations emerge, and we argue that those correspond to superconducting order. Using random phase approximation on top of extensive slave-rotor mean-field calculations we characterize coherence length and stiffness of the superconductor. Thereby, we deduce the phase diagram in parameter space and furthermore discuss the effect of doping, temperature and an external magnetic field. We complement the fractionalized theory with calculations using an effective spin model and Gutzwiller projected wavefunctions. While mostly based on a simple toy model, we argue that our findings contribute to a better understanding of superconductivity emerging out of spin- and valley polarized rhombohedral graphene multilayers in a parameter regime with nearby quantum anomalous Hall insulators.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Superconductivity (cond-mat.supr-con)