CMP Journal 2025-05-23
Statistics
Nature Nanotechnology: 1
Physical Review Letters: 10
Physical Review X: 2
arXiv: 62
Nature Nanotechnology
Supramolecular polymerization through rotation of light-driven molecular motors
Original Paper | Molecular machines and motors | 2025-05-22 20:00 EDT
Philippe Schiel, Mounir Maaloum, Emilie Moulin, Irina Nyrkova, Alexander Semenov, Damien Dattler, Lou-Ann Accou, Anastasia Christoulaki, Eric Buhler, Rémi Plamont, Jean-Marie Lehn, Nicolas Giuseppone
Molecular motors can act on their environment through their unique ability to generate non-reciprocal autonomous motions at the nanoscale. Although their operating principles are now understood, artificial molecular motors have yet to demonstrate their general capacity to confer novel properties on (supra)molecular systems and materials. Here we show that amphiphilic light-driven molecular motors can adsorb onto an air‒water interface and form Langmuir monolayers upon compression. By irradiation with ultraviolet light, the surface pressure isotherms of these films reveal a drastic shift toward a smaller molecular area as a consequence of motor activation. We explain this counterintuitive phenomenon by the rotation-induced supramolecular polymerization of amphiphilic motors through a non-thermal annealing process to escape a kinetically trapped amorphous state. The effect is limited by the maximum torque the molecular motor can deliver (~10 pN nm) and leads to the formation of highly organized patterns. This serendipitous discovery highlights the opportunities offered by molecular motors to control supramolecular polymerization for the design of innovative materials.
Molecular machines and motors, Supramolecular polymers
Physical Review Letters
Experimental Implementation of Dimension-Dependent Contextuality Inequality
Research article | Quantum correlations in quantum information | 2025-05-22 06:00 EDT
Emil Håkansson, Amelie Piveteau, Alban Seguinard, Sadiq Muhammad, Mohamed Bourennane, Otfried Gühne, and Martin Plávala
We present a derivation and experimental implementation of a dimension-dependent contextuality inequality to certify both the quantumness and dimensionality of a given system. Existing methods for certification of the dimension of a quantum system can be cheated by using larger classical systems, creating a potential loophole in these benchmarks, or can in practice only be evaluated assuming pure quantum states. Our approach uses contextuality inequalities that cannot be violated by classical systems thus closing the previous loopholes. We validate this framework experimentally with photons, observing violations of a CHSH-based contextuality inequality and surpassing the qutrit bound of the ${\mathrm{CGLMP}}_{4}$-based contextuality inequality. These show that contextuality can be used for noise-robust tests of the number of qubits.
Phys. Rev. Lett. 134, 200202 (2025)
Quantum correlations in quantum information, Quantum information processing
One-Dimensional Ising Model with $1/{r}^{1.99}$ Interaction
Conformal field theory | 2025-05-22 06:00 EDT
Dario Benedetti, Edoardo Lauria, Dalimil Mazáč, and Philine van Vliet
We study the 1D Ising model with long-range interactions decaying as $1/{r}^{1+s}$. The critical model corresponds to a family of 1D conformal field theories whose data depend nontrivially on $s$ in the range $1/2\le s\le 1$. The model is known to be described by a generalized free field with quartic interaction, which is weakly coupled near $s=1/2$ but strongly coupled near the short-range crossover at $s=1$. We propose a dual description that becomes weakly coupled at $s=1$. At $s=1$, our model becomes an exactly solvable conformal boundary condition for the 2D free scalar. We perform a number of consistency checks of our proposal and calculate the perturbative conformal field theory data around $s=1$ analytically using both (1) our proposed field theory and (2) the analytic conformal bootstrap. Our results show complete agreement between the two methods.
Phys. Rev. Lett. 134, 201602 (2025)
Conformal field theory, Dualities in field theory, Long-range interactions, Renormalization group, Statistical field theory, 1-dimensional spin chains, Ising model, Quantum field theory (low energy)
Observation of the $W$-Annihilation Process ${D}{s}^{+}\rightarrow \omega {\rho }^{+}$ and Measurement of ${D}{s}^{+}\rightarrow \phi {\rho }^{+}$ in ${D}_{s}^{+}\rightarrow {\pi }^{+}{\pi }^{+}{\pi }^{- }{\pi }^{0}{\pi }^{0}$ Decays
Research article | Branching fraction | 2025-05-22 06:00 EDT
M. Ablikim et al. (BESIII Collaboration)
We present the first amplitude analysis and branching fraction measurement of the decay ${D}{s}^{+}\rightarrow {\pi }^{+}{\pi }^{+}{\pi }^{- }{\pi }^{0}{\pi }^{0}$, using ${e}^{+}{e}^{- }$ collision data collected with the BESIII detector at center-of-mass energies between 4.128 and 4.226 GeV corresponding to an integrated luminosity of $7.33\text{ }\text{ }{\mathrm{fb}}^{- 1}$, and report the first observation of the pure $W$-annihilation decay ${D}{s}^{+}\rightarrow \omega {\rho }^{+}$ with a branching fraction of $(0.99\pm{}0.0{8}{\mathrm{stat}}{ {\text{ }}{- 0.07}^{+0.05}}{\mathrm{syst}})%$. In comparison to the low significance of the $\mathcal{D}$ wave in the decay ${D}{s}^{+}\rightarrow \phi {\rho }^{+}$, the dominance of the $\mathcal{D}$ wave over the $\mathcal{S}$ and $\mathcal{P}$ waves, with a fraction of $(51.85\pm{}7.2{8}{\mathrm{stat}}{ {\text{ }}{- 7.90}^{+4.83}}{\mathrm{syst}})%$ observed in the decay ${D}{s}^{+}\rightarrow \omega {\rho }^{+}$, provides crucial information for the ‘’polarization puzzle,’’ as well as for the understanding of charm meson decays. The branching fraction of ${D}{s}^{+}\rightarrow {\pi }^{+}{\pi }^{+}{\pi }^{- }{\pi }^{0}{\pi }^{0}$ is measured to be $(4.41\pm{}0.1{5}{\mathrm{stat}}\pm{}0.1{3}{\mathrm{syst}})%$. Moreover, the branching fraction of ${D}{s}^{+}\rightarrow \phi {\rho }^{+}$ is measured to be $(3.98\pm{}0.3{3}{\mathrm{stat}}{ {\text{ }}{- 0.19}^{+0.21}}{\mathrm{syst}})%$, and the ${R}{\phi }=\mathcal{B}(\phi \rightarrow {\pi }^{+}{\pi }^{- }{\pi }^{0})/\mathcal{B}(\phi \rightarrow {K}^{+}{K}^{- })$ is determined to be ($0.222\pm{}0.01{9}{\mathrm{stat}}{ {\text{ }}{- 0.016}^{+0.016}}_{\mathrm{syst}}$), which is consistent with the previous measurement based on charm meson decays, but deviates from the results from ${e}^{+}{e}^{- }$ annihilation and $K- N$ scattering experiments by more than $3\sigma $.
Phys. Rev. Lett. 134, 201902 (2025)
Branching fraction, Electroweak interaction, Hadronic decays, Strong interaction, Charm quark, Charmed mesons
First Measurement of Near-Threshold and Subthreshold $J/\psi $ Photoproduction off Nuclei
Research article | Photonuclear reactions | 2025-05-22 06:00 EDT
J. R. Pybus et al.
*et al.*The internal structure of protons bound in nuclei has been probed by studying short-lived particles created when high-energy photons strike nuclei.
Phys. Rev. Lett. 134, 201903 (2025)
Photonuclear reactions
One-Way Valley-Robust Transport in Edge-Tailored Photonic Crystals
Research article | Photonic crystals | 2025-05-22 06:00 EDT
Jianfeng Chen, Yidong Zheng, Shuihua Yang, Fulong Shi, Zhi-Yuan Li, and Cheng-Wei Qiu
Valley photonics, with its rapid advancements and immense potential, lays one pivotal cornerstone toward next-generation topological photonic devices. It enables valley-polarized topological states, whose valleys are intrinsically locked up with transmission directivity. However, these states are prone to defects in photonic structures, and backscattering may easily induce valley flipping. Hence, achieving a one-way valley-robust photonic crystal, immune to perturbations, remains elusive. Here, we demonstrate a one-way, valley-polarized state in an edge-tailored photonic crystal that is robust against defects. Such crystal possesses a Chern band gap and is achieved without using an interface between two crystals with opposite Berry curvatures. We show $K$-valley-robust transport in a defective crystal and demonstrate perfect conversion between the $K$ and ${K}^{‘ }$ valleys in a hybridized crystal while backscattering is greatly suppressed. Our results offer a promising approach for unidirectional control of the valley degrees of freedom in light.
Phys. Rev. Lett. 134, 203803 (2025)
Photonic crystals, Topological materials
Structural Heterogeneity of ${\mathrm{MgSiO}}_{3}$ Liquid and Its Connection with Dynamical Properties
Research article | Earth’s interior | 2025-05-22 06:00 EDT
Shiwei Zhang, Junwei Hu, Xuecheng Sun, Jie Deng, and Haiyang Niu
Silicate melts not only govern key processes in the Earth’s early evolution, but also significantly influence its interior dynamics today. ${\mathrm{MgSiO}}{3}$, a primary component of silicate melts, undergoes significant structural changes and exhibits complex macroscopic properties from the Earth’s surface to the core-mantle boundary. Despite extensive studies, the atomic structure, densification mechanisms, and their connection to dynamics remain unclear. In this Letter, using molecular dynamics simulations with a deep neural network potential, we investigate the atomic structure of ${\mathrm{MgSiO}}{3}$ liquid. Our results reveal significant structural heterogeneity in ${\mathrm{MgSiO}}_{3}$ liquid, with distinct Mg- and Si-enriched regions present throughout the entire mantle pressure range. This heterogeneity offers a new perspective on understanding the densification mechanism, and explains the atomic origin of the viscosity anomaly, as the lifetime of structural heterogeneity aligns well with the Maxwell relaxation time. Our findings provide new insights into the behavior of silicate melts under extreme conditions.
Phys. Rev. Lett. 134, 204101 (2025)
Earth’s interior, High-pressure studies, Structural properties, Multicomponent systems, Supercooled liquid, Viscosity, Machine learning, Molecular dynamics
Intense X-Ray Vortices Generation via Wavefront Shaping in High-Gain Free-Electron Lasers
Research article | Beam dynamics | 2025-05-22 06:00 EDT
Zhikai Zhou, Yin Kang, Weishi Wan, and Chao Feng
The x-ray vortex optical beam, distinguished by its topological charge and orbital angular momentum, offers new insights in probing complex electronic structures, enhancing material characterization, and advancing high-resolution imaging techniques. Here we propose a novel and reliable method to generate intense x-ray vortices with tunable wavelengths in high-gain free-electron lasers (FELs). By simply adjusting the wavefront tilt of the radiation pulse during the FEL gain process, high-quality vortex beam can be amplified until saturation. Compared with existing methods for FEL vortex generation, the proposed technique offers broader wavelength tunability and can be easily implemented in high-gain FEL facilities, regardless of the operating modes.
Phys. Rev. Lett. 134, 205001 (2025)
Beam dynamics, Free-electron lasers
Superconductivity and Charge Density Wave in the Holstein Model on the Penrose Lattice
Research article | Charge density waves | 2025-05-22 06:00 EDT
Lu Liu, Zi-Xiang Li, and Fan Yang
The exotic quantum states emerging in the quasicrystal (QC) have attracted extensive interest because of various properties absent in the crystal. In this Letter, we systematically study the Holstein model at half filling on a prototypical structure of QC, namely rhombic Penrose lattice, aiming at investigating the superconductivity (SC) and other intertwined ordering arising from the interplay between quasiperiodicity and electron-phonon interaction. Through unbiased sign-problem-free determinant quantum Monte Carlo simulations, we reveal the salient features of the ground state phase diagram. Distinct from the results on bipartite periodic lattices at half filling, SC is dominant in a large parameter regime of the electron-phonon coupling (EPC) strength on the Penrose lattice. The strongest SC emerges in the intermediate EPC strength regime, where it coexists with the charge density wave. The charge density wave dominates the SC only in the sufficiently strong EPC regime. Our results also reveal pronounced pairing fluctuation above the transition temperature ${T}{c}$ of the SC. The strong pairing and its fluctuation originate from the cooperative effects of the QC structure without translational symmetry and the macroscopically degenerate confined states at the Fermi energy, which uniquely exist on the Penrose lattice. Our unbiased numerical results suggest that the Penrose lattice is a potential platform to realize strong SC pairing, providing a promising avenue to discover relatively high-${T}{c}$ SC predominantly induced by the EPC.
Phys. Rev. Lett. 134, 206001 (2025)
Charge density waves, Superconductivity, Quasicrystals, Quantum Monte Carlo
Caroli–de Gennes–Matricon Analogs in Full-Shell Hybrid Nanowires
Research article | Andreev bound states | 2025-05-22 06:00 EDT
M. T. Deng, Carlos Payá, Pablo San-Jose, Elsa Prada, C. M. Marcus, and S. Vaitiekėnas
We report tunneling spectroscopy of Andreev subgap states in hybrid nanowires with a thin superconducting full shell surrounding a semiconducting core. The combination of the quantized fluxoid of the shell and the Andreev reflection at the superconductor-semiconductor interface gives rise to analogs of Caroli–de Gennes–Matricon states found in Abrikosov vortices in type-II superconductors. Unlike in metallic superconductors, Caroli–de Gennes–Matricon analogs in full-shell hybrid nanowires manifest as one-dimensional Van Hove singularities with energy spacings comparable to the superconducting gap and independent of the Fermi energy, making them readily observable. Evolution of these analogs with axial magnetic field, skewed within the Little-Parks lobe structure, is consistent with theory and yields information about the radial distribution and angular momenta of the corresponding subbands.
Phys. Rev. Lett. 134, 206302 (2025)
Andreev bound states, Andreev reflection, Bound states, Density of states, Proximity effect, Superconductivity, Vortices in superconductors, Nanowires, Semiconductors
Unconventional Topological Edge States In One-Dimensional Non-Hermitian Gapless Systems Stemming from Nonisolated Hypersurface Singularities
Research article | Edge states | 2025-05-22 06:00 EDT
Hongwei Jia, Jing Hu, Ruo-Yang Zhang, Yixin Xiao, Dongyang Wang, Mudi Wang, Shaojie Ma, Xiaoping Ouyang, Yifei Zhu, and C. T. Chan
Topologically protected edge states have been extensively studied in systems characterized by the topological invariants in band gaps (also called line gaps). In this study, we unveil a whole new form of edge states supported by non-Hermitian systems that transcends the established paradigms of band-gap topology. In contrast to the traditional stable edge states in topological insulators with specific band gaps, the one-dimensional systems we investigate are inherently gapless with the Brillouin zones being mapped to the loops encircling hypersurface singularities in a higher-dimensional space with parity-time symmetry. These hypersurface singularities are nonisolated degeneracies embedded entirely on exceptional surfaces, rendering the energy gaps in our systems inevitably closed at the intersections of the Brillouin zone loop and the exceptional surfaces. Unexpectedly, such gapless systems still afford topologically protected edge states at system boundaries, challenging the conventional understanding based on band gaps. To elucidate the existence of these edge states in the absence of a band-gap-based invariant, we propose a theoretical framework based on eigenframe rotation and deformation that incorporates non-Bloch band theory. Finally, we experimentally demonstrate this new form of topological edge states with nonreciprocal circuits for the first time. Our work extends topological edge states from gapped phases to gapless phases, offering new insights into topological phenomena.
Phys. Rev. Lett. 134, 206603 (2025)
Edge states, Skin effect, Topological materials, 1-dimensional systems, Non-Hermitian systems, Band structure methods
Physical Review X
Hyperdisordered Cell Packing on a Growing Surface
Research article | Growth | 2025-05-22 06:00 EDT
R. J. H. Ross, Giovanni D. Masucci, Chun Yen Lin, Teresa L. Iglesias, Sam Reiter, and Simone Pigolotti
In rapidly growing oval squid, skin pigment cells form a “hyperdisordered” pattern where density fluctuations grow with scale, revealing a novel link between growth and patterning that may apply broadly across biological systems.
Phys. Rev. X 15, 021064 (2025)
Growth, Patterns in complex systems, Scaling laws of complex systems, Packing & jamming problems, Surface growth
Fast and Parallelizable Logical Computation with Homological Product Codes
Research article | Quantum computation | 2025-05-22 06:00 EDT
Qian Xu, Hengyun Zhou, Guo Zheng, Dolev Bluvstein, J. Pablo Bonilla Ataides, Mikhail D. Lukin, and Liang Jiang
New tools for qLDPC error-correction codes enable fast, parallel logical operations with low qubit overhead, enabling efficient, fault-tolerant quantum computing on existing platforms.
Phys. Rev. X 15, 021065 (2025)
Quantum computation, Quantum error correction
arXiv
Two types of $q$-Gaussian distributions used to study the diffusion in a finite region
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-23 20:00 EDT
Won Sang Chung, L. M. Nieto, Soroush Zare, Hassan Hassanabadi
In this work, we explore both the ordinary $ q$ -Gaussian distribution and a new one defined here, determining both their mean and variance, and we use them to construct solutions of the $ q$ -deformed diffusion differential equation. This approach allows us to realize that the standard deviation of the distribution must be a function of time. In one case, we derive a linear Fokker-Planck equation within a finite region, revealing a new form of both the position- and time-dependent diffusion coefficient and the corresponding continuity equation. It is noteworthy that, in both cases, the conventional result is obtained when $ q$ tends to zero. Furthermore, we derive the deformed diffusion-decay equation in a finite region, also determining the position- and time-dependent decay coefficient. A discrete version of this diffusion-decay equation is addressed, in which the discrete times have a uniform interval, while for the discrete positions the interval is not uniform.
Statistical Mechanics (cond-mat.stat-mech)
17 pages, 5 figures
Ambient-pressure superconductivity onset at 10 K and robust Tc under high pressure in TiNbTaN3 medium-entropy nitride
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
Lingyong Zeng, Jie Wang, Hongyu Liu, Longfu Li, Jinjun Qin, Yucheng Li, Rui Chen, Jing Song, Yusheng Hou, Huixia Luo
Superconductivity has been one of the focal points in medium and high-entropy alloys (MEAs-HEAs) since the first discovery of the HEA superconductor in 2014. Until now, most HEAs’ superconducting transition temperature (Tc) has not exceeded 10 K. Here we report the first observation of superconductivity in a bulk medium-entropy nitride (MEN), TiNbTaN3, which shows a Tc of 10 K at ambient pressure. Notably, the electronic specific heat coefficient {\gamma}(H) exhibits nonlinear H-dependence behavior, which is similar to other well-studied multigap superconductors. Furthermore, TiNbTaN3 exhibits extraordinary pressure resilience, maintaining robust superconductivity under high-pressure conditions. Density functional theory (DFT) calculations indicate that pressure exerts a negligible impact on the electronic structures of TiNbTaN3, thereby corroborating the experimental observations. These findings not only advance our understanding of emergent phenomena in entropy-stabilized nitrides but also establish a new material platform for finding more high-Tc superconductors with combinations of 4d/5d transition metal elements and light elements, motivating further investigations into high-entropy functional ceramics for extreme environment applications.
Superconductivity (cond-mat.supr-con)
21 pages, 7 figures. The manuscript with the same title will be published by Advanced Science
Advanced Science 2025
Strong Hilbert space fragmentation and fractons from subsystem and higher-form symmetries
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-23 20:00 EDT
Charles Stahl, Oliver Hart, Alexey Khudorozhkov, Rahul Nandkishore
We introduce a new route to Hilbert space fragmentation in high dimensions leveraging the group-word formalism. We show that taking strongly fragmented models in one dimension and “lifting” to higher dimensions using subsystem symmetries can yield strongly fragmented dynamics in higher dimensions, with subdimensional (e.g., lineonic) excitations. This provides a new route to higher-dimensional strong fragmentation, and also a new route to fractonic behavior. Meanwhile, lifting one-dimensional strongly fragmented models to higher dimensions using higher-form symmetries yields models with topologically robust weak fragmentation. In three or more spatial dimensions, one can also “mix and match” subsystem and higher-form symmetries, leading to canonical fracton models such as X-cube. We speculate that this approach could also yield a new route to non-Abelian fractons. These constructions unify a number of phenomena that have been discussed in the literature, as well as furnishing models with novel properties.
Statistical Mechanics (cond-mat.stat-mech), Strongly Correlated Electrons (cond-mat.str-el), Quantum Physics (quant-ph)
5.5 pages, 2 figures
Gaplessness from disorder and quantum geometry in gapped superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
Omri Lesser, Sagnik Banerjee, Xuepeng Wang, Jaewon Kim, Ehud Altman, Debanjan Chowdhury
It is well known that disorder can induce low-energy Andreev bound states in a sign-changing, but fully gapped, superconductor at $ \pi-$ junctions. Generically, these excitations are localized. Starting from a superconductor with a sign-changing and nodeless order parameter in the clean limit, here we demonstrate a mechanism for increasing the localization length associated with the low-energy Andreev bound states at a fixed disorder strength. We find that the Fubini-Study metric associated with the electronic Bloch wavefunctions controls the localization length and the hybridization between bound states localized at distinct $ \pi-$ junctions. We present results for the inverse participation ratio, superfluid stiffness, site-resolved and disorder-averaged spectral functions as a function of increasing Fubini-Study metric, which indicate an increased tendency towards delocalization. The low-energy properties resemble those of a dirty nodal superconductor with gapless Bogoliubov excitations. We place these results in the context of recent experiments in moire graphene superconductors.
Superconductivity (cond-mat.supr-con), Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
5+7 pages, 3+8 figures
Activation of anomalous Hall effect and orbital magnetization by domain walls in altermagnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-23 20:00 EDT
Altermagnets are an emerging class of unconventional antiferromagnets, characterized by a Néel ordering that does not break the translation symmetry of the underlying lattice. Depending on the orientation of the Néel vector, the anomalous Hall effect (AHE) may or may not exist. In the so-called pure altermagnets, AHE is forbidden by the magnetic symmetry. Here, we demonstrate that in pure altermagnets, the domain walls can lift the symmetry constraints, thereby activating the AHE and orbital magnetization. Taking a representative example of a rutile-lattice tight-binding minimal model in slab geometry, we use the linear response theory to demonstrate the emergence of the domain wall AHE, finding that it is closely related with the orbital magnetization, while the spin magnetization does not play a significant role. Using Landau theory, we argue that while for a random arrangement of $ \pi$ domain walls, the contributions from the individual domain walls will cancel one another, an external magnetic field will favor domain-wall arrangements with specific chirality giving rise to a net AHE signal. Using group theory, we discuss how these findings can be generalized straightforwardly to certain other classes of altermagnets. Our work reveals a crucial role of the domain walls in the understanding of the Hall transport and orbital magnetism of altermagnets.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
14 pages, 13 figures
Pairing mechanism and superconductivity in pressurized La$_5$Ni$3$O${11}$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
Ming Zhang, Cui-Qun Chen, Dao-Xin Yao, Fan Yang
The discovery of superconductivity (SC) with critical temperature $ T_c$ above the boiling point of liquid nitrogen in pressurized La$ _3$ Ni$ _2$ O$ _{7}$ has sparked a surge of exploration of high-$ T_c$ superconductors in the Ruddlesden-Popper (RP) phase nickelates. More recently, the RP phase nicklate La$ _5$ Ni$ _3$ O$ _{11}$ , which hosts layered structure with alternating bilayer and single-layer NiO$ _2$ planes, is reported to accommodate SC under pressure, exhibiting a dome-shaped pressure dependence with highest $ T_c\approx 64$ K, capturing a lot of interests. Here, using density functional theory (DFT) and random phase approximation (RPA) calculations, we systematically study the electronic properties and superconducting mechanism of this material. Our DFT calculations yield a band structure including two nearly decoupled sets of sub-band structures, with one set originating from the bilayer subsystem and the other from the single-layer one. RPA-based analysis demonstrates that SC in this material occurs primarily within the bilayer subsystem exhibiting an $ s^\pm$ wave pairing symmetry similar to that observed in pressurized La$ _3$ Ni$ _2$ O$ _{7}$ , while the single-layer subsystem mainly serves as a bridge facilitating the inter-bilayer phase coherence through the interlayer Josephson coupling (IJC). Since the IJC thus attained is extremely weak, it experiences a prominent enhancement under pressure, leading to the increase of the bulk $ T_c$ with pressure initially. When the pressure is high enough, the $ T_c$ gradually decreases due to the reduced density of states on the $ \gamma$ -pocket. In this way, the dome-shaped pressure dependence of $ T_c$ observed experimentally is naturally understood.
Superconductivity (cond-mat.supr-con)
11 pages, 6 figures
Phonon, Infrared and Raman Spectra of LiGa5O8 from Density Functional Perturbation Theory
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Sarker Md. Sadman, Walter R. L. Lambrecht
LiGa$ _5$ O$ _8$ with a cubic spinel type structure was recently reported to be a ultra-wide-band-gap semiconductor with unintentional p-type conduction. While the origin of p-type doping is still unclear, the fundamental properties of this material are of interest. Here we present a first-principles study of the phonons using density functional perturbation theory. The phonon band structures show no unstable modes verifying the stability of the structure. We focus mainly on the phonons at the Brillouin zone center for which a full symmetry analysis is presented. We present the dielectric function contributions from the infrared active modes as well as the Raman spectra and their polarization dependence. The phonon density of states integrated over the Brillouin zone is also presented as this may related to disordered Raman spectra.
Materials Science (cond-mat.mtrl-sci)
Self-heating electrochemical memory for high-precision analog computing
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Adam L. Gross, Sangheon Oh, François Léonard, Wyatt Hodges, T. Patrick Xiao, Joshua D. Sugar, Jacklyn Zhu, Sritharini Radhakrishnan, Sangyong Lee, Jolie Wang, Adam Christensen, Sam Lilak, Patrick S. Finnegan, Patrick Crandall, Christopher H. Bennett, William Wahby, Robin Jacobs-Gedrim, Matthew J. Marinella, Suhas Kumar, Sapan Agarwal, Yiyang Li, A. Alec Talin, Elliot J. Fuller
Artificial intelligence (AI) is pushing the limits of digital computing to such an extent that, if current trends were to continue, global energy consumption from computation alone would eclipse all other forms of energy within the next two decades. One promising approach to reduce energy consumption and to increase computational speed is in-memory analog computing. However, analog computing necessitates a fundamental rethinking of computation at the material level, where information is stored as continuously variable physical observables. This shift introduces challenges related to the precision, dynamic range, and reliability of analog devices - issues that have hindered the development of existing memory technology for use in analog computers. Here, we address these issues in the context of memory which stores information as resistance. Our approach utilizes an electrochemical cell to tune the bulk oxygen-vacancy concentration within a metal oxide film. Through leveraging the gate contact as both a heater and source of electrochemical currents, kinetic barriers are overcome to enable a dynamic range of nine decades of analog tunable resistance, more than 3,000 available states, and programming with voltages less than 2 V. Furthermore, we demonstrate deterministic write operations with high precision, current-voltage linearity across six decades, and programming speeds as fast as 15 ns. These characteristics pave the way toward low-power analog computers with potential to improve AI efficiency by orders of magnitude.
Materials Science (cond-mat.mtrl-sci)
Generalized Rosenfeld-Tarazona scaling and high-density specific heat of simple liquids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-23 20:00 EDT
The original Rosenfeld-Tarazona (RT) scaling of the excess energy in simple dense fluids predicts a $ \propto T^{3/5}$ thermal correction to the fluid Madelung energy. This implies that the excess isochoric heat capacity scales as $ C_{\rm v}^{\rm ex}\propto T^{-2/5}$ . Careful examination performed in this paper demonstrates that the exponent $ -2/5$ is not always optimal. For instance, in the Lennard-Jones fluid in some vicinity of the triple point, the exponent $ -1/3$ turns out to be more appropriate. The analysis of the specific heat data in neon, argon, krypton, xenon, and liquid mercury reveals that no single value of the exponent exists, describing all the data simultaneously. Therefore we propose a generalized RT scaling in the form $ C_{\rm v}^{\rm ex}\propto T^{-\alpha}$ , where $ \alpha$ is a density- and material-dependent adjustable parameter. The question concerning which material properties and parameters affect the exponent $ \alpha$ and whether it can be predicted from general physical arguments requires further investigation.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Chemical Physics (physics.chem-ph)
Phys. Fluids 36, 117119 (2024)
Interpretation of run-and-tumble motion as jump-process: the case of a harmonic trap
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-23 20:00 EDT
By mapping run-and-tumble motion onto jump-process (a process in which a particle, instead of moving continuously in time, performs consequential jumps), a system in a steady-state can be formulated as an integral equation. The key ingredient of this formulation is the transition operator $ G(x,x’)$ , representing the probability distribution of jumps along the $ x$ -axis for a particle located at $ x’$ before a jump. For particles in a harmonic trap, exact expressions for $ G(x,x’)$ are obtained and, in principle, $ G(x,x’)$ has all the information about a stationary distribution $ \rho(x)$ . One way to extract $ \rho$ is to use the condition of stationarity, $ \rho(x) = \int dx’ , \rho(x’) G(x,x’)$ , resulting in an integral equation formulation of the problem. For the system in dimension $ d=2$ , there is an unexpected reduction of complexity; the expression for $ G(x,x’)$ is found to be reversible, which implies that $ \rho(x)$ (within the jump-process interpretation) obeys the detailed balance condition, and $ \rho$ can be obtained from the detailed balance relation, $ \rho(x’) G(x,x’) = \rho(x) G(x’,x)$ .
Statistical Mechanics (cond-mat.stat-mech)
Electronic mobility, doping, and defects in epitaxial $\mathrm{BaZrS_3}$ chalcogenide perovskite thin films
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Jack Van Sambeek, Jessica Dong, Anton V. Ievlev, Tao Cai, Ida Sadeghi, Rafael Jaramillo
We present the electronic transport properties of $ \mathrm{BaZrS_3}$ (BZS) thin films grown epitaxially by gas-source molecular beam epitaxy (MBE). We observe n-type behavior in all samples, with carrier concentration ranging from $ 4 \times 10^{18}$ to $ 4 \times 10^{20} \mathrm{cm^{-3}}$ at room temperature (RT). We observe a champion RT Hall mobility of 11.1 $ \mathrm{cm^2V^{-1}s^{-1}}$ , which is competitive with established thin-film photovoltaic (PV) absorbers. Temperature-dependent Hall mobility data show that phonon scattering dominates at room temperature, in agreement with computational predictions. X-ray diffraction data illustrate a correlation between mobility and stacking fault concentration, illustrating how microstructure can affect transport. Despite the well-established environmental stability of chalcogenide perovskites, we observe significant changes to electronic properties as a function of storage time in ambient conditions. With the help of secondary-ion mass-spectrometry (SIMS) measurements, we propose and support a defect mechanism that explains this behavior: as-grown films have a high concentration of sulfur vacancies that are shallow donors ($ \mathrm{V_S^\bullet}$ or $ \mathrm{V_S^{\bullet \bullet}}$ ), which are converted into neutral oxygen defects ($ \mathrm{O_S^\times}$ ) upon air exposure. We discuss the relevance of this defect mechanism within the larger context of chalcogenide perovskite research, and we identify means to stabilize the electronic properties.
Materials Science (cond-mat.mtrl-sci)
Holstein mechanism in single-site model with unitary evolution
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-23 20:00 EDT
We consider the Holstein mechanism in single electron (one-site) system with unitary evolution that is intrinsic to both the fermion and boson operators in the case of nonadiabatic limit. The unitary dynamics as well as boson-frequency-dependence provide the evidence of quantum phase transition from the distinct behaviors at short-time and long-time stages, which exhibit power law and exponential law decay, respectively, as can be seem from the polaronic shift.
Disordered Systems and Neural Networks (cond-mat.dis-nn)
Distribution of antiferromagnetic rare-earth domains in multiferroic Dy${0.7}$Tb${0.3}$FeO$_3$
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Yannik Zemp, Ehsan Hassanpour, Jan Gerrit Horstmann, Yusuke Tokunaga, Yasujiro Taguchi, Yoshinori Tokura, Thomas Lottermoser, Mads C. Weber, Manfred Fiebig
In many multiferroics, rare-earth and transition-metal orders exist side by side. For analyzing their interaction and its consequences for the multiferroic state, the associated domain patterns and their spatial correlation can give valuable insight. Unfortunately, this is often hampered by the lack of access to the domains of the rare-earth order. Here, we uncover such a domain pattern for the antiferromagnetic and multiferroic Dy$ _{0.7}$ Tb$ _{0.3}$ FeO$ _3$ . Optical second harmonic generation reveals the formation of column-like Dy/Tb domains. Interestingly, the columns form perpendicular to the magnetically induced electric polarization. Hence, the antiferromagnetic rare-earth order forces the ferroelectric domains to form nominally charged head-to-head and tail-to-tail domain walls, thus playing a leading role in the domain formation within the multiferroic phase. In turn, to reduce energy cost, the ferroelectric order causes a reduced rare-earth domain-wall density along the direction of the electric polarization. This interplay highlights the multiferroic character of the Dy$ _{0.7}$ Tb$ _{0.3}$ FeO$ _3$ domain pattern. We position Dy$ _{0.7}$ Tb$ _{0.3}$ FeO$ _3$ within the broader landscape of rare-earth multiferroics and identify three distinct scenarios for the role of rare-earth order in these.
Materials Science (cond-mat.mtrl-sci)
14 pages, 6 figures
Inchworm Tensor Train Hybridization Expansion Quantum Impurity Solver
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-23 20:00 EDT
Yang Yu, André Erpenbeck, Dominika Zgid, Guy Cohen, Olivier Parcollet, Emanuel Gull
The investigation of quantum impurity models plays a crucial role in condensed matter physics because of their wide-ranging applications, such as embedding theories and transport problems. Traditional methods often fall short of producing accurate results for multi-orbital systems with complex interactions and off-diagonal hybridizations. Recently, tensor-train-based integration and summation techniques have shown promise as effective alternatives. In this study, we use tensor train methods to tackle quantum impurity problems formulated within the imaginary-time inchworm hybridization expansion framework. We identify key challenges in the inchworm expansion itself and its interplay with tensor-train-based methods. We demonstrate the accuracy and versatility of our approach by solving general quantum impurity problems. Our results suggest that tensor-train decomposition schemes offer a viable path toward accurate and efficient multi-orbital impurity solvers.
Strongly Correlated Electrons (cond-mat.str-el)
19 pages, 9 figures
Geometric Frustration in Twist-Bend Nematic Droplets
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-23 20:00 EDT
Joseph Pollard, Richard G. Morris
Liquid crystals formed of bent-core molecules are exotic materials that exhibit the twist-bend nematic phase. This arises when an energetic preference for nonzero local bend distortion is accommodated via twist in the texture, resulting in properties synonymous with both smectics and cholesterics. Here we describe how the frustration inherent to the twist-bend phase can be exacerbated by confinement and boundary anchoring. Using a combination of numerical simulations, topological and geometric analysis, we catalogue the equilibrium textures that arise in spherical twist-bend droplets with a radial anchoring as the two key parameters – the molecular cone angle and the ratio between the pitch length and droplet radius – are varied. This form of confinement is known to produce a wide variety of topologically and geometrically complex metastable states in cholesterics. We find that twist-bend nematic droplets are no different, exhibiting a variety of complex layered states, defect constellations, and Hopfions. However, whilst many of the structures and defect configurations that we observe are equivalent to their cholesteric counterparts, they are geometrically very distinct, in part due to the absence of chirality.
Soft Condensed Matter (cond-mat.soft)
20 pages, 10 figures
Exact Expansion Formalism for Transport Properties of Heterogeneous Materials Characterized by Arbitrary Continuous Random Fields
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Liyu Zhong, Yang Jiao, Sheng Mao
We derive an exact contrast-expansion formalism for the effective conductivity of heterogeneous materials (media) with local properties described by arbitrary continuous random fields, significantly generalizing the widely used binary-field models. The theory produces a rapidly convergent Neumann-series that, upon Gaussian closure via a Hermite expansion, yields closed-form first-, second- and third-order approximations, which achieve percent-level accuracy at first order for isotropic media. For anisotropic media, second-order approximations achieve sub-2% accuracy across a wide range of local property contrasts and correlations. Our formalism provides mathematically rigorous structure-property closures, with significant implications for the discovery and design of novel graded and architected materials with tailored transport properties.
Materials Science (cond-mat.mtrl-sci)
4 pages, 3 figures
Ultrafast charge-transfer dynamics in Ca$_2$CuO$_2$Cl$_2$ from time-resolved optical reflectivity
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-23 20:00 EDT
Haiyun Huang, Xiu Zhang, Junzhi Zhu, Jianfa Zhao, Lin Zhao, Yu-Xia Duan, Jian-Qiao Meng, X. J. Zhou, Changqing Jin, Haiyun Liu
We employ time-resolved optical reflectivity to investigate the ultrafast dynamics of the charge-transfer gap (CTG) in a parent cuprate compound Ca$ _2$ CuO$ _2$ Cl$ _2$ (CCOC). We observe a persistent photoinduced red shift of the CTG that lasts up to 1000 ps. The red shift during the slow decay after 10 ps can be well modeled by the localized picture, whereas its maximum value at ~0.9 ps involves additional contribution from the renormalization of the Hubbard U due to screening effect from delocalized electrons. Furthermore, coupling between the mid-gap absorption and a slow acoustic phonon launches coherent oscillations below the CTG, observed as a ~20 GHz modulation with a dispersion independent of the pump fluence. These results demonstrate the tunning of the CTG by light, unveil complex interplay between multiple degrees of freedom, and contribute to a deeper understanding of superconductivity and correlated materials.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
Phys. Rev. Research 7, 023175 (2025)
Pure nematic transition inside the superconducting dome of iron chalcogenide superconductor FeSe$_{1-x}$Te$_x$
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
K. Y. Liang, R .Z. Zhang, Z. F. Lin, Z. J. Li, B. R. Chen, P. H. Zhang, K. Z. Yao, Q. S. He, Q. Z. Zhou, H. X. Yao, K. Jin, Y. H. Wang
Nematicity and magnetism are prevalent orders in high transition temperature (Tc) superconductors, coexisting in the parent compound of most material families. Quantum fluctuations of nematicity or spin orders are both plausible candidates for mediating unconventional Cooper pairing. Identifying the sole effect of a nematic quantum critical point (QCP) on the emergence of superconducting dome without interference of spin fluctuations is therefore highly desirable. The iron chalcogenide superconductor FeSe exhibits pure nematicity without any magnetic ordering. A nematic quantum phase transition can be induced by Te substitution but experimental study of such transition is so far limited to its normal state. By performing local susceptometry on composition-spread FeSe$ _{1-x}$ Te$ _x$ films ($ 0 < x < 1$ ) using scanning Superconducting Quantum Interference Device (sSQUID) microscopy, we investigate the superfluid density ($ \rho_s$ ) across the pure nematic transition in extremely fine steps of $ {\Delta}x$ = 0.0008. The temperature dependence of $ \rho_s$ changes from the form of anisotropic pairing on the nematic side to an isotropic one across the critical doping $ x_c$ . The power-law dependence of gap anisotropy on $ |x - x_c|$ provides evidence for nematic quantum criticality under the superconducting dome. The low-temperature $ \rho_s$ scales linearly with Tc in the nematic phase $ x < x_c$ , whereas the gap amplitude, maximized at $ x_c$ , determines the Tc for $ x>x_c$ . Our results establish a pure nematic QCP in FeSe$ _{1-x}$ Te$ _x$ , separating two superconducting orders with distinct pairing boosted by nematic quantum fluctuations.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Pressure evolution of coplanar antiferromagnetism in heavy-fermion Ce${2}$CoAl${7}$Ge$_{4}$
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-23 20:00 EDT
M. O. Ajeesh, A. O. Scheie, Yu Liu, L. Keller, S. M. Thomas, P. F. S. Rosa, E. D. Bauer
Ce$ _{2}$ M$ Al$ _{7}$ Ge$ _{4}$ ($ M=$ Co, Ir, Ni or Pd) are heavy-fermion materials and host a variety of ground states ranging from magnetism to non-Fermi liquid behavior. The Co, Ir, and Ni members of the series undergo magnetic ordering with decreasing transition temperatures. In contrast, the Pd compound does not magnetically order down to 0.4 K and shows non-Fermi liquid behavior, suggesting proximity to a magnetic quantum critical point. Among the series, Ce$ _{2}$ CoAl$ _{7}$ Ge$ _{4}$ orders antiferromagnetically below $ T_N=1.9$ K along with heavy-fermion behavior below 15 K. We report the magnetic structure of the antiferromagnetic phase in Ce$ _{2}$ CoAl$ _{7}$ Ge$ _{4}$ and the evolution of the magnetic transition under external pressure. Rietveld refinement of the neutron diffraction data suggests a coplanar antiferromagnetic structure with a wave vector $ k = (1,1,1)$ and an ordered moment of $ 0.383 \pm 0.018 > \mu_B$ in the antiferromagnetic phase. Electrical resistivity and AC calorimetry measurements under hydrostatic pressure reveal a suppression of the antiferromagnetic transition toward zero temperature around $ p=1.1$ GPa. However, there is no evidence of non-Fermi liquid behavior associated with the suppression of magnetism by pressure, unlike the effect of transition-metal substitution.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 7 figures
Finite temperatures and flat bands: the Hubbard model on three-dimensional Lieb lattices
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-23 20:00 EDT
Lucas O. Lima, Julián Faúndez, Natanael C. Costa, Raimundo R. dos Santos
We investigate some thermodynamic and magnetic properties of the Hubbard model on two three-dimensional extensions of the Lieb lattice: the perovskite Lieb lattice (PLL) and the layered Lieb lattice (LLL). Using determinant quantum Monte Carlo (DQMC) simulations alongside Hartree-Fock and cluster mean-field theory (CMFT) approaches, we analyze how flat-band degeneracy, connectivity, and lattice anisotropy influence the emergence of magnetic order. Our results show that both geometries support finite-temperature magnetic transitions, namely ferromagnetic (FM) on the PLL, and antiferromagnetic (AFM) on the LLL. Further, we have established that the critical temperature, $ T_c$ , as a function of the uniform on-site coupling, $ U$ , displays a maximum, which is smaller in the AFM case than in the FM one, despite the absence of flat bands in the LLL. We also provide numerical evidence to show that flat bands in the PLL rapidly generate magnetic moments, but a small interorbital coordination suppresses the increase of $ T_c$ at large interaction strength $ U/t$ . By contrast, the LLL benefits from higher connectivity, favoring magnetic order even in the absence of flat bands. The possibilities of anisotropic interlayer hoppings and inhomogeneous on-site interactions were separateley explored. We have found that magnetism in the PLL is hardly affected by hopping anisotropy, since the main driving mechanism is the preserved flat band; for the LLL, by contrast, spectral weight is removed from $ d$ -sites, which increases $ T_c$ more significantly. At mean-field level, we have obtained that setting $ U=0$ on $ p$ sites and $ U=U_d\neq0$ on $ d$ sites leads to a quantum critical point at some $ U_d$ ; this behavior was not confirmed by our DQMC simulations.
Strongly Correlated Electrons (cond-mat.str-el)
12 pages, 12 figures
Magnetic Charge State Controlled Spin-Wave Dynamics in Nanoscale Three-Dimensional Artificial Spin Ice
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-23 20:00 EDT
Chandan Kumar, Amrit Kumar Mondal, Sreya Pal, Sayan Mathur, Jay R. Scott, Arjen van Den Berg, Adekunle O. Adeyeye, Sam Ladak, Anjan Barman
Three-dimensional (3D) magnetic nanostructures offer a versatile platform for exploring complex spin textures and spin-wave (SW) dynamics, with implications in next-generation spintronic and magnonic technologies. Advances in 3D nanofabrication have allowed a wide-range of structures and phenomena to be realized. Whilst the study of simple cylindrical magnetic nanowires allows the realization of ultrafast domain walls and a spin Cherenkov effect, placing such wires of complex cross-section into 3D arrangements allows one to produce magnetic metamaterials, known as artificial spin-ice (ASI), where the overall ground state and spin dynamics are governed by magnetostatic interactions between elements. Here, using Brillouin Light Scattering (BLS) we demonstrate the direct detection of magnetic charged states in a 3D-ASI system. The measured spin-wave modes in 3D-ASI are found to be directly controlled by the local magnetic charge configuration and the direction of the applied magnetic field. Micromagnetic simulations provide insight into the spatially selective excitation of spin waves and the evolution of magnetic microstates, uncovering a direct link to the field-dependent characteristics of the spin-wave spectrum. These findings make 3D-ASI architectures a promising system to realize reconfigurable, low-power magnonic devices with engineered collective dynamics.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
Statistical properties of non-linear observables of fractal Gaussian fields with a focus on spatial-averaging observables and on composite operators
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-23 20:00 EDT
The statistical properties of non-linear observables of the fractal Gaussian field $ \phi(\vec x)$ of negative Hurst exponent $ H<0$ in dimension $ d$ are revisited with a focus on spatial-averaging observables and on the properties of the finite parts $ \phi_n(\vec x)$ of the ill-defined composite operators $ \phi^n(\vec x) $ . For the special case $ n=2$ of quadratic observables, explicit results include the cumulants of arbitrary order, the Lévy-Khintchine formula for the characteristic function and the anomalous large deviations properties. The case of observables of arbitrary order $ n>2$ is analyzed via the Wiener-Ito chaos-expansion for functionals of the white noise: the multiple stochastic Ito integrals are useful to identify the finite parts $ \phi_n(\vec x)$ of the ill-defined composite operators $ \phi^n(\vec x) $ and to compute their correlations involving the Hurst exponents $ H_n=nH$ .
Statistical Mechanics (cond-mat.stat-mech), Probability (math.PR)
35 pages
Diffraction Stress Factors Calculated Using a Maximum Entropy Method
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Maximilian Krause, Nicola Simon, Claudius Klein, Jens Gibmeier, Thomas Böhlke
Diffraction-based stress analysis of textured materials depends on understanding their elastic heterogeneity and its influence on microscopic strain distributions, which is generally done by using simplifying assumptions for crystallite interactions to calculate tensorial stress factors or in the case of very strong textures, by considering the material phase as a single crystal (crystallite group method). In this paper, we apply the micromechanical Maximum Entropy Method (MEM) to this purpose, which marks its first use for materials with texture. The special feature of this approach is a native parametrization by the effective stiffness of the material, which allows the approach to be tailored to a macroscopically measurable sample property. We perform example stress analyses of cold-rolled copper, finding through validation with full-field simulations that the MEM yields accurate local strains even for materials with extremely sharp textures. In an example stress analysis of mildly textured cold-rolled ferritic steel, the accuracy of the approach compares favorably to the established Voigt, Reuss and self-consistent Eshelby-Kröner approaches. Compared to the latter, the method is also numerically efficient to calculate.
Materials Science (cond-mat.mtrl-sci)
41 pages, 10 figures
Materials Generation in the Era of Artificial Intelligence: A Comprehensive Survey
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Zhixun Li, Bin Cao, Rui Jiao, Liang Wang, Ding Wang, Yang Liu, Dingshuo Chen, Jia Li, Qiang Liu, Yu Rong, Liang Wang, Tong-yi Zhang, Jeffrey Xu Yu
Materials are the foundation of modern society, underpinning advancements in energy, electronics, healthcare, transportation, and infrastructure. The ability to discover and design new materials with tailored properties is critical to solving some of the most pressing global challenges. In recent years, the growing availability of high-quality materials data combined with rapid advances in Artificial Intelligence (AI) has opened new opportunities for accelerating materials discovery. Data-driven generative models provide a powerful tool for materials design by directly create novel materials that satisfy predefined property requirements. Despite the proliferation of related work, there remains a notable lack of up-to-date and systematic surveys in this area. To fill this gap, this paper provides a comprehensive overview of recent progress in AI-driven materials generation. We first organize various types of materials and illustrate multiple representations of crystalline materials. We then provide a detailed summary and taxonomy of current AI-driven materials generation approaches. Furthermore, we discuss the common evaluation metrics and summarize open-source codes and benchmark datasets. Finally, we conclude with potential future directions and challenges in this fast-growing field. The related sources can be found at this https URL.
Materials Science (cond-mat.mtrl-sci), Artificial Intelligence (cs.AI)
Work in progress
Electronic and Vibrational Properties of Layered Boron Nitride Polymorphs
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Priyanka Mishra, Nevill Gonzalez Szwacki
We present a comprehensive first-principles investigation of the structural, electronic, and vibrational properties of four layered boron nitride (BN) polymorphs–AA-stacked ($ e$ -BN), AA$ ^\prime$ -stacked ($ h$ -BN), ABC-stacked ($ r$ -BN), and AB-stacked ($ b$ -BN). Using density functional theory and density functional perturbation theory with and without van der Waals (vdW) corrections, we quantify the impact of interlayer dispersion on lattice parameters, electronic band gaps, phonon frequencies, and infrared and Raman intensities. Our results demonstrate that vdW interactions are essential for reproducing experimental lattice constants and stabilizing interlayer phonon modes. The vibrational spectra exhibit distinct stacking-dependent features, enabling clear differentiation among polytypes. Notably, $ b$ -BN displays a direct band gap, while $ r$ -BN shows enhanced IR and Raman activity due to LO-TO splitting and symmetry breaking. These findings underscore the critical role of interlayer interactions in determining the physical properties of $ sp^2$ -bonded BN and offer insight into the experimental identification and functionalization of BN polytypes for electronic and photonic applications.
Materials Science (cond-mat.mtrl-sci)
8 pages, 4 figures, 4 tables
High-pressure high-temperature solution growth, structural, and superconducting properties of Fe-substituted MgB2 single crystals
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
Clarifying the impact of Fe doping on the structural and superconducting properties of MgB2 is crucial, considering that iron is commonly used as a sheath material for the fabrication of metal-clad MgB2 wires and tapes. To date the effects of Fe doping have only been investigated in polycrystalline samples, but the obtained results are controversial. Here, we report the successful growth of Mg1-xFexB2 single crystals in a quaternary Mg-Fe-B-N system using the cubic anvil high-pressure and high-temperature technique. The reaction took place in a closed boron nitride crucible at a pressure of 3 GPa and a temperature of 1960 °C. The grown crystals exhibit plate-like shapes with sizes up to 0.9 x 0.7 x 0.1 mm3. The variation of the critical temperature Tc of Mg1-xFexB2 crystals with Fe content was found to be different from that observed in polycrystalline samples. For a small Fe doping, up to x < 0.03, the behaviour of Tc(x) is similar to that for the crystals with Al and C substitutions, which suggests that Fe is in non-magnetic state. In this doping range, measurements of the temperature-dependent magnetization performed in high magnetic fields exclude spin states other than S = 0 for the Fe ions. However, for x > 0.03, certain crystals start to show a dramatic decrease in Tc, suggesting that Fe might be in a magnetic state. The M-H dependence for these crystals shows significant increase of magnetization with increasing field in low magnetic field, pointing to a weak ferromagnetism. Overall, the availability of Fe substituted MgB2 single crystals exhibiting such peculiar behaviour offers a unique opportunity to investigate the effect of disorder alone on one hand and the influence of magnetic substituent on the superconducting characteristics on the other.
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci)
J. Cryst. Growth 667 (2025) 128244
The Solution of the Critical Dynamics of the Mean-Field Kob-Andersen Model
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-23 20:00 EDT
Gianmarco Perrupato, Tommaso Rizzo
We analytically solve the critical dynamics of the Kob-Andersen kinetically constrained model of supercooled liquids on the Bethe lattice, employing a combinatorial argument based on the cavity method. For arbitrary values of graph connectivity z and facilitation parameter m, we demonstrate that the critical behavior of the order parameter is governed by equations of motion equivalent to those found in Mode-Coupling Theory. The resulting predictions for the dynamical exponents are validated through direct comparisons with numerical simulations that include both continuous and discontinuous transition scenarios.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
11 pages, 7 figures
Clogging-unclogging transition in 2D vertical pipe
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-23 20:00 EDT
Y. Zhou, M. Li, Y. Wang, Y. Guan, Y. Liu, Z. Zou
We experimentally and numerically investigate the clogging behavior of granular materials in a two-dimensional vertical pipe. The nonmonotonicity of clogging probability found in cylindrical vertical pipe is also observed in the two-dimensional case. We numerically demonstrate that the clogging probability strongly correlates with the friction coefficient $ \mu$ , in addition to the pipe-to-particle diameter ratio $ D/d$ . We thus construct a clogging-unclogging $ D/d$ -$ \mu$ phase diagram within the $ 2<D/d<3$ range. Finally, by analyzing the geometrical arrangements of particles and using a simple analysis of forces and torques, we are able to predict the clogging-unclogging transition in the $ D/d$ -$ \mu$ phase diagram and explain the mechanism of the observed counterintuitive nonmonotonicity in more detail. From this work, we identify two primary conditions for clogging formation: first, all particles must achieve force and torque equilibrium; second, they must geometrically form an arch. Our theoretical analysis reveals that the clogging-unclogging transition in vertical pipe is a natural example of the shear jamming transition.
Soft Condensed Matter (cond-mat.soft)
submitted to Physical Review Letters
Role of Translational Noise in Motility-Induced Phase Separation of Hard Active Particles
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-23 20:00 EDT
Felipe Hawthorne, Pablo de Castro, José A. Freire
Self-propelled particles, like motile cells and artificial colloids, can spontaneously form macroscopic clusters. This phenomenon is called motility-induced phase separation (MIPS) and occurs even without attractive forces, provided that the self-propulsion direction fluctuates slowly. In addition to rotational noise, these particles may experience translational noise, not coupled to rotational noise, due to environmental fluctuations. We study the role of translational noise in the clustering of active Brownian hard disks. To tease apart the contribution of translational noise, we model excluded-volume interactions through a Monte-Carlo-like overlap rejection approach. Upon increasing the translational diffusivity, we find that clusters become more rounded (less fractal), eventually transitioning to genuine MIPS. For sufficiently higher translational diffusivity, clusters melt down. We develop a theory for the cluster mass distribution, and employ a hydrodynamic approach with parameters taken from the simulation, that explains the clustering phase diagram.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
Kinetically controlling surface atom arrangements in thermally robust, amorphous high-entropy alloy nanoparticles by solvent selection
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Varatharaja Nallathambi, Se-Ho Kim, Baptiste Gault, Sven Reichenberger, Dierk Raabe, Stephan Barcikowski
The ability to tailor nanoscale surface atom arrangements through multi-elemental compositional control provides high-entropy nanoalloys with promising functional properties. Developing a fundamental understanding of nanoalloy formation mechanisms during synthesis is therefore essential for effectively engineering the surface composition and resulting functional properties. Using the Cantor alloy (CrMnFeCoNi) as a model system, we investigate how solvent selection during reactive, nanosecond-pulsed laser synthesis influences carbon doping and the resulting changes in nanoparticle morphology, structure, and composition. Supersaturated carbon incorporation, partitioned from the organic solvent molecules, produces amorphous nanoparticles with distinctive carbon shells, thermally stable up to 350 °C. We propose kinetically controlled particle formation mechanisms and rationalize the criticality of the time scales between the competing reactions of carbon doping, carbon shell formation, and coalescence of metallic fragments, ruling compositional and morphological characteristics. This work demonstrates effective solvent-driven surface-compositional control in amorphous high-entropy nanoalloys. It introduces a novel synthesis approach for tailoring surface atom arrangements through carbon incorporation via reactive, pulsed laser synthesis.
Materials Science (cond-mat.mtrl-sci)
Phonon-limited carrier transport in the Weyl semimetal TaAs
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Zhe Liu, Shashi B. Mishra, Jae-Mo Lihm, Samuel Poncé, Elena R. Margine
Topological Weyl semimetals represent a novel class of quantum materials that exhibit remarkable properties arising from their unique electronic structure. In this work, we employ state-of-the-art ab initio methods to investigate the role of the electron-phonon interactions on the charge transport properties of TaAs. Our calculations of the temperature-dependent electrical conductivity with the iterative Boltzmann transport equation show excellent agreement with experimental measurements above 100 K. Extending the analysis to doped systems, we demonstrate that even small shifts in the Fermi level can lead to substantial changes in conductivity, driven by the complex topology of the Fermi surface. In particular, modifications in Fermi surface nesting emerge as a key factor influencing scattering processes and carrier lifetimes. These findings offer critical insights into the microscopic mechanisms that govern transport in TaAs and highlight the sensitivity of Weyl semimetals to doping and carrier dynamics.
Materials Science (cond-mat.mtrl-sci)
Comment on “Shell-Shaped Quantum Droplet in a Three-Component Ultracold Bose Gas”
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-23 20:00 EDT
In a recent paper (Y. Ma and X. Cui, Phys. Rev. Lett. 134, 043402 (2025)), a new type of shell-shaped Bose-Einstein condensate with a self-bound character has been proposed, made of three-component $ Na^{23}K^{39}K^{41}$ Bose mixture (species (1,2,3) in the following), where the mixtures (1, 2) and (2, 3) both form quantum droplets. The proposed structures are made of an outer shell of liquid (1,2) enveloping a spherical core of (2,3) liquid, which is claimed to be stable without the need of any trapping potential. I comment in the following that these structures are not actually the ground-states solutions to the system but rather local energy minima, and most likely impossible to realize in practice.
Quantum Gases (cond-mat.quant-gas)
Comment on arXiv:2312.15846
Orbital-resolved anisotropic electron pockets in electron-doped SrTiO3 observed by ARPES
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Yuki K. Wakabayashi, Akihira Munakata, Yoshitaka Taniyasu, Masaki Kobayashi
SrTiO3 has attracted considerable interest as a wide-band gap semiconductor for advanced high-k capacitors and photocatalytic applications. Although previous angle-resolved photoemission spectroscopy (ARPES) studies have characterized the valence band structure originating from O 2p orbitals, the conduction band arising from Ti 3d orbitals upon electron doping, which is called electron pockets, remain poorly understood. In this study, polarization-dependent ARPES measurements were performed on Nb 1%-doped SrTiO3 (001), enabling direct, orbital-selective visualization of the electron pockets. From the measured band dispersion, we quantitatively determined their effective masses, anisotropy, and electron density. Our results revealed formation of an electron pocket at the Gamma point induced by Nb doping, yielding a direct bandgap of 3.79 eV at Gamma, consistent with previous optical measurements. Furthermore, the effective masses of m1 = 0.63m0 (short-axis direction) and m2 = 8.0m0 (long-axis direction) were identified, where m0 is the free electron mass, and the Fermi surface has been shown to be ellipsoidal. The electron density derived from these dispersions was found to be 3.58e20 cm-3. These findings provide a comprehensive picture of the conduction-band electronic structure that will be crucial in the design of STO-based functional devices.
Materials Science (cond-mat.mtrl-sci)
Silver Electrodeposition from Ag/AgCl Electrodes: Implications for Nanoscience
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-23 20:00 EDT
Chuhongxu Chen, Ziwei Wang, Guilin Chen, Zhijia Zhang, Zakhar Bedran, Stephen Tipper, Pablo Dıaz-Nunez, Ivan Timokhin, Artem Mishchenko, Qian Yang
With the advancement of nanoscience, silver/silver chloride (Ag/AgCl) electrodes have become widely utilised in microscale and nanoscale fluidic experiments, because of their stability. However, our findings reveal that the dissolution of AgCl from the electrode in \ch{Cl-}-rich solutions can lead to significant silver contamination, through the formation of silver complexes, \ch{[AgCl_{n+1}]^{n-}}. We demonstrate the electrodeposition of silver particles on graphene in KCl aqueous solution, with AgCl dissolution from the electrode as the sole source of silver. This unexpected electrodeposition process offers a more plausible interpretation of the recently reported ionic flow-induced current in graphene''. That is, the measured electronic current in graphene is due to the electrodeposition of silver, challenging the previously claimed ionic Coulomb drag’’. More caution is called for when using Ag/AgCl electrodes in microfluidic, and especially nanofluidic systems, because AgCl dissolution should not be neglected.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Chemical Physics (physics.chem-ph)
Major issues in theory of Bose-Einstein condensation
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-23 20:00 EDT
Major issues arising in the theory of Bose-Einstein condensation are reviewed. These issues, although being principally important, are very often misunderstood, which results in wrong conclusions. The basic point is global gauge symmetry breaking that is a necessary and sufficient condition for Bose-Einstein condensation. Paying no attention to this basic point is a common fallacy leading to a number of confusions. For instance, the attempt of describing Bose condensation without gauge symmetry breaking produces the so-called grand canonical catastrophe" that actually does not exist in the correct description of Bose condensation accompanied by gauge symmetry breaking. The other common flaw is forgetting to consider the stability of the studied systems. One sometimes accomplishes lengthy calculations and discusses the properties of a system that in reality cannot exist being unstable. In some cases, the seeming instability is caused by the negligence of the simple mathematical reason teaching us that one should not go beyond the approximation applicability. An example of such an artificial instability is related to the appearance of the so-called thermodynamically anomalous fluctuations” whose arising is due to the use of a second-order approximation for calculating fourth-order terms, in this way distorting the $ O(2)$ -class model of a Bose-condensed system to the Gaussian-class model. These and other principal points, important for the correct treatment of Bose-condensed systems, are reviewed, including the resolution of the Hohenberg-Martin dilemma of gapless versus conserving theories for Bose-condensed systems and the problem of statistical ensemble equivalence.
Quantum Gases (cond-mat.quant-gas), Statistical Mechanics (cond-mat.stat-mech)
Review, 40 pages, 2 figures
AVS Quantum Sci. 7 (2025) 023501
Fast and high-fidelity transfer of edge states via dynamical control of topological phases and effects of dissipation
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-23 20:00 EDT
Yuuki Kanda, Yusuke Fujisawa, Kousuke Yakubo, Norio Kawakami, Hideaki Obuse
Topological edge states are robust against symmetry-preserving perturbations and noise, making them promising for quantum information and computation, particularly in topological quantum computation through braiding operations of Majorana quasiparticles. Realizing these applications requires fast and high-fidelity dynamic control of edge states. In this work, we theoretically propose a high-fidelity method for transferring one-dimensional topological edge states by dynamically moving a domain wall between regions of different topological numbers. This method fundamentally relies on Lorentz invariance and relativistic effects, as moving the domain wall at a constant speed results in the problem into the uniform linear motion of a particle obeying a Dirac equation. We demonstrate effectiveness of our method in transferring edge states with high fidelity using a one-dimensional quantum walk with two internal states, which is feasible with current experimental technology. We also investigate how bit and phase-flip dissipation from environment affects transfer efficiency. Remarkably, these dissipation have minimal effects on efficiency at slow and fast transfer limits, respectively, which can be explained by relativistic effects to the edge states.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
9 pages, 4 figures
Exploring magneto-electric coupling through lattice distortions: insights from a pantograph model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-23 20:00 EDT
Daniel C. Cabra, Gerardo L. Rossini
Multiferroic materials exhibit the coexistence of magnetic and electric order.
They are at the forefront of modern condensed matter physics due to their potential applications in next-generation technologies such as data storage, sensors, and actuators.
Despite significant progress, understanding and optimizing the coupling mechanisms between electric polarization and magnetism remain active areas of research.
We review here a series of papers presenting a comprehensive numerical and theoretical exploration of a pantograph mechanism modeling magneto-electric coupling through lattice distortions in low dimensional multiferroic systems.
These works introduce and elaborate a microscopic model where elastic lattice distortions mediate interactions between spin 1/2 magnetic moments and electric dipoles, uncovering novel physics and functionalities.
The model successfully describes ubiquitous phenomena in type II improper multiferroics, particularly when dominant Ising spin components are
introduced through XXZ-type rotational symmetry breaking spin interactions.
We also study more realistic extensions relevant for materials with higher spin magnetic ions and to materials where magnetic couplings draw higher dimensional lattices.
Strongly Correlated Electrons (cond-mat.str-el)
Review submitted to Special Topic: Ferroic Materials, Domains, and Domain Walls: Bridging Fundamentals with Next-Generation Technology - Journal of Applied Physics
To reset or not to reset in a finite domain: that is the question
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-23 20:00 EDT
Gregorio García-Valladares, Antonio Prados, Alessandro Manacorda, Carlos A. Plata
We investigate the search of a target with a given spatial distribution in a finite one-dimensional domain. The searcher follows Brownian dynamics and is always reset to its initial position when reaching the boundaries of the domain (boundary resetting). In addition, the searcher may be reset to its initial position from any internal point of the domain (bulk resetting). Specifically, we look for the optimal strategy for bulk resetting, i.e., the spatially dependent bulk resetting rate that minimizes the average search time. The best search strategy exhibits a second-order transition from vanishing to non-vanishing bulk resetting when varying the target distribution. The obtained mathematical criteria are further analyzed for a monoparametric family of distributions, to shed light on the properties that control the optimal strategy for bulk resetting. Our work paves new research lines in the study of search processes, emphasizing the relevance of the target distribution for the optimal search strategy, and identifies a successful framework to address these questions.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Mathematical Physics (math-ph)
6+12 pages, 3+6 figures
Tailored Vapor Deposition Unlocks Large-Grain, Wafer-Scale Epitaxial Growth of 2D Magnetic CrCl3
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Vivek Kumar, Abhishek Jangid, Manas Sharma, Manvi Verma, Jampala Pasyanthi, Keerthana S Kumar, Piyush Sharma, Emil O. Chiglintsev, Mikhail I. Panin, Sudeep N. Punnathanam, Alexander I. Chernov, Ananth Govind Rajan, Akshay Singh
Two-dimensional magnetic materials (2D-MM) are an exciting playground for fundamental research, and for spintronics and quantum sensing. However, their large-grain large-area synthesis using scalable vapour deposition methods is still an unsolved challenge. Here, we develop a tailored approach for centimetre-scale growth of semiconducting 2D-MM CrCl3 films on mica substrate, via physical vapour transport deposition. A controlled synthesis protocol, enabled via innovations concerning light management, very-high carrier-gas flow, precursor flux, and oxygen/moisture removal, is critical for wafer-scale growth. Optical, stoichiometric, structural, and magnetic characterization identify crystalline, phase-pure 2D-MM CrCl3. Substrate temperature tunes thickness of films from few-layers to tens of nanometres. Further, selective-area growth and large-area transfer are demonstrated. Substrate-dependent growth features are explained by density functional theory and state-of-the-art machine learning interatomic potential-based atomic-scale simulations. This scalable vapour deposition approach can be applied for growth of several 2D-MM, and low growth temperature (~500 C) will enable creation of hybrid heterostructures.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
62 pages, 5 figures (main text), 15 figures and 3 tables (supplementary)
Very persistent random walkers reveal transitions in landscape topology
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-23 20:00 EDT
We study the typical behavior of random walkers on the microcanonical configuration space of mean-field disordered systems. Passive walks have an ergodicity-breaking transition at precisely the energy density associated with the dynamical glass transition, but persistent walks remain ergodic at lower energies. In models where the energy landscape is thoroughly understood, we show that, in the limit of infinite persistence time, the ergodicity-breaking transition coincides with a transition in the topology of microcanonical configuration space. We conjecture that this correspondence generalizes to other models, and use it to determine the topological transition energy in situations where the landscape properties are ambiguous.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Statistical Mechanics (cond-mat.stat-mech)
Effect of spark plasma sintering on the superconducting properties of Sm-based oxypnictide
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
Mohammad Azam, Tatiana Zajarniuk, Konrad Kwatek, Paolo Mele, Shiv J. Singh
We optimize the superconducting properties of Sm-based oxypnictide (Sm1111: SmFeAsO0.80F0.20) by using the Spark Plasma Sintering (SPS) technique under various synthesis conditions, including heating temperatures ranging from 600 to 1000 °C for durations of 5 to 30 minutes at the applied pressure of 45 MPa. All prepared bulks are characterized by structural and microstructural analysis as well as transport and magnetic measurements to conclude our findings. SmFeAsO0.80F0.20 bulks are also prepared using the conventional synthesis process at ambient pressure (CSP) and the high gas pressure and high temperature (HP-HTS) methods at 500 MPa, which exhibit a superconducting transition temperature (Tc) of ~54 K. Interestingly, the SPS process of SmFeAsO0.80F0.20 increases the sample densities up to 97-98% and confirms the optimized synthesis conditions of 900°C for 5-10 min; however, the increased sintering temperature or duration reduces Tc due to the possible evaporation of lighter elements, particularly fluorine. Furthermore, the SPS technique is unable to reduce the observed impurity phases for the Sm1111, which is similar to the CSP and HP-HTS processes. A slight increment in the Jc by the SPS process is observed due to the enhancement of sample density. A comparative analysis of Sm1111 superconductors prepared by SPS is performed with CSP and HP-HTS processes, suggesting that an increased sample density is ineffective on the superconducting properties in the presence of the impurity phases. This finding can be beneficial for the fundamental and applied research of iron-based superconductor (FBS).
Superconductivity (cond-mat.supr-con), Materials Science (cond-mat.mtrl-sci), Strongly Correlated Electrons (cond-mat.str-el)
40 Pages, 10 Figures, 4 tables
Morphological stability of Au-metal nanosatellites
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-23 20:00 EDT
Sofia Zinzani, Robert M. Jones, Mirko Vanzan, Francesca Baletto
Hybrid metallic nanoalloys combining plasmonic and catalytic metals are essential for developing advanced photocatalysts. A promising design called core-satellites comprises a spherical nanogold dotted with smaller transition-metal clusters. While these nanoalloys’ catalytic activity and hot-carriers generation have been extensively studied, their morphological stability remains poorly explored. Performing molecular dynamics simulations, we highlight the critical role of the transition metal in governing the morphological stability of plasmonic core-satellites. Rh satellites exhibit the highest stability, while only 27% Pt and 16% Pd satellites survive after 200 ns at 600K. AuPt and AuPd quickly rearrange into single spherical nanostructures. AuPt forms icosahedra with an Au outer shell due to Au’s surface diffusion. AuPd favors FCC and decahedral shapes and shows the highest Au mobility and significant Pd interdiffusion. In contrast, AuRh maintains its original shape, exhibiting a slow surface diffusion of gold onto rhodium and negligible mixing.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci)
21 pages, 4 figures
Tracking shear mode dynamics across the glass transition in a 2D colloidal system
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-23 20:00 EDT
Jimin Bai, Peter Keim, Matteo Baggioli
Long-wavelength collective shear dynamics are profoundly different in solids and liquids. According to the theoretical framework developed by Maxwell and Frenkel, collective shear waves vanish upon melting by acquiring a characteristic wave-vector gap, known as the $ k$ -gap. While this prediction has been supported by numerous simulations, experimental validation remains limited. In this work, we track the dispersion relation of collective shear modes in a two-dimensional colloidal system and provide direct experimental evidence for the emergence of a $ k$ -gap. This gap appears at an effective temperature consistent with the onset of the glass transition and the vanishing of the static shear modulus. Our results not only confirm the predictions of the Maxwell-Frenkel framework but also highlight their relevance across continuous melting processes originating from low-temperature amorphous solid phases.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech)
v1: comments welcome
Quantum melting of generalized electron crystal in twisted bilayer MoSe2
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-23 20:00 EDT
Qi Jun Zong, Haolin Wang, Qi Zhang, Xinle Cheng, Yangchen He, Qiaoling Xu, Ammon Fischer, Kenji Watanabe, Takashi Taniguchi, Daniel A. Rhodes, Lede Xian, Dante M. Kennes, Angel Rubio, Geliang Yu, Lei Wang
Electrons can form an ordered solid crystal phase ascribed to the interplay between Coulomb repulsion and kinetic energy. Tuning these energy scales can drive a phase transition from electron solid to liquid, i.e. melting of Wigner crystal. Generalized Wigner crystals (GWCs) pinned to moire superlattices have been reported by optical and scanning-probe-based methods. Using transport measurements to investigate GWCs is vital to a complete characterization, however, still poses a significant challenge due to difficulties in making reliable electrical contacts. Here, we report the electrical transport detection of GWCs at fractional fillings nu = 2/5, 1/2, 3/5, 2/3, 8/9, 10/9, and 4/3 in twisted bilayer MoSe2. We further observe that these GWCs undergo continuous quantum melting transitions to liquid phases by tuning doping density, magnetic and displacement fields, manifested by quantum critical scaling behaviors. Our findings establish twisted bilayer MoSe2 as a novel system to study strongly correlated states of matter and their quantum phase transitions.
Strongly Correlated Electrons (cond-mat.str-el)
Probing Superfluidity with Quantum Vortex Necklaces
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-23 20:00 EDT
Andrea Richaud, Pietro Massignan
We present a method for measuring the superfluid fraction of a Bose-Einstein condensate (BEC) without relying on external perturbations or imposed optical lattices. Our approach leverages the intrinsic rotation of vortex necklaces in one component of a binary superfluid mixture, where the vortex cores act as effective potential wells for the second component. The rotation of the vortex necklace transfers angular momentum to the latter, enabling a direct determination of its effective moment of inertia. Comparing this value with its classical counterpart allows us to extract the superfluid fraction, which we find to be precisely bracketed by the Leggett bounds. By increasing intercomponent interactions, the second component undergoes a crossover from a delocalized and fully superfluid state to an insulating state consisting of a regular array of localized density peaks. Furthermore, the dynamical instability of vortex necklaces provides a natural framework for investigating superfluidity in dynamically evolving and disordered landscapes.
Quantum Gases (cond-mat.quant-gas)
8 pages, 5 figures
Emergent Orbital Dynamics in Strongly Spin-Orbit Coupled Systems
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-05-23 20:00 EDT
The interplay between spin and orbital degrees of freedom gives rise to a variety of emergent phases in correlated 4d and 5d transition-metal systems. Strong spin-orbit coupling (SOC) significantly modifies Jahn-Teller (JT) physics, often suppressing static distortions or promoting dynamic fluctuations, thereby reducing or even quenching orbital polarization. While intersite hybridization is a fundamental aspect of crystalline solids, its role in shaping the dynamics of spin-orbital entangled states has received comparatively little attention. Remarkably, our analysis shows that electronic hopping can locally restore orbital polarization when the ground state is perturbed, potentially leaving measurable fingerprints in the spectra of spin-orbital excitations. Using a Matsubara lattice formalism, we study how local orbital perturbations propagate through correlated, spin-orbit-entangled systems. When intersite hopping is included, such perturbations induce shortrange orbital polarization with a characteristic orthogonal response at nearest-neighbor sites. These hopping-mediated reconstructions may contribute to low-energy spectroscopic signals, potentially overlapping with other excitations, and underscore the importance of including orbital dynamics in the interpretation of spectral data. Our results provide guidance for identifying such signatures and offer a framework for understanding dynamical responses in spin-orbit-entangled materials.
Strongly Correlated Electrons (cond-mat.str-el)
21 pages, 8 figures
Monte Carlo approach to quantum work in strongly correlated electron systems
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-23 20:00 EDT
Qian-Xi Zhao, Jian-Jun Dong, Zi-Xiang Hu
We develop a Monte Carlo framework to analyze the statistics of quantum work in correlated electron systems. Using the Ising-Kondo model in heavy fermions as a paradigmatic platform, we thoroughly illustrate the process of determining the moment generating function of quantum work under nonequilibrium conditions in detail. Based on this function, we systematically investigate essential statistical quantities, including the mean irreversible work density, the mean work density, variance, and the third central moment of quantum work across different quench processes. Our findings highlight distinct singularities in these quantities at the metal-insulator phase transition point at low temperatures. However, these singularities disappear, and the transition becomes a smooth crossover at high temperatures. This stark contrast underscores quantum work as an effective thermodynamic tool for identifying metal-insulator phase transitions. Our approach provides a promising new framework for investigating nonequilibrium quantum thermodynamics in strongly correlated electron systems.
Statistical Mechanics (cond-mat.stat-mech)
6 pages, 3 figures
Dissipatively dressed quasiparticles in boundary driven integrable spin chains
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-05-23 20:00 EDT
Vladislav Popkov, Xin Zhang, Carlo Presilla, Tomaž Prosen
The nonequilibrium steady state (NESS) of integrable spin chains experiencing strong boundary dissipation is accounted by introducing quasiparticles with a renormalized – dissipatively dressed – dispersion relation. This allows us to evaluate the spectrum of the NESS in terms of the Bethe ansatz equations for a related coherent system which has the same set of eigenstates, the so-called dissipation-projected Hamiltonian. We find explicit analytic expressions for the dressed energies of the XXX and XXZ models with effective, i.e., induced by the dissipation, diagonal boundary fields, which are U(1) invariant, as well as the XXZ and XYZ models with effective non-diagonal boundary fields. In all cases, the dissipative dressing generates an extra singularity in the dispersion relation, substantially altering the NESS spectrum with respect to the spectrum of the corresponding coherent model.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph), Quantum Physics (quant-ph)
10+6 pages. This is a companion paper to arXiv.2408.09302
Phase engineering of MoS$_2$ monolayers: A pathway to enhanced lithium-polysulfide battery performance
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
J. W. González, E. Flórez, R. A. Gallardo, J. D. Correa
This study explores the potential of MoS$ _2$ polymorphs, specifically the semiconducting 2H phase and the metallic 1T$ ^\prime$ phase, as anchoring materials to enhance the electrochemical performance of lithium-sulfur (Li-S) batteries. Using density functional theory calculations, we show that 1T$ ^\prime$ -MoS$ _2$ exhibits stronger Li-S interactions, greater charge transfer, and enhanced catalytic activity compared to its 2H counterpart, effectively suppressing polysulfide dissolution and facilitating redox reactions. The reversible 2H$ \leftrightarrow$ 1T$ ^\prime$ transition offers a tunable design space for balancing conductivity and structural stability. These findings position hybrid MoS$ _2$ architectures as promising platforms for next-generation Li-S batteries with improved energy density, cycling stability, and rate capability.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 7 figures
Synthesis of Y$_3$Fe$4$H${20}$ as a new prototype structure for ternary superhydrides recoverable at ambient pressure
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
M. Caussé, L. Toraille, G. Geneste, P. Loubeyre
Reaching pressures in the 100 GPa range enables the synthesis of hydrogen-rich compounds, with nontraditional H stoichiometries and H sublattices, called superhydrides. Record-breaking superconductivity temperature in some superhydrides have attracted great interest. A crucial next step is to stabilize superhydrides outside of high-pressure environments, leading to a search beyond binary hydrides to ternary hydrides. Here, we report the synthesis of Y$ _3$ Fe$ _4$ H$ _{20}$ at pressures starting at 60 GPa by compressing an hydrogenated Y-Fe compound, embedded in hydrogen in a laser-heated diamond anvil cell. Single-crystal X-ray diffraction allowed us to resolve the Y$ _3$ Fe$ _4$ lattice skeleton, and a constrained ab initio structural search was used to position the hydrogen atoms. FeH$ _8$ cubic molecular units form building blocks which are connected edge-to-edge by sharing two hydrogen atoms, creating a framework that hosts Y cations. Remarkably, Y$ _3$ Fe$ _4$ H$ _{20}$ maintains its structure through decompression, making it the first superhydride recovered metastable under ambient conditions.
Materials Science (cond-mat.mtrl-sci), Other Condensed Matter (cond-mat.other), Superconductivity (cond-mat.supr-con)
34 pages, 5 figures
Interfacial Effects Determine Nonequilibrium Phase Behaviors in Chemically Driven Fluids
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-23 20:00 EDT
Yongick Cho, William M. Jacobs
Coupling between chemical fuel consumption and phase separation can lead to condensation at a nonequilibrium steady state, resulting in phase behaviors that are not described by equilibrium thermodynamics. Theoretical models of such “chemically driven fluids” typically invoke near-equilibrium approximations at small length scales. However, because dissipation occurs due to both molecular-scale chemical reactions and mesoscale diffusive transport, it has remained unclear which properties of phase-separated reaction-diffusion systems can be assumed to be at an effective equilibrium. Here we use microscopic simulations to show that mesoscopic fluxes are dependent on nonequilibrium fluctuations at phase-separated interfaces. We further develop a first-principles theory to predict nonequilibrium coexistence curves, localization of mesoscopic fluxes near phase-separated interfaces, and droplet size-scaling relations in good agreement with simulations. Our findings highlight the central role of interfacial properties in governing nonequilibrium condensation and have broad implications for droplet nucleation, coarsening, and size control in chemically driven fluids.
Soft Condensed Matter (cond-mat.soft), Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
Includes Supplementary Information
First-principles study of metal-biphenylene interfaces: structural, electronic, and catalytic properties
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Maicon P. Lebre, Dominike Pacine, Erika N. Lima, Alexandre A. C. Cotta, Igor S. S. de Oliveira
We employ first-principles density functional theory (DFT) calculations to investigate the structural, electronic, and catalytic properties of biphenylene supported on various metal substrates. The substrates considered are the (111) surfaces of Ag, Au, Ni, Pd, Pt, Cu, Al, and the Cu$ _3$ Au alloy. Our results reveal how the interaction between biphenylene and the substrate governs its stability, degree of corrugation, electronic hybridization, and interfacial charge transfer. In particular, we observe a clear trend where weakly interacting metals preserve the intrinsic features of biphenylene, while more reactive substrates lead to significant structural and electronic modifications. We further evaluate the hydrogen evolution reaction (HER) activity of these systems, showing that certain metal supports, especially Pd, Pt, Ag, and Cu, can enhance the catalytic performance of biphenylene. Notably, Ag and Cu combine good catalytic activity with lower cost and chemical stability, offering a promising balance for practical applications. These findings provide insights into the design of biphenylene-metal interfaces, supporting their use in next-generation electronic and catalytic devices.
Materials Science (cond-mat.mtrl-sci)
Improvement of H2O2 electrogeneration using a Vulcan XC72 carbon-based electrocatalyst modified with Ce-doped Nb2O5
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Aline B. Trench, João Paulo C. Moura, Vanessa S. Antonin, Caio Machado Fernandes, Liying Liu, Mauro C. Santos
The use of the oxygen reduction reaction (ORR) for in-situ production of H2O2 is an attractive alternative to replace the methods based on anthraquinone oxidation. This study investigates the modification of Vulcan XC72 carbon with Ce-doped Nb2O5 in different molar proportions and its application as electrocatalysts in the ORR. One performed the characterization of the electrocatalysts using X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, contact angle measurements, and X-ray photoelectron spectroscopy. Subsequently, the electrocatalysts were analyzed for the ORR and the Nb2O5 doped with 0.5% Ce showing the highest electrocatalytic response. This electrocatalyst was also employed as a gas diffusion electrode and exhibited more significant H2O2 production at all potentials than the Vulcan XC72 carbon modified solely with Nb2O5. At the applied potentials of -1.3 V and -1.9 V, it produced 105% and 86% more H2O2, respectively, than the Vulcan XC72 carbon modified only with Nb2O5. These results can be attributed to the doping of Nb2O5 with 0.5% Ce, which induces local distortions in the crystal lattice of Nb2O5 due to the difference in ionic radius between Nb5+ and Ce3+, which combined with increased hydrophilicity and wetting properties, may have facilitated electron transfer and O2 transport, favoring the ORR.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
Magnetic vortex writing and local reversal seeding in artificial spin-vortex ice via all-optical and surface-probe control
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-05-23 20:00 EDT
Holly Holder, Jack C. Gartside, Alex Vanstone, Troy Dion, Xiaofei Xiao, Kilian D. Stenning, Tingjun Zheng, Daniel Bromley, Tobias Farchy, Rupert F. Oulton, Will R. Branford
Artificial spin-vortex ice (‘ASVI’) is a reconfigurable nanomagnetic metamaterial consisting of magnetic nanoislands tailored to support both Ising macrospin and vortex textures. ASVI has recently shown functional applications including reconfigurable magnonics and neuromorphic computing, where the introduction of vortex textures broadens functionality beyond conventional artificial spin ice which generally supports macrospin states. However, local control of writing vortex states in ASVI remains an open challenge. Here we demonstrate techniques for field-free magnetic vortex writing in ASVI. We expand ASVI to support metastable macrospin, single-vortex and double-vortex states. All-optical writing via focused laser illumination can locally write double-vortex textures, and surface-probe writing using an MFM tip can locally write single vortex states. We leverage this writing to tailor and explore the reconfigurable energy landscape of ASVI, demonstrating programmable local seeding of avalanche-like reversal events. The global field-free texture selective writing techniques reported here expand the suite of nanomagnetic control techniques, with a host of future applications including fundamental studies of avalanche dynamics, physical memory, and direct writing of nanomagnetic ‘weights’ in physical neuromorphic neural networks.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Bose-Einstein condensation in exotic lattice geometries
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-23 20:00 EDT
Kamil Dutkiewicz, Marcin Płodzień, Abel Rojo-Francàs, Bruno Juliá-Díaz, Maciej Lewenstein, Tobias Grass
Modern quantum engineering techniques allow for synthesizing quantum systems in exotic lattice geometries, from self-similar fractal networks to negatively curved hyperbolic graphs. We demonstrate that these structures profoundly reshape Bose-Einstein condensation. Fractal lattices dramatically lower the condensation temperature, while hyperbolic lattices cause it to increase as the system grows - a behavior not seen in ordinary two-dimensional arrays, where the condensation temperature vanishes in the large-size limit. The underlying geometry also controls condensate fluctuations, enhancing them on fractal networks but suppressing them on hyperbolic graphs compared with regular one-dimensional or two-dimensional lattices. When strong repulsive interactions are included, the gas enters a Mott insulating state. A multi-site Gutzwiller approach finds a smooth interpolation between the characteristic insulating lobes of one-dimensional and two-dimensional systems. Re-entrant Mott transitions are seen within a first-order resummed hopping expansion. Our findings establish lattice geometry as a powerful tuning knob for quantum phase phenomena and pave the way for experimental exploration in photonic waveguide arrays and Rydberg-atom tweezer arrays.
Quantum Gases (cond-mat.quant-gas), Quantum Physics (quant-ph)
Hydrogen peroxide electrogeneration from O2 electroreduction: a review focusing on carbon electrocatalysts and environmental applications
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Aline B. Trench, Caio Machado Fernandes, João Paulo C. Moura, Lanna E. B. Lucchetti, Thays S. Lima, Vanessa S. Antonin, James M. de Almeida, Pedro Autreto, Irma Robles, Artur J. Motheo, Marcos R. V. Lanza, Mauro C. Santos
Hydrogen peroxide (H2O2) stands as one of the foremost utilized oxidizing agents in modern times. The established method for its production involves the intricate and costly anthraquinone process. However, a promising alternative pathway is the electrochemical hydrogen peroxide production, accomplished through the oxygen reduction reaction via a 2-electron pathway. This method not only simplifies the production process but also upholds environmental sustainability, especially when compared to the conventional anthraquinone method. In this review paper, recent works from the literature focusing on the 2-electron oxygen reduction reaction promoted by carbon electrocatalysts are summarized. The practical applications of these materials in the treatment of effluents contaminated with different pollutants (drugs, dyes, pesticides, and herbicides) are presented. Water treatment aiming to address these issues can be achieved through advanced oxidation electrochemical processes such as electro-Fenton, solar-electro-Fenton, and photo-electro-Fenton. These processes are discussed in detail in this work and the possible radicals that degrade the pollutants in each case are highlighted. The review broadens its scope to encompass contemporary computational simulations focused on the 2-electron oxygen reduction reaction, employing different models to describe carbon-based electrocatalysts. Finally, perspectives and future challenges in the area of carbon-based electrocatalysts for H2O2 electrogeneration are discussed. This review paper presents a forward-oriented viewpoint of present innovations and pragmatic implementations, delineating forthcoming challenges and prospects of this ever-evolving field.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
Higher order Jacobi method for solving a system of linear equations
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
Nithin Kumar Goona, Lama Tarsissi
This work proposes a higher-order iterative framework for solving matrix equations, inspired by the structure and functionality of neural networks. A modification of the classical Jacobi method is introduced to compute higher-order coefficient matrices through matrix-matrix multiplications. The resulting method, termed the higher-order Jacobi method, structurally resembles a shallow linear network and allows direct computation of the inverse of the coefficient matrix. Building on this, an iterative scheme is developed that, once the network parameters are determined for a known system, enables efficient resolution of system variations without re-computing the coefficients. This iterative process naturally assumes the form of a deep recurrent neural network. The proposed approach moves beyond conventional Physics-Informed Neural Networks (PINNs) by providing an explicit, training-free definition of network parameters rooted in physical and mathematical formulations. Computational analysis demonstrates improved order of complexity, suggesting a promising direction for algorithmic efficiency in solving linear systems. This methodology opens avenues for interpretable and scalable solutions to physically motivated problems in computational science.
Superconductivity (cond-mat.supr-con), Computational Physics (physics.comp-ph)
12 pages, 3 figures
Photo-induced electronic excitations drive polymerization of carbon monoxide: A first-principles study
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-05-23 20:00 EDT
Rasool Ahmad, Jonathan C. Crowhurst, Stanimir A. Bonev
Under pressure, carbon monoxide (CO) transforms into a polymer that can be recovered to ambient conditions. While this transformation can occur without additional stimuli, experimental observations have shown that laser irradiation can induce a similar transformation at reduced pressure. The resulting polymeric phase, which is metastable under ambient conditions, releases energy through decomposition into more stable configurations. Using time-dependent density functional theory and Born-Oppenheimer molecular dynamics simulations, we investigate the mechanism by which electronic excitation facilitates CO polymerization. Our calculations reveal that electronic excitation enhances carbon-carbon bonding, enabling polymerization at pressures significantly lower than those required by conventional compression methods. These findings suggest that a photo-assisted approach could be employed to synthesize novel, potentially energetic materials under less demanding pressure conditions.
Materials Science (cond-mat.mtrl-sci)
Lorentz-violating QED inspired superconductivity
New Submission | Superconductivity (cond-mat.supr-con) | 2025-05-23 20:00 EDT
A.F.Morais, M.C.Araújo, T.T.Saraiva, J. Furtado
We studied a Lorentz-violating inspired Ginzburg-Landau model for superconductivity where we considered a CPT-odd contribution given by $ (k_{AF})^{\mu}$ , also known as the Carroll-Field-Jackiw term. In the static limit of the equations, we could find a pair of modified Ginzburg-Landau equations. Furthermore, these equations were reduced to the London equation for the magnetic field when assumed that the characteristic length of the order parameter is much smaller than the characteristic length of the magnetic field, i.e. the London penetration length. Our numerical solutions showed a simple Meissner state when this new term is small compared to $ \lambda_L$ and a phase transition into phases with strong in-plane currents and anomalous vortices for large contributions. This model becomes useful in exemplifying the changes in the phenomenology of superconductors when the setup of the system shows an important breakdown of Lorentz invariance. Based on these results, we discuss how such models might be the hallmark of unusual superconducting states where there is a direction where the system shows stratification, as in anapole superconductors UTe$ _2$ .
Superconductivity (cond-mat.supr-con), High Energy Physics - Theory (hep-th)
8 pagens, 3 figures
Sliding Friction of Hard Sliders on Rubber: Theory and Experiment
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-05-23 20:00 EDT
We present a study of sliding friction for rigid triangular steel sliders on soft rubber substrates under both lubricated and dry conditions. For rubber surfaces lubricated with a thin film of silicone oil, the measured sliding friction at room temperature agrees well with theoretical predictions obtained from a viscoelastic model originally developed for rolling friction. On the lubricated surface, the sliding friction is primarily due to bulk viscoelastic energy dissipation in the rubber. The model, which includes strain-dependent softening of the rubber modulus, accurately predicts the experimental friction curves. At lower temperatures ($ T = -20^\circ {\rm C}$ and $ -40^\circ {\rm C}$ ), the measured friction exceeds the theoretical prediction. We attribute this increase to penetration of the lubricant film by surface asperities, leading to a larger adhesive contribution. For dry surfaces, the adhesive contribution becomes dominant. By subtracting the viscoelastic component inferred from the lubricated case, we estimate the interfacial frictional shear stress. This shear stress increases approximately linearly with the logarithm of the sliding speed, consistent with stress-augmented thermal activation mechanisms.
Soft Condensed Matter (cond-mat.soft)
Nonlinear thermal and thermoelectric transport from quantum geometry
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-05-23 20:00 EDT
Yuan Fang, Shouvik Sur, Yonglong Xie, Qimiao Si
Quantum geometry may enable the development of quantum phases ranging from superconductivity to correlated topological states. One powerful probe of quantum geometry is the nonlinear Hall response which detects Berry curvature dipole in systems with time-reversal invariance and broken inversion symmetry. With broken time-reversal symmetry, this response is also associated with quantum metric dipole. Here we investigate nonlinear thermal and thermoelectric responses, which provide a wealth of new information about quantum geometry. In particular, we uncover a web of connections between these quantities that parallel the standard Wiedemann-Franz and Mott relations. Implications for the studies of a variety of topological systems, including Weyl-Kondo semimetals and Bernal bilayer graphene, are discussed.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
7+14 pages, 2+7 figures
Topological Phases, Criticality, and Mixed State Order in a Hubbard Quantum Simulator
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-05-23 20:00 EDT
Lin Su, Rahul Sahay, Michal Szurek, Alexander Douglas, Ognjen Markovic, Ceren B. Dag, Ruben Verresen, Markus Greiner
Phases of matter are conventionally distinguished from one another by local observables. Topological quantum phases lie outside this paradigm; their differences can only be learned by examining them globally. This has striking implications for the stability of these phases, their classification, and the phase transitions between them. In this work, we experimentally demonstrate these implications using interacting magnetic erbium atoms in an optical lattice. We show that a Mott insulator and a pinned charge-density wave in one dimension are in distinct crystalline symmetry-protected topological phases (CSPTs). The quantum phase transition separating them is revealed by measuring nonlocal string order parameters using site-resolved imaging. Remarkably, stacking two copies of these states eliminates the critical point – a signature feature of topological phases that underlies their classification. Moreover, we show that while a programmable symmetry-breaking disorder pattern can also remove this critical point, averaging over disorder restores it, supporting recent theoretical predictions of mixed-state order. Finally, we highlight a connection between one of these CSPTs and the Haldane insulator, and detect signatures of the transition between the Haldane and the Mott insulator. Our results establish a path toward probing broader symmetry-protected topology and mixed-state order in programmable quantum devices.
Quantum Gases (cond-mat.quant-gas), Strongly Correlated Electrons (cond-mat.str-el), Atomic Physics (physics.atom-ph), Quantum Physics (quant-ph)