Materials Science
Local Multimodal Dynamics in Mixed Ionic-Electronic Conductors and Their Fingerprints in Organic Electrochemical Transistor Operation
Shubham Tanwar, Han-Yan Wu, Chi-Yuan Yang et al. (+4 more)
Mixed ionic-electronic conductors host tightly coupled interactions among mobile ions, electronic charges, and the
polymer matrix, giving rise to complex
multimodal responses spanning electrical, mechanical, and morphological transformations. These materials underpin organic electrochemical transistors (OECTs), which translate such interactions into low-voltage signal amplification and sensing for applications in bioelectronics, neuromorphic computing, and
memory. Despite their central role, OECT current-voltage transfer characteristics are often treated phenomenologically, as both the local
multimodal dynamics and their connection to global device response remain unresolved. Here, we reveal that the transfer curve encodes a cascade of spatially localized electrochemical transitions, each associated with distinct changes in conductivity, stiffness, and morphology, fundamentally redefining it as a spatially resolved fingerprint of device's internal state. Using automated operando
multimodal in-
liquid scanning dielectric microscopy, we directly map these dynamics and identify region-specific electrochemical thresholds governing the interplay between source, channel, and drain. We found that the local tip-sample electrostatic force serves as a remarkable mechanistic observable of coupled
multimodal dynamics in mixed conductors. A physically grounded model links it to general material, interfacial, and
geometric parameters, enabling mechanistic interpretation and predictive insights. Our work provides a new framework for probing and understanding mixed conduction in ion-electron coupled systems.
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All authors Shubham Tanwar, Han-Yan Wu, Chi-Yuan Yang, Ruben Millan-Solsona, Simone Fabiano, Adrica Kyndiah, Gabriel Gomila
Disordered Systems and Neural Networks
Beyond the imbalance: site-resolved dynamics probing resonances in many-body localization
Asmi Haldar, Thibault Scoquart, Fabien Alet et al. (+1 more)
We explore the limitations of using imbalance dynamics as a diagnostic tool for many-body localization (MBL) and show that spatial averaging can mask important microscopic features. Focusing on the strongly disordered regime of the random-field XXZ chain, we use state-of-the-art numerical techniques (Krylov time
evolution and full diagonalization) to demonstrate that site-resolved
spin autocorrelators reveal a rich and complex dynamical behavior that is obscured by the imbalance observable. By analyzing the time
evolution and infinite-time limits of these local probes, we reveal resonant structures and rare local instabilities within the MBL phase. These numerical findings are supported by an analytical, few-site toy model that captures the emergence of a multiple-peak structure in local magnetization histograms, which is a hallmark of local resonances. These few-body local effects provide a more detailed understanding of ergodicity-breaking dynamics, and also allow us to explain the finite-size effects of long-time imbalance, and its sensitivity to the initial conditions in quench protocols. Overall, our experimentally testable predictions highlight the necessity of a refined, site-resolved approach to fully understand the complexities of MBL and its connection to rare-region effects.
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All authors Asmi Haldar, Thibault Scoquart, Fabien Alet, Nicolas Laflorencie
Materials Science · Cross-listed from quant-ph
Quantum Elastic Network Models and their Application to Graphene
Ioannis Kolotouros, Adithya Sireesh, Stuart Ferguson et al. (+3 more)
Molecular dynamics simulations are a central computational methodology in materials design for relating atomic composition to mechanical properties. However, simulating materials with atomic-level resolution on a macroscopic scale is infeasible on current classical hardware, even when using the simplest elastic network models (ENMs) that represent molecular vibrations as a network of coupled oscillators. To address this issue, we introduce
Quantum Elastic Network Models (QENMs) and utilize the
quantum algorithm of Babbush et al. (PRX, 2023), which offers an exponential advantage when simulating systems of coupled oscillators. Here, we extend their
algorithm in 2D systems and demonstrate how our method enables the efficient simulation of planar materials. As an example, we apply our
algorithm to the task of simulating a 2D
graphene sheet. We analyze the complexity for initial-state preparation,
Hamiltonian simulation, and measurement of this material, and provide two real-world applications: heat transfer and the out-of-plane rippling effect. We estimate that an atomistic simulation of a
graphene sheet on the centimeter scale, classically requiring hundreds of petabytes of
memory and prohibitive runtimes, could be encoded and simulated with as few as $\sim 160$ logical
qubits.
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All authors Ioannis Kolotouros, Adithya Sireesh, Stuart Ferguson, Sean Thrasher, Petros Wallden, Julien Michel
Superconductivity
Low-loss Material for Infrared Protection of Cryogenic Quantum Applications
Markus Griedel, Max Kristen, Biliana Gasharova et al. (+3 more)
The fragile
quantum states of low-temperature
quantum applications require protection from infrared radiation caused by higher-temperature stages or other sources. We propose a material system that can efficiently block radiation up to the optical range while transmitting
photons at low gigahertz frequencies. It is based on the effect that incident
photons are strongly scattered when their wavelength is comparable to the size of particles embedded in a weakly absorbing medium (Mie-scattering). The goal of this work is to tailor the absorption and transmission spectrum of an non-
magnetic epoxy resin containing sapphire spheres by simulating its dependence on the size distribution. Additionally, we fabricate several material compositions, characterize them, as well as other materials, at optical, infrared, and gigahertz frequencies. In the infrared region (stop band) the attenuation of the Mie-scattering optimized material is high and comparable to that of other commonly used filter materials. At gigahertz frequencies (pass-band), the prototype filter exhibits a high transmission at millikelvin temperatures, with an insertion loss of less than $0.4\,$dB below $10\,$GHz.
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All authors Markus Griedel, Max Kristen, Biliana Gasharova, Yves-Laurent Mathis, Alexey V. Ustinov, Hannes Rotzinger
Materials Science
Prediction of Magnetic Topological Materials Combining Spin and Magnetic Space Groups
Liangliang Huang, Yuanze Song, Houhao Wang et al. (+3 more)
Recent developments in
spin space groups (SSGs) have led to a new classification of
magnetic order and, with it, the emergence of altermagnetism. However, an efficient and routine approach that predicts electronic band
topology in
magnetic materials by SSGs, and especially the
evolution of band
topology from negligible spinorbit coupling (SOC) to finite SOC with the
symmetry lowering from SSGs to
magnetic space groups (MSGs) determined by
magnetic-moment directions, has not yet been established. Here, we propose a scheme combining SSG and its MSG subgroups to diagnose band
topology in collinear magnets using
symmetry indicators of electronic band
topology, established for all the 1,421 SSGs and 3,420 MSG subgroups. Specifically, the compatibility relations from SSG to the MSG subgroups can enable a complete topological classification for all possible
magnetic-moment directions from the first-principles calculated numbers of occurrences of irreducible (co-)representations at high-
symmetry points without SOC with respect to SSG. This scheme can be directly applied to collinear magnets whose
magnetic structures have already been determined experimentally or theoretically. Applying it to 488 collinear magnets from MAGNDATA with experimentally determined
magnetic structures, we identify 26 materials that are trivial by MSG but are expected to inherit
topology protected by SSG
symmetry. We showcase Dirac nodal lines and boundary states predicted by SSG but invisible to MSG in FePSe$_3$. Our work demonstrates the predictive power of the approach combining SSG and MSG over the approaches based on either group alone. The results of high-throughput calculations are expected to extend the
magnetic topological materials pool, facilitating future experimental realizations of more
magnetic topological materials.
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All authors Liangliang Huang, Yuanze Song, Houhao Wang, Zhixian Yu, Xiangang Wan, Feng Tang
Quantum Gases · Cross-listed from gr-qc
Superluminal modes in a quantum field simulator for cosmology from analog trans-Planckian physics
Christian F. Schmidt and Stefan Floerchinger
The
quantum-field-theoretic description for the U(1)-Goldstone
boson of a scalar Bose-Einstein condensate with time-dependent contact interactions is developed beyond the acoustic approximation in accordance with Bogoliubov theory. The resulting effective action is mapped to a relativistic
quantum field theory on a dispersive (or rainbow) cosmological spacetime which has a superluminal Corley-Jacobson dispersion relation. Time-dependent changes of the s-wave scattering length to
quantum-simulate cosmological particle production are accompanied by a time-dependent healing length that can be interpreted as an analog Planck length in the comoving frame. Non-adiabatic transitions acquire a dispersive character, which is thoroughly discussed. The framework is applied to exponentially expanding or power-law contracting $(2+1)$-dimensional spacetimes which are known to produce scale-invariant cosmological power spectra. The sensitivity of these scenarios to the time-dependence of the Bogoliubov dispersion is investigated: We find a violation of scale-invariance via analytically trackable Transplanckian damping effects if the cut-off scale is not well separated from the horizon-crossing scale. In case of the exponential expansion, these damping effects remarkably settle and converge to another scale-invariant plateau in the far ultraviolet regime where non-adiabatic transitions are suppressed by the high dispersion. The developed framework enables quantitative access to more drastic analog cosmological scenarios with improved predictability in the ultraviolet regime that ultimately may lead to the observation of a scale-invariant cosmological power spectrum in the laboratory.
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Strongly Correlated Electrons
Enhanced Electron Reflectionat Mott-Insulator Interfaces
Jan Verlage and Peter Kratzer
The Klein paradox describes an incoming electron being scattered at a supercritical barrier to create electron-positron pairs, a phenomenon widely discussed in textbooks. While demonstrating this phenomenon experimentally with the fundamental particles remains challenging, condensed matter analogs are more accessible to experimental realization. For spinless quasi-particles, theoretical works show an enhancement of the pair production rate, and analogs of this effect in condensed matter systems have been studied theoretically. Here, we present another condensed matter system, a
heterostructure comprised of two materials with strongly and weakly interacting electrons, that allows for constructing analytical solutions using the hierarchy-of-correlations method. The results show enhanced electron reflection related with the production of doublon-holon pairs, as known from the Klein paradox.
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Strongly Correlated Electrons
Acoustic signatures of the field-induced electronic-topological transitions in YbNi$_4$P$_2$
E.-O. Eljaouhari, B. V. Schwarze, K. Kliemt et al. (+6 more)
We investigated the magnetoelastic properties of an YbNi$_4$P$_2$ single
crystal at low temperatures under
magnetic fields directed along the crystallographic [001] axis. We report a series of strong anomalies in the sound velocity, which is consistent with the cascade of electronic-topological transitions reported previously for this compound. In particular, we identify the vanishing of a small orbit on the
Fermi surface, associated with a
quantum-oscillation frequency of 34 T. Furthermore, the different transitions are better resolved with acoustic modes of particular
symmetry. Using a microscopic model adapted to the strongly correlated electronic structure of YbNi$_4$P$_2$, we describe our results by inspecting realistic electron-
phonon couplings in reciprocal space for each acoustic mode. This shows how the $k$ selectivity of ultrasound experiments allows to investigate
Fermi-surface reconstructions in strongly correlated electronic systems.
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All authors E.-O. Eljaouhari, B. V. Schwarze, K. Kliemt, C. Krellner, F. Husstedt, J. Wosnitza, S. Zherlitsyn, G. Zwicknagl, J. Sourd
Materials Science
A First-principles Study of Weyl Nodal Loop and Multiple Sets of Weyl Points in Trigonal PtBi$_2$
Lin-Lin Wang
Coexistence of surface superconductivity and
Fermi arcs in trigonal $\gamma$-PtBi$_2$ has recently attracted
attention for possible realization of topological superconductivity. The
Fermi arcs on the two different (0001) surface terminations have been associated with the set of Weyl points just above the
Fermi energy (E$_F$). Here using first-principles calculations to explore the band crossings over the full Brillouin zone between the nominally highest valence and lowest conduction bands in $\gamma$-PtBi$_2$, we study the Weyl nodal loop (WNL) and multiple sets of Weyl points (WPs). The main difference between the two reported experimental structural parameters is the magnitude of Bi-layer buckling. While the WNL, bulk gap region and the set of Weyl points just above the E$_F$ are robust, the number and location of the other sets of WPs depend sensitively on the structural parameters with different magnitude of Bi-layer buckling. Besides calculating the 2D
Fermi surface with
Fermi arcs and quasi-particle interference (QPI) around the E$_F$ in good agreements with ARPES and experimental QPI, we also predict new
Fermi arc features at higher energy.
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Mesoscale and Nanoscale Physics
Quantum Spin Transfer of Spin-Correlated Electron Pairs
Seongmun Hwang, Jung Hyun Oh, Paul M. Haney et al. (+2 more)
We theoretically investigate
quantum spin transfer from
spin-correlated conduction-electron pairs to localized
spins in a ferromagnet, given that electrons are correlated intrinsically. We show that even
spin-singlet pairs and triplet pairs with $m=0$, both carrying no net
spin, can transfer finite angular momentum through the
quantum fluctuation term inherent to the $sd$ exchange interaction. The amount of transferred
spin differs between the singlet and triplet $m=0$ states due to
quantum interference. The difference is such that the independent-electron approximation remains valid for
spin transfer when injected
spin currents are completely incoherent. However, in partially coherent systems, like
superconductor/ferromagnet junctions, coherent
spin-singlet currents can directly convert into equal-
spin triplet currents in generic ferromagnets, without requiring
magnetic inhomogeniety or
spin-orbit coupling.
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All authors Seongmun Hwang, Jung Hyun Oh, Paul M. Haney, Mark D. Stiles, Kyung-Jin Lee
Materials Science
Hierarchical Crystal Structure Prediction of Zeolitic Imidazolate Frameworks Using DFT and Machine-Learned Interatomic Potentials
Yizhi Xu, Jordan Dorrell, Katarina Lisac et al. (+4 more)
Crystal structure prediction (CSP) is emerging as a powerful method for the computational design of metal-organic frameworks (MOFs). In this article we employ CSP to perform high-throughput exploration of the
crystal energy landscape of zinc imidazolate (ZnIm2). As the most polymorphic member of the zeolitic imidazolate framework (ZIF) family, ZnIm2 has at least 24 reported structural and topological forms, and new polymorphs still being regularly discovered. With the aid of custom-trained machine-learned interatomic potentials (MLIPs) we have performed a high-throughput sampling of over 3 million randomly-generated
crystal packing arrangements and identified 9609 energy minima characterized by 1484 network
topologies, including 855
topologies that have not been reported before. All but one experimentally-reported structures of ZnIm2, falling within the search boundaries, were ultimately matched with the predicted structures, demonstrating the power of the CSP method in sampling experimentally-relevant ZIF structures. Finally, through a combination of topological analysis, density and porosity considerations, we have identified a set of structures representing promising targets for future experimental screening. as well as demonstrated how structures of mechanochemically-synthesized MOFs could be identified via matching experimental powder diffraction patterns with simulated patterns from the predicted structures.
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All authors Yizhi Xu, Jordan Dorrell, Katarina Lisac, Ivana Brekalo, James P. Darby, Andrew J. Morris, Mihails Arhangelskis
Statistical Mechanics
Full counting statistics in the sine-Gordon model
Botond C. Nagy, Márton Kormos and Gábor Takács
Full counting statistics (FCS) is a dynamical generalisation of the free energy, encapsulating detailed information about the distribution and large-scale correlation functions of conserved charges and their associated currents. In this work, we present a comprehensive numerical study of the FCS and the cumulants of the three lowest charges across the full parameter space of the sine-Gordon field theory. To this end, we extend the thermodynamic Bethe Ansatz (TBA) formulation of the FCS to the sine-Gordon model, emphasise the methodological subtleties for a reliable numerical implementation, and compare numerical results with analytical predictions in certain limits.
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Statistical Mechanics · Cross-listed from cs.SI
Graph energy as a measure of community detectability in networks
Lucas Böttcher, Mason A. Porter and Santo Fortunato
A key challenge in network science is the detection of communities, which are sets of nodes in a network that are densely connected internally but sparsely connected to the rest of the network. A fundamental result in community detection is the existence of a nontrivial threshold for community detectability on sparse graphs that are generated by the planted partition model (PPM). Below this so-called “detectability limit”, no community-detection method can perform better than random chance. Spectral methods for community detection fail before this detectability limit because the
eigenvalues corresponding to the eigenvectors that are relevant for community detection can be absorbed by the bulk of the spectrum. One can bypass the detectability problem by using special
matrices, like the non-backtracking
matrix, but this requires one to consider higher-dimensional
matrices. In this paper, we show that the difference in graph energy between a PPM and an Erdős–Rényi (ER) network has a distinct transition at the detectability threshold even for the adjacency
matrices of the underlying networks. The graph energy is based on the full spectrum of an adjacency
matrix, so our result suggests that standard graph
matrices still allow one to separate the parameter regions with detectable and undetectable communities.
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Materials Science
Electrically Controllable Flat Band in Two-Dimensional Electron Gases under Nonuniform Magnetic Fields
You-Ting Huang, Chao-Cheng Kaun and Ching-Hao Chang
Flat bands underlie a diverse range of
quantum phenomena, from strongly correlated phases to superconductivity. We theoretically establish that a two-dimensional electron gas under a linear
magnetic-field gradient and a transverse electric field exhibits electrically tunable flat bands. When the electric field magnitude is tuned to a value within a discrete sequence, these bands become strictly dispersionless. By providing exact classical and
quantum solutions, we demonstrate that these states are high-order Landau levels associated with drift-compensated cyclotron orbits of carriers arising from the synergy between the
magnetic-field gradient and the electric field. These electrically controllable Landau levels exhibit quantized
Hall conductance and a strongly enhanced density of states. Our results provide a new route for flat-band creation, magnetoelectric band engineering, and quantized
Hall currents controlled via source-drain voltage.
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Materials Science
Electronic structure of Sn(1-x)Mn(x)Te semiconducting solid solution: a resonant photoemission study
Elzbieta Guziewicz, Bronislaw A. Orlowski and Bogdan J. Kowalski
Manganese-doped tin telluride, Sn(1-x)Mn(x)Te, initially investigated as diluted
magnetic semiconductor, has recently attracted considerable
attention as a prospective thermoelectric material. The introduction of Mn was found to modify the valence band electronic structure, resulting in an improvement in the Seebeck coefficient and thus, the figure of merit (ZT). In the paper, we present a synchrotron radiation study of the electronic band structure of Sn(0.9)Mn(0.1)Te by resonant photoemission. The contribution of the Mn3d electrons to the valence band (VB), calculated as the difference between the Energy Distribution Curves (EDCs) taken at the maximum and minimum of the Fano resonance for the Mn3p - Mn3d absorption threshold, shows a contribution at the VB edge, a dominant maximum at 4 eV, as well as a wide structure between 7 and 11 eV. Moreover, comparison with undoped SnTe reveals strong renormalization of the Sn5p and Te5p electronic states, which certainly influences the shape of the upper part of the valence band and electron effective mass.
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Materials Science
Correlative Ultrafast Imaging of a Propagating Photo-Driven Phase Transition Using 4D STEM
Arthur Niedermayr, Jianyu Wu, Bertina Fisher et al. (+2 more)
Oxides exhibiting
insulator-metal transitions are promising candidates for next generation ultrafast electronic switching devices. However, critical gaps remain in understanding the onset of strain and its dynamics as these materials undergo structural transitions, particularly in nanostructured configurations. Here, we present ultrafast four-dimensional scanning transmission electron microscopy enabling virtual imaging and strain mapping at every point in space and time. Using this technique, we directly probe a
laser-excited phase transition in the prototypical material vanadium dioxide (VO2), recording its spatiotemporal propagation. This direct imaging capability reveals the dynamics of the structural phase transition and connects it to the resulting strain formation on picosecond timescales. This correlation reveals how atomic-scale
symmetry breaking inherently generates
lattice distortions, which then propagate to govern macroscopic property changes. Our findings provide new insights into the coupling between electronic, structural, and mechanical responses in correlated
oxides under non-
equilibrium conditions.
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All authors Arthur Niedermayr, Jianyu Wu, Bertina Fisher, Ido Kaminer, Jonas Weissenrieder
Materials Science
Stable Machine Learning Potentials for Liquid Metals via Dataset Engineering
Alex Tai, Jason Ogbebor and Rodrigo Freitas
Liquid metals are central to energy-storage and
nuclear technologies, yet quantitative knowledge of their thermophysical properties remains limited. While atomistic simulations offer a route to computing
liquid properties directly from atomic motion, the most accurate approach, ab initio molecular dynamics (AIMD), is computationally costly and restricted to short time and length scales. Machine learning interatomic potentials (MLPs) offer AIMD accuracy at far lower cost, but their application to
liquids is limited by training
datasets that inadequately sample atomic configurations, leading to unphysical force predictions and unstable trajectories. Here we introduce a physically motivated
dataset-engineering strategy that constructs liquidlike training data synthetically rather than relying on AIMD configurations. The method exploits the established icosahedral short-range order of metallic
liquids, twelvefold, near-close-packed local coordination, and generates "synthetic-
liquid" structures by systematic perturbation of crystalline references. MLPs trained on these
datasets close the sampling gaps that lead to unphysical predictions, remain numerically stable across temperatures, and reproduce experimental
liquid densities, diffusivities, and melting temperatures for multiple elemental metals. The framework links atomic-scale sampling to long-term MD stability and provides a practical route to predictive modeling of
liquid-phase thermophysical behavior beyond the limits of direct AIMD.
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Strongly Correlated Electrons
Kitaev interactions in the van der Waals antiferromagnet VBr3
Zeyu Kao, Yimeng Gu, Yiqing Gu et al. (+5 more)
Van der Waals materials hosting Kitaev interactions are promising platforms for exploring exotic
quantum phenomena. Here, we report inelastic
neutron scattering investigations of the van der Waals antiferromagnet VBr3, which forms a honeycomb
lattice structure at room temperature and exhibits zigzag-type
magnetic order below 26.5 K. Our observations reveal distinctive low-energy
spin excitations arising from gamma, gamma', and M' points, each featuring a
spin gap of around 2.5 meV. The overall
spin excitation spectra can be effectively described by a
spin Hamiltonian incorporating substantial nearest-neighbor Kitaev and biquadratic interactions, along with Heisenberg interactions. Our findings not only establish VBr3 as a new Kitaev magnet but also suggest that ligand engineering may provide a promising strategy to modulate Kitaev interactions, offering new opportunities for designing Kitaev materials with tailored
quantum properties.
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All authors Zeyu Kao, Yimeng Gu, Yiqing Gu, Hao Zhang, Shiyi Zheng, Naoki Murai, Seiko Ohira-Kawamura, Jun Zhao
Statistical Mechanics · Cross-listed from hep-th
Entanglement negativity for a free scalar chiral current
Malen Arias, Marina Huerta, Andrei Rotaru et al. (+1 more)
We study the
entanglement negativity for the free, scalar
chiral current in two spacetime dimensions, which is a simple model violating the Haag duality in regions with nontrivial
topology. For the ground state of the system, both on the line and on the circle, we consider the setups given by two intervals, either adjacent or disjoint. We find analytic expressions for the moments of the partial transpose of the reduced density
matrix and the logarithmic negativity. In the limit of small separation distance, this expression yields the same subleading topological contribution occurring in the mutual information. In the limit of large separation distance between the two intervals, the exponential decay of the logarithmic negativity is obtained from its analytic expression. The analytic formulas are checked against exact numerical results from a bosonic
lattice model, finding a perfect agreement. We observe that, since the
chiral current generates the neutral subalgebra of the full
chiral Dirac
fermion theory, this analysis highlights how
symmetries produce nontrivial features in the
entanglement structure that are analogue to those ones already observed in the mutual information for regions with nontrivial
topology.
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All authors Malen Arias, Marina Huerta, Andrei Rotaru, Erik Tonni
Disordered Systems and Neural Networks
Spin-aligned butterfly spectral map in Non-Hermitian quasicrystals
Soumya Ranjan Padhi, Souvik Roy, Debashree Chowdhury et al. (+1 more)
The Non-Hermitian spinful Aubry-André-Harper (AAH) model in the presence of Rashba-type
spin-orbit coupling (RSOC) and a spatially varying textured
magnetic field is studied. Interestingly, our analysis produces a butterfly spectral map due to the non-trivial extent of localization of the states in the spectrum. This spectral map also exhibits an asymmetric
spin alignment with respect to the wings of the butterfly. Our analysis also suggests that the onset of such a spectral map is a combined effect of the non-hermiticity,
spin-orbit interaction, and the textured
magnetic field.
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All authors Soumya Ranjan Padhi, Souvik Roy, Debashree Chowdhury, Tapan Mishra
Mesoscale and Nanoscale Physics · Cross-listed from quant-ph
Signatures of Spin Coherence in Chiral Coupled Quantum Dots
Hanna T. Fridman, Rotem Malkinson, Amir Hen et al. (+3 more)
Chiral-induced
spin selectivity (CISS) enables
spin selectivity of charge carriers in
chiral molecular systems without
magnetic materials. While
spin selectivity has been widely investigated, its
quantum coherence has not yet been explored. Here, we investigate
spin-dependent photoluminescence (PL) dynamics in multilayer
quantum-dot (QD) assemblies coupled by
chiral linkers. Using circularly polarized excitation in the presence of an external
magnetic field, we observe a pronounced modulation of the PL lifetime that depends on the
magnetic field magnitude and geometry. The lifetime difference between left- and right-circularly polarized excitations exhibits a field-angle dependence, consistent with
spin precession driven by the transverse
magnetic-field component relative to the
chiral axis. A model incorporating coupled
spin precession and decay processes reproduces the experimental trends. These results establish
chiral QD assemblies as a room-temperature platform for probing
quantum coherent manifestations of the CISS effect, with implications for spintronic and
quantum technologies.
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All authors Hanna T. Fridman, Rotem Malkinson, Amir Hen, Shira Yochelis, Yossi Paltiel, Nir Bar-gill
Materials Science
Three-dimensional Moiré crystallography
Ilya Popov and Elena Besley
Moiré materials, typically confined to stacking atomically thin, two - dimensional (2D) layers such as
graphene or transition metal dichalcogenides, have transformed our understanding of strongly correlated and topological
quantum phenomena. The
lattice mismatch and relative twist angle between 2D layers have shown to result in Moiré patterns associated with widely tunable electronic properties, ranging from Mott and Chern
insulators to semi- and super-conductors. Extended to three-dimensional (3D) structures, Moiré materials unlock an entirely new crystallographic space defined by the elements of the 3D rotation group and translational
symmetry of the constituent
lattices. 3D Moiré
crystals exhibit fascinating novel properties, often not found in the individual components, yet the general construction principles of 3D Moiré
crystals remain largely unknown. Here we establish fundamental mathematical principles of 3D Moiré crystallography and propose a general method of 3D Moiré
crystal construction using Clifford
algebras over the field of rational numbers. We illustrate several examples of 3D Moiré structures representing realistic chemical frameworks and highlight their potential applications in condensed matter physics and solid-state chemistry.
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Materials Science
Goldene monolayer as a highly effective catalyst for polysulfide anchoring and conversion: A theoretical study
Nicolas F. Martins, José A. dos S. Laranjeira, Bill D. A. Huacarpuma et al. (+3 more)
We use first-principles density functional theory to investigate how lithium sulfide and polysulfide clusters (Li2S, Li2S2, Li2S4, Li2S6, Li2S8, and S8) bind to Goldene, a new two-dimensional gold allotrope. All Li-S species exhibit robust binding to Goldene. The adsorption energies range from -4.29 to -1.90 eV. S8 that is alone interacts much less strongly. Charge density difference and Bader analyses indicate that substantial charge is transferred to the substrate, with a maximum 0.92 e for Li-rich clusters. This transfer induces polarization at the interface and shifts the work function to 5.30-5.52 eV. Projected density-of-states calculations indicate that Au-d and S-p states strongly mix near the
Fermi level. This hybridization indicates that the electronic coupling is strong. Based on these results, the reaction free-energy profile for the stepwise conversion of S8 to Li2S on Goldene is thermodynamically favorable. The overall stabilization is -3.64 eV, and the rate-determining barrier for the Li2S2 -> Li2S step is 0.47 eV. This shows that Goldene is an effective surface for anchoring and mediating lithium polysulfide reactions.
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All authors Nicolas F. Martins, José A. dos S. Laranjeira, Bill D. A. Huacarpuma, Kleuton A. L. Lima, Luiz A. Ribeiro Jr, Julio R. Sambrano
Statistical Mechanics
Microscopic and hydrodynamic correlation in 1d hard rod gas
Indranil Mukherjee, Seema Chahal and Anupam Kundu
We compute mass density correlations of a one-dimensional gas of hard rods at both microscopic and macroscopic scales. We provide exact analytical calculations of the microscopic correlation. For the correlation at macroscopic scale, we utilize Ballistic Macroscopic Fluctuation Theory (BMFT) to derive an explicit expression for the correlations of a coarse-grained mass density, which reveals the emergence of long-range correlations on the Euler space-time scale. By performing a systematic coarse-graining of our exact microscopic results, we establish a micro-macro correspondence and demonstrate that the resulting macroscopic correlations agree precisely with the predictions of BMFT. This analytical verification provides a concrete validation of the underlying assumptions of hydrodynamic theory in the context of hard rod gas.
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Quantum Gases
Stability and mixed phases of three-component droplets in one dimension
I. A. Englezos, E. G. Charalampidis, P. Schmelcher et al. (+1 more)
We explore the ground state properties and excitation spectra of one-dimensional, three-component bosonic mixtures, where two majority components form a self-bound droplet coupled to a third, minority component. Within a self-consistent Lee-Huang-Yang framework, we identify distinct mixed self-bound droplet phases and characterize their phase transitions through variations of either the particle number of the majority components or the intercomponent coupling. The ensuing phases demonstrate that the minority component is untrapped, partially trapped, or fully trapped by the majority droplet species. These states are characterized by their binding energies captured by the chemical potentials and their low-amplitude excitation spectrum, including mode crossings at the particle-emission threshold. We further derive effective reduced models in the high-imbalance limit, which accurately reproduce the numerically computed ground states, while providing analytical insights into the role of
quantum fluctuations. Our results establish the stability and structure of mixed droplet phases provide experimentally relevant signatures for their identification.
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All authors I. A. Englezos, E. G. Charalampidis, P. Schmelcher, S. I. Mistakidis
Quantum Gases
Enhanced Microwave Sensing with Dissipative Continuous Time Crystals
Yunlong Xue, Zhengyang Bai and Yu-Qiang Ma
A dissipative time
crystal is an emergent phase in driven-dissipative
quantum many-body systems, characterized by sustained oscillations that break time-translation
symmetry spontaneously. Here, we explore nonequilibrium phase transitions in a dissipative Rydberg system driven by a microwave (MW) field and demonstrate their critical sensitivity to high-precision MW sensing. Distinct dynamical regimes are identified, including monostable, bistable, and oscillatory phases under mean-field coupling. Unlike single-particle detection–where the beating signal decays linearly with MW field strength–the time crystalline phase exhibits high sensitivity to MW perturbations, with rapid, discontinuous frequency switching near the monostable-oscillatory boundary. The abrupt transition is rooted in spontaneous
symmetry breaking in time and is fundamentally insensitive to the background noise. On this basis, a minimum detectable MW field strength on the order of 1nV/cm is achieved by leveraging this sensitivity. Our results establish a framework for controlling time crystalline phases with external fields and advance MW sensing through many-body effects.
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Soft Condensed Matter
Exploring structure-property relationship on a nanoscale for tailoring films of amphiphilic polymer co-networks
Kevin Hagmann, Carina Schneider, Stephanie Ihmann et al. (+2 more)
Amphiphilic
polymer co-networks (APCNs) provide a large toolbox for tuning coatings important for applications such as bio-interfaces. Therefore, we investigate the influence of network composition and environmental conditions on the structure and mechanical and adhesive properties of thin films composed of hydrophobic tetra-PCL and hydrophilic tetra-PEG
stars of varying sizes. State-of-the-art atomic force microscopy (AFM) techniques, including phase imaging, fast quantitative static indentation and dynamic indentation, provide insights into the structure-property-relationship on various length scales. PEG-rich networks exhibit amorphous morphologies with spherical nanodomains and elastic
moduli of a few MPa, while PCL-rich networks form semicrystalline cylindrical arrangements with
moduli up to several hundred MPa in water. Temperature-dependent measurements in water revealed a strong hysteresis of elastic
moduli while shifting the melting/crystallization transitions or preventing crystallization in PEG-rich networks. All networks displayed predominantly elastic behavior. Co-networks in non-selective solvent conditions are overall softer, less adhesive and structurally more homogeneous. These results establish a predictable correlation of network composition, physical and chemical environment, structure and properties, which makes them suitable for a rational design of amphiphilic systems for various applications.
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All authors Kevin Hagmann, Carina Schneider, Stephanie Ihmann, Frank Böhme, Regine von Klitzing
Materials Science
Exploring the Potential of Two-dimensional Borospherene for Toxic Gas Sensing and Capture: A DFT Study
Nicolas F. Martins, José A. dos S. Laranjeira, Kleuton A. L. Lima et al. (+2 more)
Two-dimensional (2D) boron-based materials have gained increasing interest due to their exceptional physicochemical properties and potential technological applications. In this way, borospherenes, a 2D Boron-based fullerene-like
lattice (2D-B40), are explored due to their potential for capturing and detecting toxic gases, such as CO, NO, NH3, and SO2. Therefore, density functional theory simulations were carried out to explore the adsorption energy and the distinct interaction regimes, where CO exhibits weak physisorption (-0.16 eV), while NO (-2.24 eV), NH3 (-1.47 eV), and SO2 (-1.51 eV) undergo strong chemisorption. Bader charge analysis reveals significant electron donation from 2D-B40 to NO and electron acceptance from SO2. These interactions cause measurable shifts in work function, with SO2 producing the most significant modulation (14.6%). Remarkably, ab initio molecular dynamics simulations (AIMD) reveal spontaneous SO2 decomposition at room temperature, indicating dual functionality for both sensing and environmental remediation. Compared to other boron-based materials, such as chi3-borophene, beta12-borophene, and B40 fullerene, 2D-B40 exhibits superior gas affinity, positioning it as a versatile platform for the detection and capture of toxic gases.
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All authors Nicolas F. Martins, José A. dos S. Laranjeira, Kleuton A. L. Lima, Luiz A. Ribeiro Jr, Julio R. Sambrano
Mesoscale and Nanoscale Physics · Cross-listed from physics.optics
Long-lived state of a helium-like magnesium donor in silicon
R.Kh. Zhukavin, D.A. Postnov, P.A. Bushuikin et al. (+10 more)
The relaxation of ortho states of a helium-like Mg donor in silicon is investigated by measuring the modulation of background radiation transmission through
impurity centers under pulsed photoexcitation. Long-lived states of the
spin-triplet 1s(3T2) group with a lifetime of about 20 ms are observed. The temperature dependence indicates that the relaxation is governed by the Orbach mechanism with an activation energy ~13 meV, which is close to the exchange splitting energy of the excited 1s states of the Mg donor.
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All authors R.Kh. Zhukavin, D.A. Postnov, P.A. Bushuikin, K.E. Kudryavtsev, K.A. Kovalevsky, V.V. Tsyplenkov, N.A. Bekin, A.N. Lodygin, L.M. Portsel, V.B. Shuman, Yu.A. Astrov, N.V. Abrosimov, V.N. Shastin
Statistical Mechanics
Short-time statistics of extinction and blowup in reaction kinetics
Rotem Degany, Michael Assaf and Baruch Meerson
We study the statistics of extinction and blowup times in well-mixed systems of stochastically reacting particles. We focus on the short-time tail, $T \to 0$, of the extinction- or blowup-time distribution $\mathcal{P}_m(T)$, where $m$ is the number of particles at $t=0$. This tail often exhibits an essential singularity at $T=0$, and we show that the singularity is captured by a time-dependent WKB (Wentzel-Kramers-Brillouin) approximation applied directly to the master equation. This approximation, however, leaves undetermined a large pre-exponential factor. We show how to calculate this factor by applying a leading- and a subleading-order WKB approximation to the Laplace-transformed backward master equation. Accurate asymptotic results can be obtained when this WKB solution can be matched to another approximate solution (the “inner" solution), valid for not too large $m$. We demonstrate and verify this method on three examples of reactions which are also solvable without approximations.
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