CMP Journal 2025-01-06
Statistics
Physical Review Letters: 14
arXiv: 43
Physical Review Letters
Universal Upper Bound on Ergotropy and No-Go Theorem by the Eigenstate Thermalization Hypothesis
Research article | Eigenstate thermalization | 2025-01-06 05:00 EST
Akihiro Hokkyo and Masahito Ueda
We show that the maximum extractable work (ergotropy) from a quantum many-body system is constrained by ''local athermality'' of an initial state and ''local entropy decrease'' brought about by quantum operations. The obtained universal upper bound on ergotropy implies that the eigenstate thermalization hypothesis prohibits work extraction from energy eigenstates by means of finite-time unitary operations. This no-go property implies that Planck's principle, a form of the second law of thermodynamics, holds even for pure quantum states. Our result bridges two independently studied concepts of quantum thermodynamics, the second law and thermalization, via ''intrasystem'' correlations in many-body systems as a resource for work extraction.
Phys. Rev. Lett. 134, 010406 (2025)
Eigenstate thermalization, Quantum statistical mechanics, Quantum thermodynamics, Thermodynamics, Quantum many-body systems
Quantum Zeno Engines and Heat Pumps
Research article | Quantum Zeno dynamics | 2025-01-06 05:00 EST
Giovanni Barontini
We study the implementation of quantum engines and quantum heat pumps where the quantum adiabatic transformations are replaced by quantum Zeno strokes. During these strokes, frequent measurements are selectively performed on the external state of the system avoiding transition between different levels. This effectively delivers almost ideal isentropic transformations. We concentrate on the characterization of the performance of a quantum Zeno heat pump implemented with a quantum harmonic oscillator, showing that optimal performance can be achieved faster than with shortcut-to-adiabaticity techniques.
Phys. Rev. Lett. 134, 010407 (2025)
Quantum Zeno dynamics, Quantum harmonic oscillator, Quantum measurements, Quantum nondemolition measurement, Quantum thermodynamics, Quantum heat engines & refrigerators
Programmable Quantum Simulations on a Trapped-Ion Quantum Computer with a Global Drive
Research article | Quantum gates | 2025-01-06 05:00 EST
Yotam Shapira, Jovan Markov, Nitzan Akerman, Ady Stern, and Roee Ozeri
Simulation of quantum systems is notoriously challenging for classical computers, while quantum hardware is naturally well-suited for this task. However, the imperfections of contemporary quantum systems pose a considerable challenge in carrying out accurate simulations over long evolution times. Here, we experimentally demonstrate a method for quantum simulations on a small-scale trapped-ion--based quantum simulator. Our method enables quantum simulations of programmable spin-Hamiltonians, using only simple global fields, driving all qubits homogeneously and simultaneously. We measure the evolution of a quantum Ising ring and accurately reconstruct the Hamiltonian parameters, showcasing an accurate and high-fidelity simulation. Our method enables a significant reduction in the required control and depth of quantum simulations, thus generating longer evolution times with higher accuracy.
Phys. Rev. Lett. 134, 010602 (2025)
Quantum gates, Quantum information with trapped ions, Quantum simulation, Trapped ions
Compression of Quantum Shallow-Circuit States
Research article | Quantum circuits | 2025-01-06 05:00 EST
Yuxiang Yang
Shallow quantum circuits feature not only computational advantages over their classical counterparts but also cutting-edge applications. Storing quantum information generated by shallow circuits is a fundamental question of both theoretical and practical importance that remained largely unexplored. In this Letter, we show that \(N\) copies of an unknown \(n\)-qubit state generated by a fixed-depth circuit can be compressed into a hybrid memory of \(O(n{\mathrm{log}}_{2}N)\) (qu)bits, which achieves the optimal scaling of memory cost. Our work shows that the computational complexity of resources can significantly impact the rate of quantum information processing, offering a unique and unified view of quantum Shannon theory and quantum computing.
Phys. Rev. Lett. 134, 010603 (2025)
Quantum circuits, Quantum communication, protocols & technology, Quantum information processing, Quantum information theory
Model-Independent Tests of the Hadronic Vacuum Polarization Contribution to the Muon \(g- 2\)
Research article | Magnetic moment | 2025-01-06 05:00 EST
Luca Di Luzio, Alexander Keshavarzi, Antonio Masiero, and Paride Paradisi
The hadronic vacuum polarization (HVP) contributions to the muon \(g- 2\) are the crucial quantity to resolve whether new physics is present or not in the comparison between the standard model (SM) prediction and experimental measurements at Fermilab. They are commonly and historically determined via dispersion relations using a vast catalogue of experimentally measured, low-energy \({e}^{+}{e}^{- }\rightarrow \text{hadrons}\) cross section data as input. These dispersive estimates result in a SM prediction that exhibits a muon \(g- 2\) discrepancy of more than $5$ when compared to experiment. However, recent lattice QCD evaluations of the HVP and a new hadronic cross section measurement from the CMD-3 experiment favor a no-new-physics scenario and, therefore, exhibit a common tension with the previous \({e}^{+}{e}^{- }\rightarrow \text{hadrons}\) data. This study explores the current and future implications of these two scenarios on other observables that are also sensitive to the HVP contributions in the hope that they may provide independent tests of the current tensions observed in the muon \(g- 2\).
Phys. Rev. Lett. 134, 011902 (2025)
Magnetic moment, Phenomenology, Quantum chromodynamics, Strong interaction
QCD Constraints on Isospin-Dense Matter and the Nuclear Equation of State
Research article | Equations of state of nuclear matter | 2025-01-06 05:00 EST
Ryan Abbott, William Detmold, Marc Illa, Assumpta Parreño, Robert J. Perry, Fernando Romero-López, Phiala E. Shanahan, and Michael L. Wagman (NPLQCD Collaboration)
Simulations of neutron stars provide new bounds on their properties, such as their internal pressure and their maximum mass.
Phys. Rev. Lett. 134, 011903 (2025)
Equations of state of nuclear matter, Lattice QCD, Nuclear matter in neutron stars
Chiral Interaction Induced Near-Perfect Photon Blockade
Research article | Photon statistics | 2025-01-06 05:00 EST
Zhi-Guang Lu, Ying Wu, and Xin-You Lü
Based on the scattering matrix method, we theoretically demonstrate that the chiral interaction can induce the almost perfect photon blockade (PB) in the waveguide-cavity quantum electrodynamics system. The mechanism relies on the multiphoton path's interference within the waveguide, which is clearly shown by the analytic parameter regime for \({g}^{(2)}(0)\approx 0\). When \(N\) cavities are introduced into the system, there are \(N\) optimal parameter points accordingly for the almost perfect PB, where the required lowest chirality decreases exponentially with increasing \(N\), and these optimal points are robust against disorder in the system's frequencies. Under resonant driving and fixed chirality conditions, the output light depends solely on the parity of \(N\) (\(N\ge 2\)), with a coherent state emerging for even numbers of cavities and a single-photon state for odd numbers. Our Letter offers an alternative route for achieving almost perfect PB effects with high single-photon transmission by employing the chirality of system, with potential application in the on-chip single-photon source with integrability.
Phys. Rev. Lett. 134, 013602 (2025)
Photon statistics, Photonic crystals, Quantum optics, Scattering theory, Single photon sources
Phase-Locking Parametric Instability Coupling Longitudinal and Transverse Waves on Rivulets in a Hele-Shaw Cell
Research article | Contact line dynamics | 2025-01-06 05:00 EST
Grégoire Le Lay and Adrian Daerr
We report an instability exhibited by a fluid system when coupling two distinct types of waves, both linearly damped. While none of them is unstable on its own, they amplify one another, resulting in a previously unreported convective instability. An external excitation is used to induce a parametric cross-coupling between longitudinal and transverse deformations of a liquid bridge between two vertical glass plates. Coherent amplification results in waves satisfying a synchronization condition, which selects a precise wavelength. We derive a model for this instability using depth-averaged Navier-Stokes equations, showing the physical origin of the coamplification, and confirm its relevance experimentally. Our findings open new perspectives in the study of parametrically controlled pattern formation, and invites the search for analogous parametric cross-coupling instabilities in other systems exhibiting distinct wave types, from plasma to elastic media.
Phys. Rev. Lett. 134, 014001 (2025)
Contact line dynamics, Flow instability, Hele-shaw flows, Instability of free-surface flows, Interfacial flows, Liquid bridges, Nonlinear dynamics in fluids, Thin fluid films, Hele-Shaw cell, Navier-Stokes equation
Unconventional Scalings of Quantum Entropies in Long-Range Heisenberg Chains
Research article | Critical phenomena | 2025-01-06 05:00 EST
Jiarui Zhao, Nicolas Laflorencie, and Zi Yang Meng
In this work, building on state-of-the-art quantum Monte Carlo simulations, we perform systematic finite-size scaling of both entanglement and participation entropies for long-range Heisenberg chain with unfrustrated power-law decaying interactions. We find distinctive scaling behaviors for both quantum entropies in the various regimes explored by tuning the decay exponent $$, thus capturing nontrivial features through logarithmic terms, beyond the case of linear Nambu-Goldstone modes. Our systematic analysis reveals that the quantum entanglement information, hidden in the scaling of the two studied entropies, can be obtained to the same level of order parameters and other usual finite-size observables of quantum many-body lattice models. The analysis and results obtained here can readily apply to more quantum criticalities in 1D and 2D systems.
Phys. Rev. Lett. 134, 016707 (2025)
Critical phenomena, Entanglement entropy, Ferromagnetism, Phase diagrams, Heisenberg model
Observation of Universal Topological Magnetoelectric Switching in Multiferroic \({\mathrm{GdMn}}_{2}{\mathrm{O}}_{5}\)
Research article | Electric polarization | 2025-01-06 05:00 EST
Haowen Wang, Fan Wang, Ming Yang, Yuting Chang, Mengyi Shi, Liang Li, Jun-Ming Liu, Junfeng Wang, Shuai Dong, and Chengliang Lu
Topological magnetoelectricity was recently revealed as an emergent topic, which opens a unique route to precisely control magnetoelectric functionality. Here we report the synchronous magnetic-electric-cycle operation of topological magnetoelectric switching in \({\mathrm{GdMn}}_{2}{\mathrm{O}}_{5}\). Compared with pure magnetic-cycle operation, this topological winding can be accessed in a much broader parameter space, i.e., orientation of the magnetic field is not limited to the magic angle and the effect can persist up to the Curie temperature. The fine-tuning of the free energy landscape is responsible for this topological behavior.
Phys. Rev. Lett. 134, 016708 (2025)
Electric polarization, Single crystal materials, Magnetization measurements
Geometry of Optimal Control in Chemical Reaction Networks in the Adiabatic Limit
Research article | Classical statistical mechanics | 2025-01-06 05:00 EST
Yikuan Zhang, Qi Ouyang, and Yuhai Tu
Although optimal control (OC) has been studied in stochastic thermodynamics for systems with continuous state variables, less is known in systems with discrete state variables, such as chemical reaction networks (CRNs). Here, we develop a general theoretical framework to study OC of CRNs for changing the system from an initial distribution of states to a final distribution with minimum dissipation. We derive a ''Kirchhoff's law'' for the probability current in the adiabatic limit, from which the optimal kinetic rates are determined analytically for any given probability trajectory allowed by local rate constraints. By using the optimal rates, we show that the total dissipation is determined by a \({L}_{2}\)-distance measure in the probability space and derive an analytical expression for the metric tensor that depends on the probability distribution, network topology, and capacity of each link. Minimizing the total dissipation leads to the geodesic trajectory in the probability space and the corresponding OC protocol is determined by the Kirchhoff's law. To demonstrate our general approach, we use it to find a lower bound for the minimum dissipation that is tighter than existing bounds obtained with only global constraints in the adiabatic limit. We also apply it to simple networks, e.g., fully connected three-state CRNs with different local constraints and show that indirect pathway and nonfunctional transient state can play a crucial role in switching between different probability distributions efficiently. Future directions in studying OC in CRNs by using our general framework are discussed.
Phys. Rev. Lett. 134, 018001 (2025)
Classical statistical mechanics, Network flow optimization, Nonequilibrium & irreversible thermodynamics, Nonequilibrium statistical mechanics, Optimization problems, Stochastic thermodynamics
Encoding Fast and Fault-Tolerant Memories in Bulk and Nanoscale Amorphous Solids
Research article | Amorphous materials | 2025-01-06 05:00 EST
Monoj Adhikari, Rishabh Sharma, and Smarajit Karmakar
We investigate the memory effects in cyclically deformed amorphous solids through computer simulations. Applying oscillatory shear deformations in all orthogonal directions during encoding creates fault-tolerant memories that are agnostic to the reading direction. Our extensive system size analysis shows that memory encoding is faster in small systems and becomes exceedingly challenging as systems approach the thermodynamic limit. To capitalize on the quickness of memory encoding in small system sizes, it is important to demonstrate that memory can be encoded in nanoscale objects, where open surfaces play a crucial role. We achieve this by going from 3D bulk to pseudo-1D nanorods. Using tension-compression cycles on these nanorods, we show that memory encoding and reading are also possible in the presence of free surfaces.
Phys. Rev. Lett. 134, 018202 (2025)
Amorphous materials, Disordered systems, Glasses, Molecular dynamics
Traveling Strings of Active Dipolar Colloids
Research article | Collective behavior | 2025-01-06 05:00 EST
Xichen Chao, Katherine Skipper, C. Patrick Royall, Silke Henkes, and Tanniemola B. Liverpool
We study an intriguing new type of self-assembled active colloidal polymer system in 3D. It is obtained from a suspension of Janus particles in an electric field that induces parallel dipoles in the particles as well as self-propulsion in the plane perpendicular to the field. At low volume fractions, in experiment, the particles self-assemble into 3D columns that are self-propelled in 2D. Explicit numerical simulations combining dipolar interactions and active self-propulsion find an activity dependent transition to a string phase by increasing dipole strength. We classify the collective dynamics of strings as a function of rotational and translational diffusion. Using an anisotropic version of the Rouse model of polymers with active driving, we analytically compute the strings' collective dynamics and center of mass motion, which matches simulations and is consistent with experimental data. We also discover long range correlations of the fluctuations along the string contour that grow with the active persistence time, a purely active effect that disappears in the thermal limit.
Phys. Rev. Lett. 134, 018302 (2025)
Collective behavior, Living matter & active matter, Nonequilibrium statistical mechanics, Polymer conformation & topology
Emergent Rate-Based Dynamics in Duplicate-Free Populations of Spiking Neurons
Research article | Biological neural networks | 2025-01-06 05:00 EST
Valentin Schmutz, Johanni Brea, and Wulfram Gerstner
Can spiking neural networks (SNNs) approximate the dynamics of recurrent neural networks? Arguments in classical mean-field theory based on laws of large numbers provide a positive answer when each neuron in the network has many ''duplicates'', i.e., other neurons with almost perfectly correlated inputs. Using a disordered network model that guarantees the absence of duplicates, we show that duplicate-free SNNs can converge to recurrent neural networks, thanks to the concentration of measure phenomenon. This result reveals a general mechanism underlying the emergence of rate-based dynamics in large SNNs.
Phys. Rev. Lett. 134, 018401 (2025)
Biological neural networks, Spiking neurons, Disordered systems, Mean field theory, Spiking neuron models
arXiv
Hydride superconductivity: here to stay, or to lead astray and soon go away?
New Submission | Superconductivity (cond-mat.supr-con) | 2025-01-06 00:00 EST
In a recent Comment (arXiv:2411.10522, Nat Rev Phys 7, 2 (2025)), fifteen prominent leaders in the field of condensed matter physics declare that hydride superconductivity is real and urge funding agencies to continue to support the field. I question the validity and constructiveness of their argument.
Superconductivity (cond-mat.supr-con)
Phase-Field Modeling of Fracture under Compression and Confinement in Anisotropic Geomaterials
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Maryam Hakimzadeh, Carlos Mora-Corral, Noel Walkington, Giuseppe Buscarnera, Kaushik Dayal
Strongly anisotropic geomaterials undergo fracture under compressive loading. This paper applies a phase-field fracture model to study this fracture process. While phase-field fracture models have several advantages, they provide unphysical predictions when the stress state is complex and includes compression that can cause crack faces to contact. Building on a phase-field model that accounts for compressive traction across the crack face, this paper extends the model to anisotropic fracture. The key features include: (1) a homogenized anisotropic elastic response and strongly-anisotropic model for the work to fracture; (2) an effective damage response that accounts consistently for compressive traction across the crack face, that is derived from the anisotropic elastic response; (3) a regularized crack normal field that overcomes the shortcomings of the isotropic setting, and enables the correct crack response, both across and transverse to the crack face. To test the model, we first compare the predictions to phase-field fracture evolution calculations in a fully-resolved layered specimen with spatial inhomogeneity, and show that it captures the overall patterns of crack growth. We then apply the model to previously-reported experimental observations of fracture evolution in laboratory specimens of shales under compression with confinement, and find that it predicts well the observed crack patterns in a broad range of loading conditions. We further apply the model to predict the growth of wing cracks under compression and confinement. The effective crack response model enables us to treat the initial crack simply as a non-singular damaged zone within the computational domain, thereby allowing for easy and general computations.
Materials Science (cond-mat.mtrl-sci), Analysis of PDEs (math.AP)
To appear in International Journal for Numerical and Analytical Methods in Geomechanics
Monitorization of the H-O Bond Flexibility
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Unlike conventional thought, the H-O bond is flexible, instead, and sensitive to perturbation. This exercise empowers the electron and phonon spectroscopies with the Tight-binding approach, enabling a referential database to synchronically quantize the relaxation and flexibility of these identities for substances involving the H-O bond during phonon spectroscopy.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph)
Cavity Quantum Hall Hydrodynamics
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
Gabriel Cardoso, Liu Yang, Thors Hans Hansson, Qing-Dong Jiang
Motivated by recent experiments, we study the coupling of quantum Hall (QH) hydrodynamics to quantum electrodynamics (QED) within a resonance cavity. In agreement with experimental observations, we find that the Hall conductivity remains unchanged. However, the coupling to the cavity induces a second-order quantum reactance effect, contributing distinctly to the longitudinal AC conductivity. This effect arises from the exchange of energy between the QH fluid and cavity photons. Beyond the topological response, we show that the cavity couples to collective excitations, resulting in a shift of the Kohn mode frequency. Our methods are broadly applicable to both integral and fractional QH liquids, and our results offer a universal perspective on the protection of topological properties against long-range interactions induced by electromagnetic cavity modes.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Other Condensed Matter (cond-mat.other), Strongly Correlated Electrons (cond-mat.str-el)
6+4 pages, 4 figures
C\(_{60}\) building blocks with tuneable structures for tailored functionalities
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
We show that C\(_{60}\) fullerene molecules can serve as promising building blocks in the construction of versatile crystal structures with unique symmetries using first-principles calculations. These phases include quasi-2D layered structures and 3D van der Waals crystals where the molecules adopt varied orientations. The interplay of molecular arrangement and lattice symmetry results in a variety of tuneable crystal structures with distinct properties. Specifically, the electronic structures of these phases vary significantly, offering potential for fine-tuning the band gap for electronics and optoelectronics. Additionally, the optical properties of these materials are strongly influenced by their crystalline symmetry and molecular alignment, providing avenues for tailoring optical responses for photonics. Our findings highlight the potential of fullerene-based building blocks in the rational design of functional materials.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Materials Science (cond-mat.mtrl-sci), Applied Physics (physics.app-ph), Atomic and Molecular Clusters (physics.atm-clus), Chemical Physics (physics.chem-ph)
6 pages, 4 figures
Dissipation-enhanced non-reciprocal superconductivity: application to multi-valley superconductors
New Submission | Superconductivity (cond-mat.supr-con) | 2025-01-06 00:00 EST
Sayan Banerjee, Mathias S. Scheurer
We here propose and study theoretically a non-equilibrium mechanism for the superconducting diode effect, which applies specifically to the case where time-reversal-symmetry -- a prerequisite for the diode effect -- is spontaneously broken by the superconducting electrons themselves. We employ a generalized time-dependent Ginzburg-Landau formalism to capture dissipation effects in the non-equilibrium current-carrying state via phase slips and show that the coupling of the resistive current to the symmetry-breaking order is enough to induce a diode effect. Depending on parameters, the critical current asymmetry can be sizeable, asymptotically reaching a perfect diode efficiency; the competition of symmetry-breaking order, superconducting and resistive currents gives rise to rich physics, such as current-stabilized, non-equilibrium superconducting correlations. Although our mechanism is more general, the findings are particularly relevant to twisted trilayer and rhombohedral tetralayer graphene, where the symmetry-breaking order parameter refers to the imbalance of the two valleys of the systems.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
Out-of-equilibrium dynamical properties of Bose-Einstein condensates in a ramped up weak disorder
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-01-06 00:00 EST
Rodrigo P. A. Lima, Milan Radonjić, Axel Pelster
We theoretically study how the superfluid and condensate deformation of a weakly interacting ultracold Bose gas evolve during the ramp-up of an external weak disorder potential. Both resulting deformations turn out to consist of two distinct contributions, namely a reversible equilibrium one, already predicted by Huang and Meng in 1992, and a nonequilibrium dynamical one, whose magnitude depends on the details of the ramping protocol. For the specific case of the exponential ramp-up protocol, we are able to derive analytical time-dependent expressions for the above quantities. After a sufficiently long time, a steady state emerges that is generically out of equilibrium. We take the first step in investigating its properties by studying its relaxation dynamics. In addition, we analyze the two-time correlation function and elucidate its relation to the equilibrium and the dynamical part of the condensate deformation.
Quantum Gases (cond-mat.quant-gas)
Field-induced spin dynamics in i-MAX Tb compound
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-01-06 00:00 EST
Dror Yahav, Daniel Potashnikov, Asaf Pesach, El'ad N. Caspi, Quanzheng Tao, Johanna Ros'en, Moshe Schechter, Ariel Maniv, Eran Maniv
We report a comprehensive study of spin dynamics in the (Mo2/3Tb1/3)2AlC i-MAX compound using ac susceptibility measurements across a range of magnetic fields. Unique behaviors were observed, including spin dynamics in the kHz range between mu_0 H~0.2T-6T, indicating a non-trivial superparamagnetic state, suggesting that the compound acts as a transitional system within the i-MAX family, bridging stable spin-dynamic materials and fluctuation-dominated ones. Field- and frequency-dependent magnetic phase transitions, coupled with relaxation behaviors, reveal complex interactions between spin density waves and superparamagnetic components. These findings, corroborated by uSR studies, deepen our understanding of magnetic phase diagrams and field-induced phenomena in i-MAX systems, laying the groundwork for further exploration of their unique properties and applications.
Strongly Correlated Electrons (cond-mat.str-el)
7 pages, 5 figures
Architected Dual-Network Solvent-free Adhesives for Stretchable Fabrics
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Gabriela Moreira Lana, Cornelia Meissner, Siddhant Iyer, Xin Hu, Perin Jhaveri, Skylar Tibbits, Alfred J. Crosby
Natural systems, such as tendons and spider silk, demonstrate how the combination of strength and stretchability can be effectively achieved by integrating stiff and flexible network structures. Inspired by these systems, we developed a novel, solvent-free dual-network adhesive based on a self-assembling ABA triblock copolymer, poly(methyl methacrylate)-poly(n-butyl acrylate)-poly(methyl methacrylate) (PMMA-b-PnBA-b-PMMA), designed for applications requiring both high strength and stretchability. The triblock copolymer forms a physically crosslinked network through microdomains of PMMA end-blocks that provide structural integrity, while the PnBA mid-block forms a soft, stretchable matrix. To further enhance mechanical performance, a second poly(n-butyl acrylate) (PnBA) network is polymerized in situ, locking the PMMA microdomains in place and creating a load-bearing system. By varying the crosslinking density of the secondary network, we tailor the adhesive's mechanical properties (Young's modulus: 0.17 - 1.18 MPa) to suit different substrates, creating a mechanically transparent seam. The resulting dual-network system combines different strategies to achieve high strength and stretchability, with adhesive performance comparable to industrial methods such as sewing, particularly in bonding neoprene fabric composites and sealing the joints. Our solvent-free approach also eliminates the need for lengthy solvent evaporation steps, offering an eco-friendly and more efficient alternative for flexible adhesive applications in fields such as soft robotics, flexible electronics, and sports apparel.
Materials Science (cond-mat.mtrl-sci), Soft Condensed Matter (cond-mat.soft)
28 pages, 5 figures, supplemental included at the end
Magnetoconductivity and quantum oscillations in intercalated graphite CaC\(_6\) with the Fermi surface reconstructed by the uniaxial charge density wave
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
Petra Grozić, Anatoly M. Kadigrobov, Zoran Rukelj, Ivan Kupčić, Danko Radić
We report a magnetoconductivity tensor \(\sigma\) for the intercalated graphite CaC\(_6\), in the ground state of the uniaxial charge density wave (CDW), under conditions of coherent magnetic breakdown due to strong external magnetic field \(B\) perpendicular to the conducting plane. The uniaxial charge density wave reconstructs initially closed Fermi surface into an open one, accompanied with formation of a pseudo-gap in the electron density of states around the Fermi energy. The magnetoconductivity tensor is calculated within the quantum density matrix and semiclassical magnetic breakdown approach focused on modification of the main, so-called classical contribution to magnetoconductivity by magnetic breakdown, neglecting the higher order corrections. In the presence of magnetic breakdown, in spite of open Fermi surface configuration, all classical magnetoconductivity components, the one along the CDW apex \(\sigma_{xx} \sim 1/B^2\), perpendicular to the CDW apex \(\sigma_{yy} \sim const\), as well as the Hall conductivity \(\sigma_{xy} \sim 1/B\), undergo strong quantum oscillations vs. inverse magnetic field. Those oscillations do not appear as a mere additive correction, but rather alter the classical result becoming an inherent part of it, turning it to essentially non-classical.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
11 pages, 5 figures
Magnetic properties of Ge, Re and Cr substituted Fe\(_5\)SiB\(_2\)
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
M. Casadei, M.M. Isah, R. Cabassi, G. Trevisi, S. Fabbrici, M. Belli, C. de Julián Fernández, G. Allodi, V. Fournée, S. Sanna, F. Albertini
One of the possible approaches to decrease the demand for critical elements such as rare earths is to develop new sustainable magnets. Iron-based materials are suitable for gap magnets applications since iron is the most abundant ferromagnetic element on Earth. Fe\(_5\)SiB\(_2\) is a candidate as gap magnet thanks to its high Curie temperature (T\(_{\text{C}} \sim\) 800 K) and saturation magnetization (M\(_{\text{S}}\sim\) 140 Am\(^2\)kg\(^{-1}\)). However its anisotropy field is too low for applications (H\(_{\text{A}} \sim\) 0.8 T). In order to increase the anisotropy value, we synthesized a series of Ge, Re and Cr substituted Fe\(_5\)SiB\(_2\) samples and studied their magnetic properties. They all crystallize in the Cr\(_5\)B\(_3\)-type tetragonal structure with the \(I4/mcm\) space group. Curie temperature (T\(_{\text{C}}\) = 803 K) and saturation magnetization (M\(_{\text{S}}\) = 138 Am\(^2\)kg\(^{-1}\)) are slightly decreased by elemental substitution with Re having the largest effect. Despite being reduced, T\(_{\text{C}}\) and M\(_{\text{S}}\) still maintain significant values (T\(_{\text{C}}>\) 750 K and M\(_{\text{S}}\) = 118 Am\(^2\)kg\(^{-1}\)). The room temperature anisotropy field has been measured by Singular Point Detection (SPD) and increases by about 15% upon Re substitution, reaching 0.92 T for Fe\(_{4.75}\)Re\(_{0.25}\)SiB\(_2\). We have also used Nuclear Magnetic Resonance and SPD measurements to study the spin reorientation transition which takes place at 172 K and we have found that it is partially suppressed by substitution of Ge from 172 K to 140 K and completely suppressed upon Cr and Re substitution.
Materials Science (cond-mat.mtrl-sci)
The paper consists of a main section and supplementary materials. The main section includes 15 pages, featuring 6 figures and 2 tables. The supplementary materials, appended at the end of the main section, span 4 pages and contain 6 figures
Generation of spin wave packets by reconfigurable magnonic heterojunctions
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
A. Roxburgh, P. Micaletti, F. Montoncello, E. Iacocca
Nano-magnonic crystals are magnetic waveguides whose magnetic parameters are modulated at the nanoscale. The super-lattice structure enables a band structure and magnonic band-gaps. Here, we numerically investigate the field tunability of such a magnonic band-gap. By subjecting different parts of the nano-magnonic crystal to a field, we realize a magnonic heterojunction. A numerical demonstration of an active modification of the band structure leads to magnonic amplitude modulation in the linear regime and magnonic frequency combs in the nonlinear regime. Our results offer further opportunities for nano-magnonic crystals and incite their experimental realization.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Striped Spin Density Wave in a Graphene/Black Phosphorous Heterostructure
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-01-06 00:00 EST
Dolev Haddad, H.A. Fertig, Efrat Shimshoni
A bilayer formed by stacking two distinct materials creates a moiré lattice, which can serve as a platform for novel electronic phases. In this work we study a unique example of such a system: the graphene-black phosphorus heterostructure (G/BP), which has been suggested to have an intricate band structure. Most notably, the valence band hosts a quasi-one-dimensional region in the Brillouin zone of high density of states, suggesting that various many-body electronic phases are likely to emerge. We derive an effective tight-binding model that reproduces this band structure, and explore the emergent broken-symmetry phases when interactions are introduced. Employing a mean-field analysis, we find that the favored ground-state exhibits a striped spin density wave (SDW) order, characterized by either one of two-fold degenerate wave-vectors that are tunable by gating. Further exploring the phase-diagram controlled by gate voltage and the interaction strength, we find that the SDW-ordered state undergoes a metal to insulator transition via an intermediate metallic phase which supports striped SDW correlations. Possible experimental signatures are discussed, in particular a highly anisotropic dispersion of the collective excitations which should be manifested in electric and thermal transport.
Strongly Correlated Electrons (cond-mat.str-el), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
15 pages, 14 figures
Anomalous skew scattering of plasma waves in a Dirac electron fluid
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
Cooper Finnigan, Dmitry Efimkin
The Berry phase-related nontrivial electronic band geometries can significantly influence bulk and edge plasma waves, or plasmons, resulting in their non-reciprocal propagation and opening new opportunities for plasmonics. In the present work, we extend the hydrodynamic framework to describe the scattering of plasma waves in a Dirac electron fluid off a circular region with an induced nonzero anomalous Hall response, i.e. a Berry flux target. We demonstrate that the scattering has a giant asymmetry or skewness and exhibits a series of resonances. The latter appears due to a chiral non-topological trapped mode circulating the target. We discuss possible experimental realizations, including the surface of a topological insulator film and graphene irradiated by the circularly polarized beam.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
10 pages, 5 figures
Weyl semimetallic, N'eel, spiral, and vortex states in the Rashba-Hubbard model
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-01-06 00:00 EST
Sebastião dos Anjos Sousa-Júnior, Rubem Mondaini
We investigate the evolution of magnetic phases in the Hubbard model under strong Rashba spin-orbit coupling on a square lattice. By using Lanczos exact diagonalization and determinant quantum Monte Carlo (DQMC) simulations, we explore the emergence of various magnetic alignments as the ratio between the regular hopping amplitude, \(t\), and the Rashba hopping term, \(t_R\), is varied over a broad range of Hubbard interaction strengths, \(U\). In the limit \(t_R \rightarrow 0\), the system exhibits Néel antiferromagnetic order, while when \(t \sim t_R\), a spiral magnetic phase emerges due to the induced anisotropic Dzyaloshinskii-Moriya interaction. For \(t_R > t\), we identify the onset of a spin vortex phase. At the extreme limit \(t = 0\)($t_R $), we perform finite-size scaling analysis in the Weyl semimetal regime to pinpoint the quantum critical point associated with the spin vortex phase, employing sign-free quantum Monte Carlo simulations - the extracted critical exponents are consistent with a Gross-Neveu-type quantum phase transition.
Strongly Correlated Electrons (cond-mat.str-el)
Unveiling potential candidates for rare-earth-free permanent magnet and magnetocaloric effect applications: a high throughput screening in Fe-N alloys
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Qiang Gao, Ergen Bao, Ijaz Shahid, Hui Ma, Xing-Qiu Chen
Based on high-throughput density functional theory calculations, we have found 49 ferromag-netic cases in FexN1-x (0<x<1) compounds, focusing especially on permanent magnet and giant magnetocaloric effect applications. It is found that 15 compounds are potential permanent mag-nets with a magneto-crystalline anisotropy energy more than 1 MJ/m3, filling in the gap of appli-cation spectrum between high-performance and widely used permanents. Among the potential permanent magnets, Fe2N can be classified as a hard magnet while the other 14 compounds can be classified as semi-hard magnets. According to the calculations of magnetic deformation proxy, 40 compounds are identified as potential giant magnetocaloric effect candidates. We suspect that Fe-N compounds provide fine opportunities for applications in both rare-earth free permanent magnets and magnetocaloric effect.
Materials Science (cond-mat.mtrl-sci)
3 figures, 18 pages
Visualization of intervalley coherent phase in PtSe2/HOPG heterojunction
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
Kai Fan, Bohao Li, Wen-Xuan Qiu, Ting-Fei Guo, Jian-Wang Zhou, Tao Xie, Wen-Hao Zhang, Chao-Fei Liu, Fengcheng Wu, Ying-Shuang Fu
Intervalley coherent (IVC) phase in graphene systems arises from the coherent superposition of wave functions of opposite valleys, whose direct microscopic visualization provides pivotal insight into the emergent physics but remains elusive. Here, we successfully visualize the IVC phase in a heterostructure of monolayer PtSe2 on highly oriented pyrolytic graphite. Using spectroscopic imaging scanning tunneling microscopy, we observe a Root3 by Root3 modulation pattern superimposed on the higher-order moire superlattice of the heterostructure, which correlates with a small gap opening around the Fermi level and displays an anti-phase real-space conductance distribution of the two gap edges. Such modulation pattern and small-gap vanish on the heterostructure of monolayer PtSe2 on bilayer-graphene-covered SiC substrate, due to the increased carrier density in the bilayer graphene. We provide a theoretical mechanism that the Root3 by Root3 modulation pattern originates from the IVC phase of few-layer graphene, which is magnified by the higher-order moire superlattice. Our work achieves visualization of the IVC phase, and develops an avenue for its generation and amplification via a moiré interface.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
16 pages, 4 figures
Reentrant topological phases and spin density wave induced by 1D moir'e potentials
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-01-06 00:00 EST
Guo-Qing Zhang, Ling-Zhi Tang, L. F. Quezada, Shi-Hai Dong, Dan-Wei Zhang
Exotic topological and correlated phases induced by moiré potentials have recently been explored in 2D twisted bilayer graphene systems. Here we investigate spin-\(1/2\) interacting fermionic atoms in the 1D moiré optical superlattice formed by the superposition of two commensurate potentials. We reveal the reentrant topological phases and periodic-moiré-spin density wave (PM-SDW) of the ground states in both non-interacting and interacting cases. The reentrant topological phases are driven by the moiré potential with the sequent trivial-topological-trivial-topological-trivial transition. The critical exponent of topological transitions and the localization properties of the single-particle eigenstates are studied. The PM-SDW order of the many-body ground state is contributed from the moiré potential, and is enhanced by the on-site interaction but suppressed by the nearest-neighbor interaction. Our results enrich the topological physics with multiple transitions and spin-density orders in 1D moiré systems, which might be experimentally realized with ultracold atoms in tunable optical lattices.
Quantum Gases (cond-mat.quant-gas), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Strongly Correlated Electrons (cond-mat.str-el)
11 pages, 7 figures
Acceleration of enzymatic reactions due to nearby inactive binding sites
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-01-06 00:00 EST
Many biological molecular motors and machines are driven by chemical reactions that occur in specific catalytic sites. We study whether the arrival of molecules to such an active site can be accelerated by the presence of a nearby inactive site. Our approach is based on comparing the steady-state current in simple models to reference models without an inactive site. We identify two parameter regimes in which the reaction is accelerated. We then find the transition rates that maximize this acceleration, and use them to determine the underlying mechanisms in each region. In the first regime, the inactive site stores a molecule in order to release it following a reaction, when the neighboring catalytic site is empty. In the second regime, the inactive site releases a molecule when the catalytic site is full, in order to impede the molecules from leaving the active site before they react. For the storage mechanism, which is more likely to be biologically relevant, the acceleration can reach up to 15%, depending on parameters.
Statistical Mechanics (cond-mat.stat-mech), Biological Physics (physics.bio-ph)
20 pages, 4 figures, and 6 tables
Phys. Rev. Research, v6, 043330 (2024)
Topological Anderson insulators by latent symmetry
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-01-06 00:00 EST
Jing-Run Lin, Shuo Wang, Hui Li, Zheng-Wei Zuo
Topological Anderson insulators represent a class of disorder-induced, nontrivial topological states. In this study, we propose a feasible strategy to unveil and design the latent-symmetry protected topological Anderson insulators. By employing the isospectral reduction approach from graph theory, we reduce a family of the disordered multi-atomic chains to the disordered dimerized chain characterized by energy-dependent potentials and hoppings, which exhibits the chiral symmetry or inversion symmetry. According to the topological invariants, bulk polarization, and the divergence of localization length of the topological bound edge states in the reduced disordered system, the gapped and ungapped topological Anderson states with latent symmetry could be identified in the original disordered multi-atomic systems. The concept of topological Anderson insulating phases protected by the geometric symmetries and tenfold-way classification is thus extended to the various types of latent symmetry cases. This work paves the way for exploiting topological Anderson insulators in terms of latent symmetries.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
9 pages, 5 figures, Comments are welcome
Revisiting the matrix elements of the position operator in the crystal momentum representation
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Fewer operators are more fundamental than the position operator in a crystal. But since it is not translationally invariant in crystal momentum representation (CMR), how to properly represent it is nontrivial. Over half a century, various methods have been proposed, but they often lead to either highly singular derivatives or extremely arcane expressions. Here we propose a resolution to this problem by directly computing their matrix elements between two Bloch states. We show that the position operator is a full matrix in CMR, where the off-diagonal elements in crystal momentum \(\bf k\) only appear along the direction of the position vector. Our formalism, free of singular derivative and degeneracy difficulties, can describe an array of physical properties, from intraband transitions, polarization with or without spin-orbit coupling, orbital angular momentum, to susceptibilities.
Materials Science (cond-mat.mtrl-sci), Optics (physics.optics)
Decoupling the effects of ripples from tensile strain on the thermal conductivity of graphene and understanding the role of curvature on the thermal conductivity of graphene with grain boundaries
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
Abhishek Kumar, Kunwar Abhikeern, Amit Singh
Ripples, curvature, and grain boundaries in graphene can significantly alter its thermal conductivity (TC), which is paramount in various applications including thermal management etc. In this study, we conducted extensive equilibrium MD simulations and used the Green-Kubo method to elucidate the impact of ripples on the TC of graphene and the impact of curvature and tilt angles characterizing a grain boundary (GB) on the TC of polycrystalline graphene. Although tensile and compressive strains have been known to control the amount of ripples, the effects of strain and ripple on the TC have not been decoupled. With the help of Green-Kubo simulations on larger graphene samples and simulations based on the spectral energy density method on smaller samples without ripples, we show that both samples show an approximately 30% decrease in TC between tensile strains 3% and 10% when ripples become negligible even in the larger sample. Between 0 and 3% strain, when both ripples and strains are present in the larger sample, we decouple the effect of ripples from strain on the TC and show that ripples alone reduce the TC of the larger unstrained sample by approximately 61%. We also present a unique technique to introduce curvatures in the graphene sheet containing GBs by performing MD simulations under NPT ensembles with a constant pressure of 200 bar along the x-axis. Our analysis suggests that the Green-Kubo TC linearly decreases with curvature; however, the rate of decrease depends on the tilt angles of the grain boundary. An analysis of the TC in graphene samples with GBs of varying tilt angles reveals that the TC strongly depends on the tilt angles. Thus, our research underscores the pivotal role of ripple, curvature, and GB in modulating the thermal conductivity of graphene.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Enhanced Condensation Through Rotation
New Submission | Superconductivity (cond-mat.supr-con) | 2025-01-06 00:00 EST
Maxim Chernodub, Frank Wilczek
We argue that the rotation of a thin superconducting cylinder can increase the critical temperature of the superconducting phase transition substantially. The phenomenon can be interpreted as an effective negative moment of inertia associated with condensation of Cooper pairs. We give quantitative estimates for a thin cylinder of aluminum.
Superconductivity (cond-mat.supr-con), Quantum Physics (quant-ph)
5+1 pages, 1 figure
Can structure influence hydrovoltaic energy generation? Insights from the metallic 1T' and semiconducting 2H phases of MoS\(_2\)
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Kaushik Suvigya, Saini Lalita, Siva Nemala Sankar, Andrea Capasso, Li-Hsien Yeh, Kalon Gopinadhan
Hydrovoltaic power generation from liquid water and ambient moisture has attracted considerable research efforts. However, there is still limited consensus on the optimal material properties required to maximize the power output. Here, we used laminates of two different phases of layered MoS\(_2\) -- metallic 1T' and semiconducting 2H -- as representative systems to investigate the critical influence of specific characteristics, such as hydrophilicity, interlayer channels, and structure, on the hydrovoltaic performance. The metallic 1T' phase was synthesized via a chemical exfoliation process and assembled into laminates, which can then be converted to the semiconducting 2H phase by thermal annealing. Under liquid water conditions, the 1T' laminates, having a channel size of 6 angstroms, achieved a peak power density of 2.0 mW m\(^{-2}\), significantly outperforming the 2H phase, lacking defined channels, that produced a power of 2.4 microW m\(^{-2}\). Our theoretical analysis suggests that energy generation in these hydrophilic materials primarily arises from electro-kinetic and surface diffusion mechanisms. These findings highlight the crucial role of phase-engineered MoS\(_2\) and underscore the potential of 2D material laminates in advancing hydrovoltaic energy technologies.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
27 Pages with Supplementary Information, 5 Main Figures, 8 Supplementary Figures, 1 Supplementary Table
Nanoscale, 2025, Advance Article
Quasi-two-dimensional magnetism and antiferromagnetic ground state in Li\(_2\)FeSiO\(_4\)
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-01-06 00:00 EST
W. Hergett, N. Bouldi, M. Jonak, C. Neef, C. Ritter, M. Abdel-Hafiez, F. Seewald, H.-H. Klauss, M. W.-Haverkort, R. Klingeler
Our experimental (neutron diffraction, Mössbauer spectroscopy, magnetic susceptibility, specific heat) and numerical studies on the evolution of short- and long-range magnetic order in \(\gamma_{\rm II}\)-Li(_2)FeSiO(_4) suggest a quasi-two-dimensional (2D) nature of magnetism. The experimental data obtained on single crystals imply long-range antiferromagnetic order below \(T_{\rm N}= 17\)~K. A broad maximum in magnetic susceptibility \(\chi\) at \(T_{\rm m}\simeq 28\)~K, observation of magnetic entropy changes up to 100~K and anisotropy in \(\chi\) are indicative of low-dimensional magnetism and suggest short-range magnetic correlations up to 200~K. Neutron diffraction shows that long-range antiferromagnetic order is characterised by the propagation vector k=(1/2,0,1/2). The ordered moment \(\mu = 2.50(2) \mu_B\) /Fe, at \(T = 1.5\)~K, is along the crystallographic \(a\)-axis. This is consistent with the observed static hyperfine field of \(B_{\rm hyp}=14.8(3)\),T by Mössbauer spectroscopy which indicates significant orbital contributions. The temperature dependence of \(B_{\rm hyp}\) yields the critical exponent \(\beta=0.116(12)\) which is in the regime of the 2D Ising behaviour. LSDA+U studies exploiting the experimental spin structure suggest dominating magnetic exchange coupling within the \(ac\)-layers (i.e., \(J_3\simeq -6\)~K and \(J_6\simeq-2\)~K) while interlayer coupling is much smaller and partly frustrated. This confirms the 2D nature of magnetism and is in full agreement with the experimental findings.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci)
Dynamic wetting of concentrated granular suspensions
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-01-06 00:00 EST
Reza Azizmalayeri, Peyman Rostami, Thomas Witzmann, Christopher O. Klein, Günter K. Auernhammer
Many materials, such as paints and inks used in applications like painting and 3D printing, are concentrated granular suspensions. In such systems, the contact line dynamics and the internal structure of the suspension interact through shear-rate dependent viscosity and internal structural rearrangements. The shear rate increases sharply near moving contact lines, profoundly influencing the non-Newtonian rheology of dense suspensions. Frictional contacts become significant as particles approach each other, forming force-carrying networks of contacts. While hydrodynamic solutions can describe dilute suspensions, their applicability near advancing contact lines in dense suspensions remains unclear. This study explores such applicability by systematically varying inter-particle interactions. We use silica suspensions in two refractive-index matched media: (i) aqueous 2,\(2^{\prime}\)-thiodiethanol (weak interactions) and (ii) aqueous sodium thiocyanate solution (strong interactions). The two samples vary substantially in their rheological response. Using astigmatism particle tracking velocimetry (APTV), we precisely track the 3D motion of tracer particles within the suspension. To observe the drop over a long travel distance, we use a configuration consisting of a pinned droplet on a moving substrate. We observe distinct behaviours depending on particle interactions and the resulting suspension rheology. The more the particle interactions play a role, i.e., the more pronounced the non-Newtonian effects, the stronger the measured flow profiles differ from the Newtonian solution to the hydrodynamic equations. In case of the viscous suspension, a notable deviation from Newtonian behaviour is observed. Conversely, the yield-stress suspension exhibits plug flow over the substrate, with Newtonian-like behaviour restricted to the yielded region near the substrate.
Soft Condensed Matter (cond-mat.soft)
Energy spectra and fluxes of two-dimensional turbulent quantum droplets
New Submission | Quantum Gases (cond-mat.quant-gas) | 2025-01-06 00:00 EST
Shawan Kumar Jha, Mahendra K. Verma, S. I. Mistakidis, Pankaj Kumar Mishra
We explore the energy spectra and associated fluxes of turbulent two-dimensional quantum droplets subjected to a rotating paddling potential which is removed after a few oscillation periods. A systematic analysis on the impact of the characteristics (height and velocity) of the rotating potential and the droplet atom number reveals the emergence of different dynamical response regimes. These are classified by utilizing the second-order sign correlation function and the ratio of incompressible versus compressible kinetic energies. They involve, vortex configurations ranging from vortex dipoles to vortex clusters and randomly distributed vortex-antivortex pairs. The incompressible kinetic energy spectrum features Kolmogorov (\(k^{-5/3}\)) and Vinen like (\(k^{-1}\)) scaling in the infrared regime, while a \(k^{-3}\) decay in the ultraviolet captures the presence of vortices. The compressible spectrum shows \(k^{-3/2}\) scaling within the infrared and \(k\) power law in the case of enhanced sound-wave emission suggesting thermalization. Significant distortions are observed in the droplet periphery in the presence of a harmonic trap. A direct energy cascade (from large to small length scales) is mainly identified through the flux. Our findings offer insights into the turbulent response of exotic phases-of-matter, featuring quantum fluctuations, and may inspire investigations aiming to unravel self-similar nonequilibrium dynamics.
Quantum Gases (cond-mat.quant-gas)
18pages, 10 figures
Kinetic Model of the Emergence of Autocatalysis
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-01-06 00:00 EST
P. O. Mchedlov-Petrosyan, L. N. Davydov
We develop a formal model of the emergence of self-constructing objects (e.g. heteropolymers with autocatalytic capability) in an open system, which don't contain such objects initially. The objects are constructed from subunits (e.g. monomers). Each object is characterized by the difference of self-instructed reproduction and decomposition rate only. This difference, divided by a common dimensional constant, is called ``productivity''. Due to external influence the productivity of each object can randomly change. The system as a whole is subjected to external limitation: the total number of the objects is conserved (e.g., by the controlled influx of monomers). We consider such process as possibly simplest example of self-organization. We obtained exact solutions of our model for several presumed mechanisms of random change of the productivity. We have shown that the probability to find self-constructing objects in the system necessarily increases, even if initially it was equal to zero.
Statistical Mechanics (cond-mat.stat-mech), Mathematical Physics (math-ph), Probability (math.PR)
17 pages, without figures
Ohm's law, Joule heat, and Planckian dissipation
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-01-06 00:00 EST
We will show that the Planckian dissipation observed in strange metals including cuprate superconductors can be attributed to the dissipation due to the gauge fluctuation of the Berry connection. In the due course, we revisit the well-studied dissipation problem, Joule heating by electric current in metallic wires. It is known that Poynting's theorem explains it in a strange manner: The energy for the Joule heat enters from the outside of the wire as radiation; and consumed in the wire. This explanation is rectified by considering the generation of the chemical potential gradient inside the wire by the battery connection. Then, the Joule heat is obtained as the energy of the emitted radiation from the wire with its energy supplied by the connected battery. We also examine discharging of a capacitor and supercurrent flow through the Josephson junction.
Strongly Correlated Electrons (cond-mat.str-el), Classical Physics (physics.class-ph), Quantum Physics (quant-ph)
Exciton Dynamics and Quantum Efficiencies in Optically Coupled OLEDs: A Unified Quantum Master Equation Approach
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Olli Siltanen, Kimmo Luoma, Konstantinos S. Daskalakis
The primary function of organic light-emitting diodes (OLEDs) is to convert electrons into photons. However, only 25 % of the electronic states (singlets) in electrically excited fluorescent molecules can emit light, which is why triplet harvesting has attracted significant attention. Specifically, one often aims to maximize the rate of triplet-to-singlet conversion, while at the same time, it is crucial to depopulate the singlets fast enough -- before they convert to triplets or interact with other excited states, potentially breaking molecular bonds. Planar microcavities provide a viable architecture to address these issues. By confining the emitters within planar microcavities one can couple the excitons to cavity modes and engineer the population dynamics to one's liking. While the weak-coupling regime is renowned for Purcell-enhanced emission, strongly coupled excitons and photons hybridize to form entirely new energy eigenstates known as polaritons. To fully understand and optimize exciton-photon interactions and light-emission mechanisms across various coupling regimes, a unified theory of optically coupled (and uncoupled) OLEDs is needed. In this article, we introduce a quantum master equation model spanning the zero-, weak-, and strong-coupling regimes. We derive the different rates using Fermi's golden rule and Marcus theory, show how the different regimes converge, and finally evaluate the internal quantum efficiencies in all cases.
Materials Science (cond-mat.mtrl-sci), Quantum Physics (quant-ph)
13 pages, 3 figures, 1 table
Reconfigurable Filamentary Conduction in Thermally Stable Zeolitic Imidazolate Framework (ZIF-8) Resistive Switching Devices
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Divya Kaushik, Nitin Kumar, Harshit Sharma, Pukhraj Prajapat, Mehamalini V., G.Sambandamurthy, Ritu Srivastava
The rapid growth of digital technology has driven the need for efficient storage solutions, positioning memristors as promising candidates for next-generation non-volatile memory (NVM) due to their superior electrical properties. Organic and inorganic materials each offer distinct advantages for resistive switching (RS) performance, while hybrid materials like metal-organic frameworks (MOFs) combine the strengths of both. In this study, we present a resistive random-access memory (ReRAM) device utilizing zeolitic imidazolate framework (ZIF-8), a MOF material, as the resistive switching layer. The ZIF-8 film was synthesized via a simple solution process method at room temperature and subsequently characterized. The Al/ZIF-8/ITO device demonstrates bipolar resistive switching behaviour with an on/off resistance ratio of 100, stable retention up to 10000 seconds, and consistent performance across 60 cycles while exhibiting robust thermal stability from -20 C to 100 C. Low-frequency noise and impedance spectroscopy measurements suggest a filamentary switching mechanism. Additionally, the memory state can be tuned by adjusting the reset voltage, pointing to potential as multi-level memory. Potentiation and depression experiments further highlight the devices promise for neuromorphic applications. With high stability, tunability, and strong performance, the ZIF-8 based ReRAM shows great promise for advanced NVM and neuromorphic computing applications.
Materials Science (cond-mat.mtrl-sci), Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Projected ensemble in a system with conserved charges with local support
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-01-06 00:00 EST
Sandipan Manna, Sthitadhi Roy, G. J. Sreejith
The investigation of ergodicity or lack thereof in isolated quantum many-body systems has conventionally focused on the description of the reduced density matrices of local subsystems in the contexts of thermalization, integrability, and localization. Recent experimental capabilities to measure the full distribution of quantum states in Hilbert space and the emergence of specific state ensembles have extended this to questions of {}, by introducing the notion of the {} -- ensembles of pure states of a subsystem obtained by projective measurements on its complement. While previous work examined chaotic unitary circuits, Hamiltonian evolution, and systems with global conserved charges, we study the projected ensemble in systems where there are an extensive number of conserved charges all of which have (quasi)local support. We employ a strongly disordered quantum spin chain which shows many-body localized dynamics over long timescales as well as the \(\ell\)-bit model, a phenomenological archetype of a many-body localized system, with the charges being \(1\)-local in the latter. In particular, we discuss the dependence of the projected ensemble on the measurement basis. Starting with random direct product states, we find that the projected ensemble constructed from time-evolved states converges to a Scrooge ensemble at late times and in the large system limit except when the measurement operator is close to the conserved charges. This is in contrast to systems with global conserved charges where the ensemble varies continuously with the measurement basis. We relate these observations to the emergence of Porter-Thomas distribution in the probability distribution of bitstring measurement probabilities.
Statistical Mechanics (cond-mat.stat-mech), Disordered Systems and Neural Networks (cond-mat.dis-nn), Quantum Physics (quant-ph)
Electronic band structures of topological kagome materials
New Submission | Strongly Correlated Electrons (cond-mat.str-el) | 2025-01-06 00:00 EST
Man Li, Huan Ma, Rui Lou, Shancai Wang
The kagome lattice has garnered significant attention due to its ability to host quantum spin Fermi liquid states. Recently, the combination of unique lattice geometry, electron-electron correlations, and adjustable magnetism in solid kagome materials has led to the discovery of numerous fascinating quantum properties. These include unconventional superconductivity, charge and spin density waves (CDW/SDW), pair density waves (PDW), and Chern insulator phases. These emergent states are closely associated with the distinctive characteristics of the kagome lattice's electronic structure, such as van Hove singularities, Dirac fermions, and flat bands, which can exhibit exotic quasi-particle excitations under different symmetries and magnetic conditions. Recently, various quantum kagome materials have been developed, typically consisting of kagome layers stacked along the \(z\)-axis with atoms either filling the geometric centers of the kagome lattice or embedded between the layers. In this topical review, we begin by introducing the fundamental properties of several kagome materials. To gain an in-depth understanding of the relationship between topology and correlation, we then discuss the complex phenomena observed in these systems. These include the simplest kagome metal \(T_3X\), kagome intercalation metal \(TX\), and the ternary compounds \(AT_6X_6\) and \(RT_3X_5\) (\(A\) = Li, Mg, Ca, or rare earth; \(T\) = V, Cr, Mn, Fe, Co, Ni; \(X\) = Sn, Ge; \(R\) = K, Rb, Cs). Finally, we provide a perspective on future experimental work in this field.
Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), Superconductivity (cond-mat.supr-con)
Invited Review
Chin. Phys. B 34, 017101 (2025)
Light Interaction With a Space-Time-Modulated Josephson Junction Array and Application to Angular-Frequency Beam Multiplexing
New Submission | Superconductivity (cond-mat.supr-con) | 2025-01-06 00:00 EST
Josephson junctions, as pivotal components of modern technologies such as superconducting quantum computing, owe their prominence to their unique nonlinear properties at low temperatures. Despite their extensive use in static configurations, the study of dynamic Josephson junctions, particularly under space-time modulation, remains largely unexplored. This study investigates the interaction and transmission of electromagnetic waves through arrays of space-time-modulated Josephson junctions. A comprehensive mathematical framework is presented to model the propagation of electric and magnetic fields within and beyond these structures. We demonstrate how such dynamic arrays enable groundbreaking four-dimensional light manipulation, achieving angular-frequency beam multiplexing through a seamless integration of frequency conversion and beam-splitting functionalities. These advancements open new horizons for electromagnetic field engineering, with far-reaching implications for superconducting quantum technologies, next-generation wireless communications, biomedical sensing, and radar systems.
Superconductivity (cond-mat.supr-con), Optics (physics.optics)
The coherence peak of unconventional superconductors in the charge channel
New Submission | Superconductivity (cond-mat.supr-con) | 2025-01-06 00:00 EST
Pengfei Li, Zheng Li, Kun Jiang
In this work, we carry out a systematic investigation of the coherence peak in unconventional superconductors as they transition into the superconducting phase at \(T_c\). Using \(d\)-wave cuprates as an example, we reveal the presence of a coherence peak below \(T_c\) in the charge channel. The nuclear quadrupole relaxation rate is shown to be an effective method for detecting this unconventional coherence peak, with the superconducting coherence factor playing a pivotal role in its emergence. Additionally, we explore the influence of correlation effects, which further enhance this phenomenon. Extending our analysis, we demonstrate the existence of a similar coherence peak in ultrasonic attenuation and iron-based superconductors. Our findings offer a fresh perspective on probing superconducting gap symmetry in unconventional superconductors.
Superconductivity (cond-mat.supr-con), Strongly Correlated Electrons (cond-mat.str-el)
5 pages, 3 figures
A self-learning magnetic Hopfield neural network with intrinsic gradient descent adaption
New Submission | Disordered Systems and Neural Networks (cond-mat.dis-nn) | 2025-01-06 00:00 EST
Chang Niu, Huanyu Zhang, Chuanlong Xu, Wenjie Hu, Yunzhuo Wu, Yu Wu, Yadi Wang, Tong Wu, Yi Zhu, Yinyan Zhu, Wenbin Wang, Yizheng Wu, Lifeng Yin, Jiang Xiao, Weichao Yu, Hangwen Guo, Jian Shen
Physical neural networks using physical materials and devices to mimic synapses and neurons offer an energy-efficient way to implement artificial neural networks. Yet, training physical neural networks are difficult and heavily relies on external computing resources. An emerging concept to solve this issue is called physical self-learning that uses intrinsic physical parameters as trainable weights. Under external inputs (i.e. training data), training is achieved by the natural evolution of physical parameters that intrinsically adapt modern learning rules via autonomous physical process, eliminating the requirements on external computation this http URL, we demonstrate a real spintronic system that mimics Hopfield neural networks (HNN) and unsupervised learning is intrinsically performed via the evolution of physical process. Using magnetic texture defined conductance matrix as trainable weights, we illustrate that under external voltage inputs, the conductance matrix naturally evolves and adapts Oja's learning algorithm in a gradient descent manner. The self-learning HNN is scalable and can achieve associative memories on patterns with high similarities. The fast spin dynamics and reconfigurability of magnetic textures offer an advantageous platform towards efficient autonomous training directly in materials.
Disordered Systems and Neural Networks (cond-mat.dis-nn), Applied Physics (physics.app-ph)
21 pages, 5 figures
Proc. Natl. Acad. Sci. U.S.A. 121 (51) e2416294121,(2024)
Linear Scaling Calculation of Atomic Forces and Energies with Machine Learning Local Density Matrix
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
Zaizhou Xin, Yang Zhong, Xingao Gong, Hongjun Xiang
Accurately calculating energies and atomic forces with linear-scaling methods is a crucial approach to accelerating and improving molecular dynamics simulations. In this paper, we introduce HamGNN-DM, a machine learning model designed to predict atomic forces and energies using local density matrices in molecular dynamics simulations. This approach achieves efficient predictions with a time complexity of O(n), making it highly suitable for large-scale systems. Experiments in different systems demonstrate that HamGNN-DM achieves DFT-level precision in predicting the atomic forces in different system sizes, which is vital for the molecular dynamics. Furthermore, this method provides valuable electronic structure information throughout the dynamics and exhibits robust performance.
Materials Science (cond-mat.mtrl-sci), Chemical Physics (physics.chem-ph), Computational Physics (physics.comp-ph)
13 pages, 6 figures
Dynamical electron-phonon vertex correction
New Submission | Materials Science (cond-mat.mtrl-sci) | 2025-01-06 00:00 EST
The dynamical screening of the electron-phonon vertex is due to the retarded oscillations of the electronic charge following the phonon annihilation into an electron-hole pair. This retardation induces a frequency dependence of the electron-phonon interaction that is commonly neglected. In this work I propose a dynamical perturbative expansion that, while being diagrammatically consistent, defines a controllable and physically sound method to include dynamical screening effects in the electron-phonon vertex. The method is applied to the phonon self-energy of the homogeneous electron gas where I show how retardation effects are driven by the ratio between the plasma and the phonon frequencies. I finally propose a simple approach to estimate the importance of dynamical corrections. This method is applied to the paradigmatic case of MgB\(_2\) to show the non--perturbative and large retardation effects that characterize this peculiar material.
Materials Science (cond-mat.mtrl-sci)
Dense array of elastic hairs obstructing a fluidic channel
New Submission | Soft Condensed Matter (cond-mat.soft) | 2025-01-06 00:00 EST
Dense arrays of soft hair-like structures protruding from surfaces in contact with fluids are ubiquitous in living systems. Fluid flows can easily deform these soft hairs which in turn impacts the flow properties. At the microscale, flows are often confined which exacerbates this feedback loop since the hair deformation has a strong impact on the flow geometry. Here, I investigate experimentally and theoretically pressure driven flows in laminar channels obstructed by a dense array of elastic hairs. I show that the system displays a nonlinear hydraulic resistance that I model by treating the hair bed as a deformable porous media. The porous media height and thus degree of confinement results from the deflection of individual hairs. The resulting fluid-structure interaction model is leveraged to identify the dimensionless drag force \(\hat{f}_0\) controlling the elasto-viscous coupling and used to design passive flow control elements for microfluidic networks.
Soft Condensed Matter (cond-mat.soft), Fluid Dynamics (physics.flu-dyn)
High critical field superconductivity in a 3d dominated lightweight equiatomic high entropy alloy
New Submission | Superconductivity (cond-mat.supr-con) | 2025-01-06 00:00 EST
S. Jangid, P. K. Meena, R. K. Kushwaha, S. Srivastava, P. Manna, S. Sharma, P. Mishra, R. P. Singh
The lightweight high entropy alloy represents an innovative class of multicomponent systems that combine low density with the exceptional mechanical properties of high-entropy alloys. We present a detailed synthesis and investigation of a 3d rich equiatomic high entropy alloy superconductor Sc-Ti-V-Nb-Cu, which crystallizes in a body-centered cubic structure. Magnetization, electrical resistivity, and heat capacity measurements confirm weakly coupled bulk type II superconductivity with a 7.21(3) K transition temperature and an upper critical field of 12.9(1) T. The upper critical field approaches the Pauli paramagnetic limit, suggesting potential unconventional behavior. The low density, moderate transition temperature, and high upper critical field stand out Sc-Ti-V-Nb-Cu as a promising candidate for next-generation superconducting device applications.
Superconductivity (cond-mat.supr-con)
6 pages. 5 figures
Out-of-plane Edelstein effects: Electric-field induced magnetization in \(p\)-wave magnets
New Submission | Mesoscale and Nanoscale Physics (cond-mat.mes-hall) | 2025-01-06 00:00 EST
In-plane magnetization is induced by the Edelstein effect in the Rashba spin-orbit interaction system. However, out-of-plane magnetization is more useful for switching a ferromagnetic memory. We study analytically and numerically electric-field induced magnetization in \(p\)-wave magnets with the aid of the Rashba interaction based on a simple two-band model. The out-of-plane magnetization is induced when the Néel vector of the \(p\)-wave magnet is along the \(z\) direction. We also show that no magnetization is induced in the absence of the Rashba interaction. The electric-field induced magnetization will be useful for future switching technology of ferromagnetic memories based on the \(p\)-wave magnet.
Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
5 pages, 5 figures
Stochastic Thermodynamics of the Two-Dimensional Model of Transistors
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-01-06 00:00 EST
We adopt a stochastic approach to study the charge transport in transistors. In this approach, the hole and electron densities are ruled by diffusion-reaction stochastic partial differential equations satisfying local detailed balance condition. The electric field is supposed to be concentrated in very narrow regions around the two junctions and is also approximated to be static. In this way, not only the laws of electricity, thermodynamics, and microreversibility is consistent within this approach, but also the transistor can be easily modeled as a two-dimensional system. We perform the full counting statistics of the two coupled currents, and the fluctuation theorem is shown to hold. Moreover, we show that the geometric shape of the transistor exert great influence on the transport behavior. By modeling the transistor in two dimensions, the signal-amplification factor up to about \(164\) can be achieved, which is comparable to the typical value of realistic transistors in industry.
Statistical Mechanics (cond-mat.stat-mech)
14 pages, 3 figures
Responses for one-dimensional quantum spin systems via tensor networks
New Submission | Statistical Mechanics (cond-mat.stat-mech) | 2025-01-06 00:00 EST
Tensor networks are adopted to calculate the responses for one-dimensional quantum spin systems that are initially in thermal equilibrium. The Ising chain in mixed transverse and longitudinal fields is used as the benchmarking system. The linear and second-order responses of the magnetization in \(z\)-direction induced by the time-dependent force conjugated with the magnetization in \(x\)-direction are calculated. In addition, the magnetization in \(z\)-direction is also exactly calculated in response to this excitation. As expected, the first two responses are shown to be excellent corrections to the equilibrium magnetization in \(z\)-direction when the excitation is weak. This result represents an illustrative example of the response theory for nontrivial quantum many-body systems.
Statistical Mechanics (cond-mat.stat-mech), Quantum Physics (quant-ph)
9 pages, 6 figures