Physical Review E最新文献

{"title":"Nonequilibrium spin transport in integrable and nonintegrable classical spin chains.","authors":"Dipankar Roy, Abhishek Dhar, Herbert Spohn, Manas Kulkarni","doi":"10.1103/PhysRevE.110.044110","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044110","url":null,"abstract":"<p><p>Anomalous transport in low dimensional spin chains is an intriguing topic that can offer key insights into the interplay of integrability and symmetry in many-body dynamics. Recent studies have shown that spin-spin correlations in spin chains, where integrability is either perfectly preserved or broken by symmetry-preserving interactions, fall in the Kardar-Parisi-Zhang (KPZ) universality class. Similarly, energy transport can show ballistic or diffusive-like behavior. Although such behavior has been studied under equilibrium conditions, no results on nonequilibrium spin transport in classical spin chains has been reported so far. In this work, we investigate both spin and energy transport in classical spin chains (integrable and nonintegrable) when coupled to two reservoirs at two different temperatures/magnetizations. In both the integrable case and the broken-integrability (but spin-symmetry preserving) case, we report anomalous scaling of spin current with system size (J^{s}∝L^{-μ}), with an exponent value that, within error bars, is close to the KPZ universality class value μ≈2/3. On the other hand, it is noteworthy that the energy current remains ballistic (J^{e}∝L^{-η} with η≈0) in the purely integrable case while there is departure from ballistic behavior (η>0) when integrability is broken regardless of spin-symmetry. We also present results on other interesting observables in the nonequilibrium steady state such as the spatial profiles of magnetization and energy, and spin-spin correlations.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044110"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical simulation of a two-dimensional Blume-Capel ferromagnet in an oscillating magnetic field with a constant bias.","authors":"Celeste Mendes, Gloria M Buendía, Per Arne Rikvold","doi":"10.1103/PhysRevE.110.044133","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044133","url":null,"abstract":"<p><p>We perform a numerical study of the kinetic Blume-Capel (BC) model to find if it exhibits the metamagnetic anomalies previously observed in the kinetic Ising model for supercritical periods [P. Riego et al., Phys. Rev. Lett. 118, 117202 (2017)0031-900710.1103/PhysRevLett.118.117202; G. M. Buendía et al., Phys. Rev. B 96, 134306 (2017)2469-995010.1103/PhysRevB.96.134306]. We employ a heat-bath Monte Carlo (MC) algorithm on a square lattice in which spins can take values of ±1,0, with a nonzero crystal field, subjected to a sinusoidal oscillating field in conjunction with a constant bias. In the ordered region, we find an equivalent hysteretic response of the order parameters with its respective conjugate fields between the kinetic and the equilibrium model. In the disordered region (supercritical periods), we observed two peaks, symmetrical with respect to zero bias, in the susceptibility and scaled variance curves, consistent with the numerical and experimental findings on the kinetic Ising model. This behavior does not have a counterpart in the equilibrium model. Furthermore, we find that the peaks occur at higher values of the bias field and become progressively smaller as the density of zeros, or the amplitude of the oscillating field, increases. Using nucleation theory, we demonstrate that these fluctuations, as in the Ising model, are not a critical phenomenon, but that they are associated with a crossover between a single-droplet (SD) and a multidroplet (MD) magnetization switching mechanism. For strong (weak) bias, the SD (MD) mechanism dominates. We also found that the zeros concentrate on the droplets' surfaces, which may cause a reduced interface tension in comparison with the Ising model [M. Schick et al., Phys. Rev. B 34, 1797 (1986)0163-182910.1103/PhysRevB.34.1797]. Our results suggest that metamagnetic anomalies are not particular to the kinetic Ising model, but rather are a general characteristic of spin kinetic models, and provide further evidence that the equivalence between dynamical phase transitions and equilibrium ones is only valid near the critical point.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044133"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SWAP algorithm for lattice spin models.","authors":"Greivin Alfaro Miranda, Leticia F Cugliandolo, Marco Tarzia","doi":"10.1103/PhysRevE.110.L043301","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.L043301","url":null,"abstract":"<p><p>We adapted the SWAP molecular dynamics algorithm for use in lattice Ising spin models. We dressed the spins with a randomly distributed length and we alternated long-range spin exchanges with conventional single spin flip Monte Carlo updates, both accepted with a stochastic rule which respects detailed balance. We show that this algorithm, when applied to the bidimensional Edwards-Anderson model, speeds up significantly the relaxation at low temperatures and manages to find ground states with high efficiency and little computational cost. The exploration of spin models should help in understanding why SWAP accelerates the evolution of particle systems and sheds light on relations between dynamics and free-energy landscapes.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4","pages":"L043301"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamical signatures of discontinuous phase transitions: How phase coexistence determines exponential versus power-law scaling.","authors":"Krzysztof Ptaszyński, Massimiliano Esposito","doi":"10.1103/PhysRevE.110.044134","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044134","url":null,"abstract":"<p><p>There are conflicting reports in the literature regarding the finite-size scaling of the Liouvillian gap and dynamical fluctuations at discontinuous phase transitions, with various studies reporting either exponential or power-law behavior. We clarify this issue by employing large deviation theory. We distinguish two distinct classes of discontinuous phase transitions that have different dynamical properties. The first class is associated with phase coexistence, i.e., the presence of multiple stable attractors of the system dynamics (e.g., local minima of the free-energy functional) in a finite phase diagram region around the phase transition point. In that case, one observes asymptotic exponential scaling related to stochastic switching between attractors (though the onset of exponential scaling may sometimes occur for very large system sizes). In the second class, there is no phase coexistence away from the phase transition point, while at the phase transition point itself there are infinitely many attractors. In that case, one observes power-law scaling related to the diffusive nature of the system relaxation to the stationary state.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044134"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pump depletion and the Raman gap in ignition-scale plasmas.","authors":"S H Cao, M J Rosenberg, A A Solodov, H Wen, C Ren","doi":"10.1103/PhysRevE.110.045202","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.045202","url":null,"abstract":"<p><p>Laser-plasma instabilities under ignition conditions for direct-drive inertial confinement fusion are studied using two-dimensional particle-in-cell simulations with a combination of in-plane (PP) and out-of-the-plane (SP) lasers. The results show that stimulated Raman side-scattering can induce significant pump depletion and form a gap in the Raman scattered-light spectra that have been observed in experiments.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-2","pages":"045202"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrostatic energy of solid binary ionic mixtures.","authors":"A A Kozhberov","doi":"10.1103/PhysRevE.110.045206","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.045206","url":null,"abstract":"<p><p>We study the electrostatic energy of binary ionic mixtures (BIMs) in the form of Coulomb crystals with the main focus on ordered crystals. We consider 15 different binary bcc-like lattices, accurately calculate their electrostatic energies, and approximate them by a unified equation. These results extend those available in the literature. A detailed comparison with selected previous results is made, particularly, using previous calculations in the linear mixing rule approximation. The case of disordered BIMs is also outlined. The results are expected to be useful for exploring multicomponent Coulomb systems in compact stars, laboratory plasmas, and technological applications.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-2","pages":"045206"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142676887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Likelihood-based inference, identifiability, and prediction using count data from lattice-based random walk models.","authors":"Yihan Liu, David J Warne, Matthew J Simpson","doi":"10.1103/PhysRevE.110.044405","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044405","url":null,"abstract":"<p><p>In vitro cell biology experiments are routinely used to characterize cell migration properties under various experimental conditions. These experiments can be interpreted using lattice-based random walk models to provide insight into underlying biological mechanisms, and continuum limit partial differential equation (PDE) descriptions of the stochastic models can be used to efficiently explore model properties instead of relying on repeated stochastic simulations. Working with efficient PDE models is of high interest for parameter estimation algorithms that typically require a large number of forward model simulations. Quantitative data from cell biology experiments usually involve non-negative cell counts in different regions of the experimental images, and it is not obvious how to relate finite, noisy count data to the solutions of continuous PDE models that correspond to noise-free density profiles. In this work, we illustrate how to develop and implement likelihood-based methods for parameter estimation, parameter identifiability, and model prediction for lattice-based models describing collective migration with an arbitrary number of interacting subpopulations. We implement a standard additive Gaussian measurement error model as well as a new physically motivated multinomial measurement error model that relates noisy count data with the solution of continuous PDE models. Both measurement error models lead to similar outcomes for parameter estimation and parameter identifiability, whereas the standard additive Gaussian measurement error model leads to nonphysical prediction outcomes. In contrast, the new multinomial measurement error model involves a lower computational overhead for parameter estimation and identifiability analysis, as well as leading to physically meaningful model predictions.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044405"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Turbulent cascade arrests and the formation of intermediate-scale condensates.","authors":"Kolluru Venkata Kiran, Dario Vincenzi, Rahul Pandit","doi":"10.1103/PhysRevE.110.L043101","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.L043101","url":null,"abstract":"<p><p>Energy cascades lie at the heart of the dynamics of turbulent flows. In a recent study of turbulence in fluids with odd viscosity X. M. de Wit et al. [Nature (London) 627, 515 (2024)0028-083610.1038/s41586-024-07074-z], the two dimensionalization of the flow at small scales leads to the arrest of the energy cascade and selection of an intermediate scale, between the forcing and the viscous scales. To demonstrate the generality of the phenomenon and its existence for a wide class of turbulent systems, we study a shell model that is carefully constructed to have three-dimensional turbulent dynamics at small wave numbers and two-dimensional turbulent dynamics at large wave numbers. The large scale separation that we can achieve in our shell model allows us to examine clearly the interplay between these dynamics, which leads to an arrest of the energy cascade at a transitional wave number and an associated accumulation of energy at the same scale. Such pile-up of energy around the transitional wave number is reminiscent of the formation of condensates in two-dimensional turbulence, but, in contrast, it occurs at intermediate wave numbers instead of the smallest wave number.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4","pages":"L043101"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avalanching behavior of magnetic granular mixtures.","authors":"Cecily Sunday, Charles T Pett, Adam Ben Youssef, Daisy Achiriloaie, Connor Churko, Daniel P Lathrop, Christine M Hartzell","doi":"10.1103/PhysRevE.110.044901","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044901","url":null,"abstract":"<p><p>We conducted avalanching experiments with an external magnetic field and granular samples of different grain sizes (3.18 mm, 6.35 mm, and 8.73 mm) and different materials (low-carbon steel, alloy steel, stainless steel, and brass). The magnetic field was varied to control the magnetic Bond number (the ratio between the magnetic and the gravitational forces in the system). For each test, we compared the angle of repose and the surface roughness of the material in its postavalanche state. The samples containing only steel beads transitioned through three flow regimes as the magnetic field increased. Initially, the grains flowed freely. Above a threshold magnetic field, the material began to move in clumps, and above a second threshold, it solidified completely. The steel-brass mixtures with low magnetic susceptibilities only transitioned through the first two states. We find that the angle of repose and surface roughness increase linearly with magnetic cohesion in the first regime, but that the trends in the second regime depend on the composition and magnetic susceptibility of the mixture. When the angle of repose and surface roughness are expressed in terms of the magnetic Bond number, the homogeneous samples that vary in grain size and magnetic susceptibility collapse onto a single curve, but the mixtures (i.e., the samples that contain more than one type of material) do not.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044901"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pseudotransitions in a dilute Ising chain.","authors":"Darya Yasinskaya, Yury Panov","doi":"10.1103/PhysRevE.110.044118","DOIUrl":"https://doi.org/10.1103/PhysRevE.110.044118","url":null,"abstract":"<p><p>This study provides a comprehensive analysis of the ground state and thermodynamic properties of a spin-pseudospin chain representing a model of a one-dimensional dilute magnet with two types of nonmagnetic charged impurities. For this purpose, a method utilizing the transfer-matrix properties is employed. Despite the wide variety of intriguing frustrated phase states, we show that the model showcases pseudotransitions solely between simple charge and magnetic quasiorders. These pseudotransitions are characterized by distinct features in the thermodynamic and magnetic quantities, resembling first- and second-order phase transitions. In addition to pseudotransitions for the \"pure\" system, similar to those observed in other one-dimensional spin models, this study also reveals the presence of \"second-order\" pseudotransitions for the dilute case. We show that the nature of these discovered pseudotransitions is associated with the phase separation in the chain into regions of (anti)ferromagnetic and charge-ordered phases. The ability to compare the results of an exact transfer-matrix calculation with a simple phenomenological description within the framework of Maxwell construction contributes to a deeper understanding of both the physical mechanisms underlying this phenomenon and the analytical methods used.</p>","PeriodicalId":48698,"journal":{"name":"Physical Review E","volume":"110 4-1","pages":"044118"},"PeriodicalIF":2.2,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142677600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}