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Related papers: Negative Temperature in Spin Dynamics Simulations

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Complex environments, such as molecular matrices and biological material, play a fundamental role in many important dynamic processes in condensed phases. Because it is extremely difficult to conduct full quantum dynamics simulations on…

Quantum Physics · Physics 2022-01-03 Kiyoto Nakamura , Yoshitaka Tanimura

We review some recent results on finite dimensional spin glasses by studying recent numerical simulations and their relationship with experiments. In particular we will show results obtained at zero and non zero temperature, focusing in the…

Condensed Matter · Physics 2009-09-29 J. J. Ruiz-Lorenzo

A dipolar coupled spin system can achieve internal thermodynamic equilibrium states at negative absolute temperature. We study analytically and numerically the temperature dependence of the concurrence in a dipolar coupled spin-1/2 system…

Quantum Physics · Physics 2013-11-15 Gregory B. Furman , Victor M. Meerovich , Vladimir L. Sokolovsky

A unified model of molecular and atomistic spin dynamics is presented enabling simulations both in microcanonical and canonical ensembles without the necessity of additional phenomenological spin damping. Transfer of energy and angular…

This paper presents a systematic study of the application of convolutional neural networks (CNNs) as an efficient and versatile tool for the analysis of critical and low-temperature phase states in spin system models. The problem of…

Computational Physics · Physics 2025-12-09 Dmitrii Kapitan , Pavel Ovchinnikov , Konstantin Soldatov , Petr Andriushchenko , Vitalii Kapitan

We calculate the real time non-equilibrium dynamics of quantum spin systems at finite temperatures. The mathematical framework originates from the $C^*$-approach to quantum statistical mechanics and is applied to samples investigated by…

Mesoscale and Nanoscale Physics · Physics 2015-06-16 Kolja Them , T. Stapelfeldt , E. Y. Vedmedenko , R. Wiesendanger

The thermodynamic properties of ferromagnetic spin chains have been the subject of many publications. Still, the problem of how the spin-wave interaction manifest itself in these low-temperature series has been neglected. Using the method…

Strongly Correlated Electrons · Physics 2015-06-16 Christoph P. Hofmann

We consider the Curie-Weiss model at a given initial temperature in vanishing external field evolving under a Glauber spin-flip dynamics corresponding to a possibly different temperature. We study the limiting conditional probabilities and…

Mathematical Physics · Physics 2015-05-18 Victor Ermolaev , Christof Kuelske

We investigate the thermal properties of interacting spin-orbit coupled bosons with contact interactions in two spatial dimensions. To that end, we implement the complex Langevin method, motivated by the appearance of a sign problem, on a…

Quantum Gases · Physics 2020-04-01 Felipe Attanasio , Joaquín E. Drut

Do negative absolute temperatures matter physics and specifically Statistical Physics? We provide evidence that we can certainly answer positively to this vexata quaestio. The great majority of models investigated by statistical mechanics…

Statistical Mechanics · Physics 2021-07-07 Marco Baldovin , Stefano Iubini , Roberto Livi , Angelo Vulpiani

Low-temperature thermodynamics of the classical frustrated ferromagnetic spin chain near the ferromagnet-helimagnet transition point is studied by means of mapping to the continuum limit. The calculation of the partition function and spin…

Statistical Mechanics · Physics 2015-05-19 D. V. Dmitriev , V. Ya. Krivnov

A method is proposed to study the finite-temperature behaviour of small magnetic clusters based on solving the stochastic Landau-Lifshitz-Gilbert equations, where the effective magnetic field is calculated directly during the solution of…

Materials Science · Physics 2014-05-23 L. Rózsa , L. Udvardi , L. Szunyogh

We propose that negative absolute temperatures in ultracold atomic clouds in optical lattices can be used to simulate quantum systems in new regions of phase diagrams. First we discuss how the attractive SU(3) Hubbard model in three…

Quantum Gases · Physics 2012-04-19 Akos Rapp

We investigate the magnetic properties of a range of low-dimensional ferromagnets using a combination of first-principles calculations and atomistic spin dynamics simulations. This approach allows us to evaluate the ground state and finite…

Materials Science · Physics 2016-11-26 Lars Bergqvist , Andrea Taroni , Anders Bergman , Corina Etz , Olle Eriksson

The spherical model for spins describes ferromagnetic phase transitions well, but it fails at low temperatures. A quantum version of the spherical model is proposed. It does not induce qualitative changes near the phase transition. However,…

Condensed Matter · Physics 2009-10-22 Th. M. Nieuwenhuizen

The search for problems where quantum adiabatic optimization might excel over classical optimization techniques has sparked a recent interest in inducing a finite-temperature spin-glass transition in quasi-planar topologies. We have…

Disordered Systems and Neural Networks · Physics 2018-05-28 Zheng Zhu , Andrew J. Ochoa , Helmut G. Katzgraber

Hybrid quantum systems consisting of a collection of N spin-1/2 particles uniformly interacting with an electromagnetic field, such as one confined in a cavity, are important for the development of quantum information processors and will be…

Quantum Physics · Physics 2024-12-04 Lane G. Gunderman , Troy Borneman , David G. Cory

Atom counting theory can be used to study the role of thermal noise in quantum phase transitions and to monitor the dynamics of a quantum system. We illustrate this for a strongly correlated fermionic system, which is equivalent to an…

Inspired by path integral molecular dynamics, we build a spin model, in terms of spin coherent states, from which we can compute the quantum expectation values of a spin in a constant magnetic field, at finite temperature. This formulation…

Materials Science · Physics 2023-11-02 Thomas Nussle , Stam Nicolis , Joseph Barker

We study the effect of coupling a spin bath environment to a system which, at low energies, can be modeled as a quantum Ising system. A field theoretic formalism incorporating both thermal and quantum fluctuations is developed to derive…

Strongly Correlated Electrons · Physics 2018-07-04 R. D. McKenzie , P. C. E Stamp