Discrete Laplacian Thermostat for Spin Systems with Conserved Dynamics
arXiv:2212.09647 · doi:10.1103/PhysRevB.107.224302
Abstract
A well-established numerical technique to study the dynamics of spin systems in which symmetries and conservation laws play an important role is to microcanonically integrate their reversible equations of motion, obtaining thermalization through initial conditions drawn with the canonical distribution. In order to achieve a more realistic relaxation of the magnetic energy, numerically expensive methods that explicitly couple the spins to the underlying lattice are normally employed. Here we introduce a stochastic conservative thermostat that relaxes the magnetic energy while preserving the constant of motions, thus turning microcanonical spin dynamics into a conservative canonical dynamics, without actually simulating the lattice. We test the thermostat on the Heisenberg antiferromagnet in d=3 and show that the method reproduces the exact values of the static and dynamic critical exponents, while in the low-temperature phase it yields the correct spin wave phenomenology. Finally, we demonstrate that the relaxation coefficient of the new thermostat is quantitatively connected to the microscopic parameters of the spin-lattice coupling.
arXiv commentRevised version. 30 pages, 7 figures
References in corpus (18)
- Collective motion
- Atomistic spin model simulations of magnetic nanomaterials
- Superfluid transport of information in turning flocks of starlings
- Critical Exponents of the Classical 3D Heisenberg Model: A Single-Cluster Monte Carlo Study
- Flocking and turning: a new model for self-organized collective motion
- Massively parallel symplectic algorithm for coupled magnetic spin dynamics and molecular dynamics
- Precise determination of critical exponents and equation of state by field theory methods
- Dynamic scaling in natural swarms
- Dynamics of magnetization coupled to a thermal bath of elastic modes
- Natural Swarms in Dimensions
- Dynamical renormalization group approach to the collective behaviour of swarms
- Collective dynamics in atomistic models with coupled translational and spin degrees of freedom
- Spin dynamics simulations of the magnetic dynamics of RbMnF and direct comparison with experiment
- Critical dynamics of the simple-cubic Heisenberg antiferromagnet RbMnF: Extrapolation to q=0
- Renormalization group crossover in the critical dynamics of field theories with mode coupling terms
- Magnon-phonon coupling effects on the indirect K-edge resonant inelastic X-ray scattering spectrum of a 2D Heisenberg antiferromagnet
- Non-universal critical aging scaling in three-dimensional Heisenberg antiferromagnets
- Critical Dynamics of Anisotropic Antiferromagnets in an External Field