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arXiv · 1610.04914

Pulse-noise approach for classical spin systems

D. A. Garanin
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Abstract

For systems of classical spins interacting with the bath via damping and thermal noise, the approach is suggested to replace the white noise by a pulse noise acting at regular time intervals $Δt$, within which the system evolves conservatively. The method is working well in the typical case of a small dimensionless damping constant $λ$ and allows a considerable speed-up of computations by using high-order numerical integrators with a large time step $δt$ (up to a fraction of the precession period), while keeping $δt\llΔt$ to reduce the relative contribution of noise-related operations. In cases when precession can be discarded, $δt$ can be increased up to a fraction of the relaxation time $\propto1/λ$ that leads to a further speed-up. This makes equilibration speed comparable with that of Metropolis Monte Carlo. The pulse-noise approach is tested on single-spin and multi-spin models.

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BibTeXRIS

D. A. Garanin. 2017-01-04. Pulse-noise approach for classical spin systems. https://doi.org/10.1103/physreve.95.013306

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