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arXiv · 1201.6316

Bloch-Redfield theory of high-temperature magnetic fluctuations in interacting spin systems

Andrew Sykes·Dmitry Solenov·Dmitry Mozyrsky
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Abstract

We study magnetic fluctuations in a system of interacting spins on a lattice at high temperatures and in the presence of a spatially varying magnetic field. Starting from a microscopic Hamiltonian we derive effective equations of motion for the spins and solve these equations self-consistently. We find that the spin fluctuations can be described by an effective diffusion equation with a diffusion coefficient which strongly depends on the ratio of the magnetic field gradient to the strength of spin-spin interactions. We also extend our studies to account for external noise and find that the relaxation times and the diffusion coefficient are mutually dependent.

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Andrew Sykes, Dmitry Solenov, Dmitry Mozyrsky. 2012-01-30. Bloch-Redfield theory of high-temperature magnetic fluctuations in interacting spin systems. https://doi.org/10.1103/physrevb.85.174419

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