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

Statistical Mechanics 2013-03-28 v1 Strongly Correlated Electrons

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.

Keywords

Cite

@article{arxiv.1201.6316,
  title  = {Bloch-Redfield theory of high-temperature magnetic fluctuations in interacting spin systems},
  author = {Andrew Sykes and Dmitry Solenov and Dmitry Mozyrsky},
  journal= {arXiv preprint arXiv:1201.6316},
  year   = {2013}
}