Solving spin quantum-master equations with matrix continued-fraction methods: application to superparamagnets
Statistical Mechanics
2009-11-11 v2 Mesoscale and Nanoscale Physics
Quantum Physics
Abstract
We implement continued-fraction techniques to solve exactly quantum master equations for a spin with arbitrary S coupled to a (bosonic) thermal bath. The full spin density matrix is obtained, so that along with relaxation and thermoactivation, coherent dynamics is included (precession, tunnel, etc.). The method is applied to study isotropic spins and spins in a bistable anisotropy potential (superparamagnets). We present examples of static response, the dynamical susceptibility including the contribution of the different relaxation modes, and of spin resonance in transverse fields.
Cite
@article{arxiv.cond-mat/0603730,
title = {Solving spin quantum-master equations with matrix continued-fraction methods: application to superparamagnets},
author = {J. L. Garcia-Palacios and D. Zueco},
journal= {arXiv preprint arXiv:cond-mat/0603730},
year = {2009}
}
Comments
Resubmitted to J. Phys. A: Math. Gen. Some rewriting here and there. Discussion on positivity in App.D3 at request of one referee