Chern Numbers for Spin Models of Transition Metal Nanomagnets
Mesoscale and Nanoscale Physics
2009-11-10 v1
Abstract
We argue that ferromagnetic transition metal nanoparticles with fewer than approximately 100 atoms can be described by an effective Hamiltonian with a single giant spin degree of freedom. The total spin of the effective Hamiltonian is specified by a Berry curvature Chern number that characterizes the topologically non-trivial dependence of a nanoparticle's many-electron wavefunction on magnetization orientation. The Berry curvatures and associated Chern numbers have a complex dependence on spin-orbit coupling in the nanoparticle and influence the semiclassical Landau-Liftshitz equations that describe magnetization orientation dynamics.
Keywords
Cite
@article{arxiv.cond-mat/0303555,
title = {Chern Numbers for Spin Models of Transition Metal Nanomagnets},
author = {C. M. Canali and A. Cehovin and A. H. MacDonald},
journal= {arXiv preprint arXiv:cond-mat/0303555},
year = {2009}
}