Spin noise of itinerant fermions
Abstract
We develop a theory of spin noise spectroscopy of itinerant, noninteracting, spin-carrying fermions in different regimes of temperature and disorder. We use kinetic equations for the density matrix in spin variables. We find a general result with a clear physical interpretation, and discuss its dependence on temperature, the size of the system, and applied magnetic field. We consider two classes of experimental probes: 1. electron-spin-resonance (ESR)-type measurements, in which the probe response to a uniform magnetization increases linearly with the volume sampled, and 2. optical Kerr/Faraday rotation-type measurements, in which the probe response to a uniform magnetization increases linearly with the length of the light propagation in the sample, but is independent of the cross section of the light beam. Our theory provides a framework for interpreting recent experiments on atomic gases and conduction electrons in semiconductors and provides a baseline for identifying the effects of interactions on spin noise spectroscopy.
Keywords
Cite
@article{arxiv.0911.4578,
title = {Spin noise of itinerant fermions},
author = {Simon Kos and Alexander V. Balatsky and Peter B. Littlewood and Darryl L. Smith},
journal= {arXiv preprint arXiv:0911.4578},
year = {2015}
}