Spin noise spectroscopy of atomic vapors and semiconductors

Spin noise spectroscopy (SNS) is a powerful technique to passively
probe spin dynamics in atomic vapors and semiconductors by detecting
Faraday rotation fluctuations of a linearly polarized off-resonant
laser beam passing through the sample. The SNS has been useful to
measure various spin properties including hyperfine coupling in atomic
vapors, electron spin life-time in semiconductors and anisotropic hole
g-factor of self-assembled quantum dots. I will start my talk by
introducing physics of SNS. Next I will show our results on detection
of correlations between two spin-resonances using a double-frequency
SNS with an additional radio-frequency magnetic field along with the
probe laser beam. Finally I will discuss our recent proposal to
measure spin-spin correlations between two interacting spin subsystems
using a two-color SNS with two linearly polarized laser beams of
different wavelength. The spin-spin correlations have been probed
experimentally following our proposal.