Spin noise spectroscopy in semiconductors.

Spin noise spectroscopy in semiconductors is an optical method that allows nearly perturbation free measurements of the spin dynamics of electrons in thermal equilibrium. The article explains the basic principles of spin noise spectroscopy and introduces an optimized experimental setup which promotes spin noise spectroscopy to an extraordinary sensitive tool. Exemplary measurements on n-doped bulk GaAs yield the temperature dependence of the electron spin relaxation time and the electron Landé g factor and reveal a dependence of the spin relaxation time on the laser probe wavelength. The magnitude and wavelength dependence of the measured spin noise signal compares well to basic calculations.