Spin noise spectroscopy in GaAs -: art. no. 216603

We observe the noise spectrum of electron spins in bulk GaAs by Faraday-rotation noise spectroscopy. The experimental technique enables the undisturbed measurement of the electron-spin dynamics in semiconductors. We measure exemplarily the electron-spin relaxation time and the electron Lande g factor in n-doped GaAs at low temperatures and find good agreement of the measured noise spectrum with a theory based on Poisson distribution probability.