Electron g‐factor fluctuations in highly n‐doped GaAs at high temperatures detected by ultrafast spin noise spectroscopy

Recent spin noise spectroscopy measurements showed at low temperatures unexpected large g‐factor fluctuations in highly n‐doped bulk GaAs which were attributed to intrinsic g‐factor fluctuations due to the stochastic nature of the doping distribution. In this publication, we extend these low temperature magnetic field dependent spin noise measurements from 20 up to 260 K. A global fit of all magnetic field and temperature dependent measurements with just three common fit parameters yields good qualitative agreement with the stochastic doping model taking into account the dominating electron momentum scattering by ionized impurities and electron–plasmon scattering which contribute about equally. The magnetic field dependent Larmor precession of the electron spin yields for the studied doping concentration of 8.5×1017cm−3 a reduction of the electron Landé g‐factor due to bandgap renormalization of −0.03. However, the analysis also reproduces the previously observed quantitative difference between the measured g‐factor fluctuations and predictions by the semiclassical stochastic doping model.