Temperature Dependence of the Electron LandégFactor in GaAs

The temperature dependent frequency of quantum beats of free electron Larmor precession in bulk GaAs yields the temperature variation from 5 to 200 K of the Landé $g$ factor with high accuracy. The Landé $g$ factor increases from $-0.44\mathrm{}$ to $-0.38\mathrm{}$ to $-0.35\mathrm{}$ as the temperature increases from 5 to 100 to 150 K. The experimental results are in the opposite direction than prediction by $\overrightarrow{k}̇\overrightarrow{p}$ theory manifesting the need for appreciable, temperature dependent corrections of this band model.