Temperature-dependent electron Landé $g$ factor and the interband matrix element of GaAs

Very high precision measurements of the electron Landé $g$ factor in GaAs are presented using spin-quantum beat spectroscopy at low excitation densities and temperatures ranging from 2.6 to 300 K. In colligation with available data for the temperature-dependent effective mass temperature dependence of the interband matrix element within a common five-level $\mathbf{k}\cdot \mathbf{p}$ theory can model both parameters consistently. A strong decrease in the interband matrix element with increasing temperature consistently closes a long lasting gap between experiment and theory and substantially improves the modeling of both parameters.

Figure 1

(Color online) High precision measurement of the temperature dependence of the electron Landé $g$ factor in bulk GaAs (filled circles). The red solid line is a fit of the experimental data by Eq. (1) with a strong temperature-dependent interband matrix element. The green dashed line is the calculated $g^{\ast }$ with $E_P\left(T\right)$ depending only on the anharmonic lattice expansion. Both calculations contain both the dilatational and electron-phonon contribution to the change in the interband critical points according to Eq. (4) and values shown in Table .

Figure 2

(Color online) Temperature dependence of the effective conduction electron mass in bulk GaAs [hollow blue circles (Ref. 5) full black circles (Ref. 26)]. The red solid line follows Eq. (1) with a strong temperature-dependent interband matrix. The green dashed line is calculated with the conventional temperature dependence of $E_P$. Please note the different impact of $E_P$ on $g^{\ast }$ and $m^{\ast }$ according to Eqs. (1, 2).