Spin splitting in GaAs (100) two-dimensional holes

We measured Shubnikov–de Haas (SdH) oscillations in GaAs (100) two-dimensional holes to determine the inversion asymmetry-induced spin splitting. The Fourier spectrum of the SdH oscillations contains two peaks, at frequencies f_- and f₊, that correspond to the hole densities of the two spin subbands and a peak, at frequency f_tot, corresponding to the total hole density. In addition, the spectrum exhibits an anomalous peak at f_tot/2. We also determined the effective masses of the two spin subbands by finding the inverse transform of the Fourier spectrum in the vicinity of f_- and f₊, and then analyzing the temperature dependence of the SdH oscillations for each subband. We discuss our results in light of self-consistent calculations and previous experiments.