Spin Splitting in GaAs (100) Two-Dimensional Holes

TL;DR

This study investigates spin splitting in GaAs (100) two-dimensional holes by analyzing Shubnikov-de Haas oscillations, revealing details about spin subband densities, effective masses, and anomalous spectral features.

Contribution

It provides experimental measurements of spin splitting and effective masses in GaAs 2D holes, comparing results with theoretical calculations and prior experiments.

Findings

Detection of two spin subband peaks in Fourier spectrum

Measurement of effective masses for each spin subband

Observation of an anomalous spectral peak at half the total frequency

Abstract

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 $f_\mathrm{tot}$, corresponding to the total hole density. In addition, the spectrum exhibits an anomalous peak at $f_\mathrm{tot}/2$. 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.