Spin-orbit and exchange interaction in a HgMnTe magnetic two-dimensional electron gas
HgMnTe磁性二维电子气自旋-轨道和交换相互作用研究

Spin orbit interaction and sp d exchange interaction are investigated by analyzing beating patterns of Shubnikov de Hass oscillations in a HgMnTe magnetic two dimensional electron gas (2DEG) at various temperatures. The results show that (1) spin orbit interaction results in zero magnetic field spin splitting in 2DEG; (2) spin orbit interaction is dominant at low magnetic field, and the total spin splitting decreases with increasing magnetic field due to the influence of Landau splitting and Zeeman splitting; (3) at a high magnetic field, the sp d exchange interaction tends to saturate and the spin splitting corresponds to Zeeman splitting. The experiments demonstrate that the spin splitting deduced from fast Fourier transformation (FFT) of SdH oscillations versus. 1/ B is different from zero magnetic field spin splitting when Zeeman spin splitting is comparable to zero magnetic field spin splitting.