Resonant spin polarization in a two-dimensional hole gas: Effect of the Luttinger term, structural inversion asymmetry and Zeeman splitting

TL;DR

This paper investigates how electric fields induce resonant spin polarization in a 2D hole gas, highlighting the effects of the Luttinger term, structural asymmetry, and magnetic field, with potential applications in spin control.

Contribution

It reveals the interplay between Luttinger Hamiltonian components and structural asymmetry in producing and tuning resonant spin polarization in 2D hole gases.

Findings

Resonant peaks occur at specific magnetic fields due to band splitting.

Structural asymmetry influences the resonance structure and magnetic field requirements.

Lower temperatures enhance the height and weight of the resonant peaks.

Abstract

The electric-field-induced resonant spin polarization of a two-dimensional hole gas described by Luttinger Hamiltonian with structural inversion asymmetry and Zeeman splitting in a perpendicular magnetic field was studied. The spin polarization arising from splitting between the light and the heavy hole bands shows a resonant peak at a certain magnetic field. Especially, the competition between the Luttinger term and the structural inversion asymmetry leads to a rich resonant peaks structure, and the required magnetic field for the resonance may be effectively reduced by enlarging the effective width of the quantum well. Furthermore, the Zeeman splitting tends to move the resonant spin polarization to a relative high magnetic field and destroy these rich resonant spin phenomena. Finally, both the height and the weight of the resonant peak increase as the temperature decreases. It is believed that such resonant spin phenomena can be verified in the sample of a two-dimensional hole gas, and it may provide an efficient way to control spin polarization by an external electric field.