Photoinduced spin-Hall resonance in a k^3-Rashba spin-orbit coupled two dimensional hole system

TL;DR

This paper investigates how linearly polarized light affects the band structure and spin-Hall effect in a 2D heavy-hole system with $k^3$-Rashba spin-orbit coupling, revealing light-induced anisotropy, degeneracy points, and resonant spin-Hall conductivity.

Contribution

It introduces the concept of light-induced band structure modulation and spin-Hall resonance in a $k^3$-Rashba system, highlighting the emergence of degeneracy points controlled by light intensity.

Findings

Light causes anisotropic band structure in the system.

Additional spin-degeneracy points emerge due to light, depending on light amplitude.

Spin-Hall conductivity exhibits resonance when degeneracy points are near the Fermi level.

Abstract

We study the band structure modulation and spin-Hall effect of a two-dimensional heavy-hole system with $k^3$-Rashba spin-orbit coupling (RSOC), irradiated by linearly polarized light. We find that the band structure becomes anisotropic under the illumination by the light. Most remarkably, a pair of additional spin-degeneracy points (apart from $\Gamma$ point) emerge in the energy dispersion, the locations of which are solely determined by the strength of the amplitude of the incident light. If this degeneracy occurs around the Fermi level, the spin-Hall conductivity (SHC) exhibits a resonance. Away from the degeneracy points, the light rotates the average spin polarization. The possible effects of $k^3$-Dresselhaus spin-orbit coupling are also discussed.