Conserved Spin Quantity in Strained Hole Systems with Rashba and Dresselhaus Spin-Orbit Coupling

TL;DR

This paper derives an effective Hamiltonian for strained hole systems with Rashba and Dresselhaus spin-orbit coupling, revealing a conserved spin quantity near the Fermi surface under certain strain conditions.

Contribution

It introduces a realistic model showing conserved spin quantities in strained hole systems, extending previous work to more practical parameter regimes.

Findings

Conserved spin quantity exists near Fermi contours with uniaxial strain.

Conservation persists even at zero strain under specific conditions.

Model aligns with realistic Luttinger parameters.

Abstract

We derive an effective Hamiltonian for a (001)-confined quasi-two-dimensional hole gas in a strained zincblende semiconductor heterostructure including both Rashba and Dresselhaus spin-orbit coupling. In the presence of uniaxial strain along the $\left\langle110\right\rangle$ axes, we find a conserved spin quantity in the vicinity of the Fermi contours in the lowest valence subband. In contrast to previous works, this quantity meets realistic requirements for the Luttinger parameters. For more restrictive conditions, we even find a conserved spin quantity for vanishing strain, restricted to the vicinity of the Fermi surface.