Spin-orbit lateral superlattices: energy bands and spin polarization in 2DEG

TL;DR

This paper investigates the energy bands and spin polarization in a 2D electron gas with Rashba spin-orbit interaction under a 1D periodic potential, revealing spin wave behavior, anticrossings, and effects of magnetization.

Contribution

It provides a detailed analysis of spinor symmetry, standing spin wave states, and spin flip phenomena in spin-orbit superlattices, including optical and magnetization effects.

Findings

Bloch spinors form standing spin waves with superlattice wavelength.

Anticrossing of energy bands causes spin flips.

Spin projections have components both parallel and transverse to the plane.

Abstract

The Bloch spinors, energy spectrum and spin density in energy bands are studied for the two-dimensional electron gas (2DEG) with Rashba spin-orbit (SO) interaction subject to one-dimensional (1D) periodic electrostatic potential of a lateral superlattice. The space symmetry of the Bloch spinors with spin parity is studied. It is shown that the Bloch spinors at fixed quasimomentum describe the standing spin waves with the wavelength equal to the superlattice period. The spin projections in these states have the components both parallel and transverse to the 2DEG plane. The anticrossing of the energy dispersion curves due to the interplay between the SO and periodic terms is observed, leading to the spin flip. The relation between the spin parity and the interband optical selection rules is discussed, and the effect of magnetization of the SO superlattice in the presence of external electric field is predicted.