Edge states in two-dimensional electron gas with heterogeneous spin-orbit interaction

TL;DR

This paper demonstrates the existence of edge states with chiral spin textures in 2D electron gases with heterogeneous spin-orbit interactions, revealing novel boundary phenomena and size quantization effects.

Contribution

It introduces the concept of edge states in 2D electron systems with heterogeneous SOI, expanding understanding beyond topological insulators.

Findings

Edge states exist at boundaries with different SOI regions or without SOI.

Edge states can appear within forbidden or conduction bands.

Unusual size quantization dependence on strip width.

Abstract

We show that edge states similar to those known for topological insulators exist in two-dimensional electron system with one-band spectrum in the presence of heterogeneous spin-orbit interaction (SOI). These states appear at boundaries between regions with the SOIs of different kind or between the regions with the SOI and without it. Depending on the system parameters they can appear in an energy range lying both in the forbidden and conduction bands of bulk states. The edge states have chiral spin texture and carry a spin current under the equilibrium. We study also the size quantization of the edge states in a strip structure with two boundaries to find an unusual dependence of the quantization energy on the strip width.