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

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.