From Coupled Rashba Electron and Hole Gas Layers to 3D Topological Insulators

TL;DR

This paper proposes a layered system of Rashba electron and hole gases that, through tunnel coupling, can realize a 3D topological insulator with observable Dirac cone surface states, offering a feasible experimental platform.

Contribution

It introduces a novel layered Rashba system that can be engineered to exhibit a strong 3D topological insulator phase with specific surface state spectra.

Findings

The system exhibits a strong 3D topological insulator phase.

Surface states form an anisotropic Dirac cone.

The setup is experimentally feasible.

Abstract

We introduce a system of stacked two-dimensional electron and hole gas layers with Rashba spin orbit interaction and show that the tunnel coupling between the layers induces a strong three- dimensional (3D) topological insulator phase. At each of the two-dimensional bulk boundaries we find the spectrum consisting of a single anistropic Dirac cone, which we show by analytical and numerical calculations. Our setup has a unit-cell consisting of four tunnel coupled Rashba layers and presents a synthetic strong 3D topological insulator and is distinguished by its rather high experimental feasibility.