Topological Insulating States in Laterally Patterned Ordinary Semiconductors

TL;DR

This paper demonstrates that ordinary semiconductors with strong spin-orbit coupling, when patterned with specific potentials, can host stable, tunable topological states with sizable electronic gaps, potentially operable at practical temperatures.

Contribution

It introduces a method to realize topological insulators in common semiconductors using quantum confinement and patterned potentials, expanding the material base for topological states.

Findings

Electronic gaps supporting chiral edge states can be as large as the miniband bandwidth.

Lithographic technology can produce topological insulators functioning at 10-100K.

Potential for room temperature tunable topological insulators with improved fabrication.

Abstract

We propose that ordinary semiconductors with large spin-orbit coupling (SOC), such as GaAs, can host stable, robust, and {\it tunable} topological states in the presence of quantum confinement and superimposed potentials with hexagonal symmetry. We show that the electronic gaps which support chiral spin edge states can be as large as the electronic bandwidth in the heterostructure miniband. The existing lithographic technology can produce a topological insulator (TI) operating at temperature $10- 100K$. Improvement of lithographic techniques will open way to tunable room temperature TI.