Higher-order topological insulator in cubic semiconductor quantum wells

TL;DR

This paper predicts higher-order topological insulator states in common semiconductor quantum wells, revealing new topological phases with potential for accessible material applications.

Contribution

It theoretically demonstrates the existence of topological corner states in quantum wells of common semiconductors, extending topological insulator concepts to practical materials.

Findings

Topological corner states exist in cubic semiconductor quantum wells.

Corner states depend on growth orientation, not just crystallographic orientation.

Results extend topological insulator applications to widely used semiconductors.

Abstract

The search for exotic new topological states of matter in widely accessible materials, for which the manufacturing process is mastered, is one of the major challenges of the current topological physics. Here we predict higher order topological insulator state in quantum wells based on the most common semiconducting materials. By successively deriving the bulk and boundary Hamiltonians, we theoretically prove the existence of topological corner states due to cubic symmetry in quantum wells with double band inversion. We show that the appearance of corner states does not depend solely on the crystallographic orientation of the meeting edges, but also on the growth orientation of the quantum well. Our theoretical results significantly extend the application potential of topological quantum wells based on IV, II-VI and III-V semiconductors with diamond or zinc-blende structures.