Chiral topological excitonic insulator in semiconductor quantum wells

TL;DR

This paper proposes a method to realize and detect chiral topological excitonic insulators in semiconductor quantum wells with ferromagnetic films, characterized by TKNN and winding numbers, and measurable via thermal conductance.

Contribution

It introduces a feasible experimental scheme to realize and distinguish chiral topological excitonic phases in semiconductor heterostructures.

Findings

Chiral topological excitonic insulators can be realized in semiconductor quantum wells.

Different topological orders are characterized by TKNN and winding numbers.

Thermal conductance measurements can detect chiral edge states.

Abstract

We present a scheme to realize the chiral topological excitonic insulator in semiconductor heterostructures which can be experimentally fabricated with a coupled quantum well adjacent to twoferromagnetic insulating films. The different mean-field chiral topological orders, which are due to the change in the directions of the magnetization of the ferromagnetic films, can be characterized by the TKNN numbers in the bulk system as well as by the winding numbers of the gapless states in the edged system. Furthermore, we propose an experimental scheme to detect the emergence of the chiral gapless edge state and distinguish different chiral topological orders by measuring the thermal conductance.