Photoinduced Quantum Anomalous Hall States in the Topological Anderson Insulator

TL;DR

This paper proposes a method to induce quantum anomalous Hall states in topological Anderson insulators using circularly polarized light, avoiding magnetic doping and enabling high-temperature applications.

Contribution

It introduces a novel approach to realize QAH states in trivial insulators through light and disorder interplay, expanding the potential for spintronics applications.

Findings

Disorder-induced topological insulator can be transformed into QAH state with light.

Circularly polarized light breaks time-reversal symmetry in TAI.

Spin and charge Hall conductivities can distinguish topological phases.

Abstract

The realization of the quantum anomalous Hall (QAH) effect without magnetic doping attracts intensive interest since magnetically doped topological insulators usually possess inhomogeneity of ferromagnetic order. Here, we propose a different strategy to realize intriguing QAH states arising from the interplay of light and non-magnetic disorder in two-dimensional topologically trivial systems. By combining the Born approximation and Floquet theory, we show that a time-reversal invariant disorder-induced topological insulator, known as the topological Anderson insulator (TAI), would evolve into a time-reversal broken TAI and then into a QAH insulator by shining circularly polarized light. We utilize spin and charge Hall conductivities, which can be measured in experiments directly, to distinguish these three different topological phases. This work not only offers an exciting opportunity to realize the high-temperature QAH effect without magnetic orders, but also is important for applications of topological states to spintronics.