Chiral Interface States and Related Quantized Transport in Disordered Chern Insulators

TL;DR

This paper investigates how disordered Chern insulators exhibit chiral interface states and quantized transport, which can be controlled via potential strength and Fermi energy, with implications for broader experimental realization.

Contribution

It reveals the emergence and controllability of chiral interface states in disordered Chern insulators through potential manipulation and demonstrates their universality.

Findings

Chiral interface states appear along step potential interfaces.

Quantized transport energy range can be tuned by potential strength.

Chiral states can be spatially shifted by changing Fermi energy.

Abstract

In this Letter, we study an Anderson-localization-induced quantized transport in disordered Chern insulators (CIs). By investigating the disordered CIs with a step potential, we find that the chiral interface states emerge along the interfaces of the step potential, and the energy range for such quantized transport can be manipulated through the potential strength. Furthermore, numerical simulations on cases with a multi-step potential demonstrate that such chiral state can be spatially shifted by varying the Fermi energy, and the energy window for quantized transport is greatly enlarged. Experimentally, such chiral interface states can be realized by imposing transverse electric field, in which the energy window for quantized transport is much broader than the intrinsic band gap of the corresponding CI. These phenomena are quite universal for disordered CIs due to the direct phase transition between the CI and the normal insulator.