Light-engineered Multichannel Quantum Anomalous Hall Effect in High-order Topological Plumbene

TL;DR

This paper predicts tunable high-Chern-number quantum anomalous Hall states in plumbene under circularly polarized light, revealing a three-stage topological phase transition with potential for advanced electronic devices.

Contribution

It introduces a light-induced, multi-stage topological phase transition in plumbene, demonstrating high-order topological states with high Chern numbers and tunability via substrate effects.

Findings

Predicted a three-stage topological phase transition in plumbene under circularly polarized light.

Identified high Chern number QAH states, including C = -8, -6, and -3, depending on conditions.

Showed substrate effects can eliminate valley-based topology, leaving a single high-Chern-number state.

Abstract

Floquet engineering severs as a forceful technique for uncovering high Chern numbers of quantum anomalous Hall (QAH) states with feasible tunability in high-order topologically insulating plumbene, which is readily accessible for experimental investigations. Under the irradiation of righthanded circularly polarized light, we predict a three-stage topological phase transition in plumbene, whether it is in a free-standing form or grown on h-BN. Initially, a metallic state evolves into a K(K')-valley-based QAH state with a Chern number of -8, which then decreases to -6 after the valley gap closes. Finally, a band inversion occurs at the $\Gamma$ point, resulting in a multichannel QAH state with C = -3. The trigonal warping model accounts for both K(K')-valley-based and $\Gamma$-pointbased QAH states. Additionally, growing plumbene on a non-van-der-Waals substrate eliminates the K(K')-valley-based topology, leaving only the $\Gamma$-point-based QAH state with C = +3. Our findings propose the tunability of various high Chern numbers derived from high-order topological insulators, aiming to advance the next-generation dissipationless electronic devices.