Floquet quantum anomalous Hall effect with a high Chern number in nonmagnetic K2NaAs monolayer

Abstract

Featuring multiple dissipationless edge channels, the high-Chern number quantum anomalous Hall effect (QAHE) offers a highly promising platform for low-power spintronic applications. Here, we propose the emergence of QAHE with a high Chern number in two-dimensional (2D) nonmagnetic materials and, strikingly, reveal that Floquet engineering provides a versatile platform for realizing such high-Chern number QAHE, with the Chern number reaching as much as C=±3. Moreover, based on first-principles calculations, the K2NaAs monolayer is identified as an experimentally feasible candidate of the proposed mechanism of Floquet QAHE, where a topological phase transition from the 2D nonmagnetic trivial insulator to QAHE emerges. These findings establish a technological pathway linking 2D nonmagnets with exotic QAHE physics, offering promising prospects for applications in topological spintronics.