Ferroelectric antiferromagnetic quantum anomalous Hall insulator in two-dimensional van der Waals materials

Ferroelectricity (FE), antiferromagnetism (AFM), and the quantum anomalous Hall (QAH) effect are three fundamental phenomena in condensed-matter physics that could enable the realization of novel devices, thereby attracting substantial attention. Here, we show theoretical evidence that two-dimensional (2D) even-layer MnBi₂Te₄ allows for the simultaneous presence of FE, AFM, and the QAH effect. Importantly, through rational van der Waals sliding, these exotic properties are strongly coupled. Such coupling could demonstrate distinctive physics, such as the ferroelectric control of the magnetic spin distribution in the AFM phase and the sign of the quantized anomalous Hall plateau. The explored phenomena and mechanisms would not only enrich research in 2D ferroelectricity and topological magnets but also guide the design of low-consumption, high-speed quantum devices.