Ferroelectric Switchable Topological Antiferromagnetism

Topological magnetism features whirling spin textures protected by topology. Its effective control is of great significance for both fundamental research and device applications, yet achieved so far only in ferromagnetic systems. The inherent stability of antiferromagnetic analogues makes their control profoundly challenging. Here, through symmetry and model analysis, we demonstrate a novel ferroelectric switchable topological antiferromagnetism effect in two-dimensional multiferroics, i.e., the reversal of ferroelectric polarization is coupled to the switching of topology of antiferromagnetic spin texture─interconverting skyrmions and bimerons. The physics correlates to the polarization-dependent low-energy electronic states near the Fermi level, which modifies the single-ion anisotropy and thereby reconfigure antiferromagnetic topological spin order. We establish the design principles for the ferroelectric switchable topological antiferromagnetism. Followed by first-principles and atomistic spin model simulations, this effect is further demonstrated in AgCr2Te4/In2S3 heterobilayer. Our study opens a feasible approach toward precise control of topological antiferromagnetism.