Ferrovalleytricity in a two-dimensional antiferromagnetic lattice

Abstract

Control over and manipulation of valley physics via ferrovalleytricity is highly desirable for advancing valleytronics. Current research focuses primarily on two-dimensional ferromagnetic systems, while antiferromagnetic counterparts are seldom explored. Here, we present a general mechanism for extending the ferrovalleytricity paradigm to antiferromagnetic lattices to achieve spin control over valley physics. Our symmetry analysis and k·p model reveal that by introducing a Zeeman field aroused by the proximity effect, spin-switchable non-uniform potential is imposed on the two sublattices of an antiferromagnetic lattice. This enables spin control over the anomalous valley Hall effect, thereby realizing ferrovalleytricity. This mechanism is confirmed in a CrBr₃–MnPSe₃–CrBr₃ heterotrilayer from first principles, where the spin-switchable non-uniform Zeeman effect is exerted on two Mn sublattices when the antiferromagnetic MnPSe₃ layer is sandwiched between ferromagnetic CrBr₃ layers. Such a non-uniform Zeeman effect combined with valley physics guarantees spin control over the anomalous valley Hall effect, i.e., ferrovalleytricity, in the MnPSe₃ layer. Our work will shed light on potential applications of valley physics in antiferromagnetic systems.