Ferrovalleytricity in a two-dimensional antiferromagnetic lattice.
Shuyan ChaiYangyang FengYing DaiBaibiao HuangLiangzhi KouYandong MaPublished in: Materials horizons (2024)
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 CrBr 3 -MnPSe 3 -CrBr 3 heterotrilayer from first principles, where the spin-switchable non-uniform Zeeman effect is exerted on two Mn sublattices when the antiferromagnetic MnPSe 3 layer is sandwiched between ferromagnetic CrBr 3 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 MnPSe 3 layer. Our work will shed light on potential applications of valley physics in antiferromagnetic systems.