Switchable in-plane anomalous Hall effect by magnetization orientation in monolayer Mn3Si2Te6

In-plane anomalous Hall effect (IPAHE) is an unconventional anomalous Hall effect (AHE) where the Hall current flows in the plane spanned by the magnetization or magnetic field and the electric field. Here, we predict a stable two-dimensional ferromagnetic monolayer ${\mathrm{Mn}}_{3}{\mathrm{Si}}_{2}{\mathrm{Te}}_{6}$ with collinear ordering of Mn moments in the basal plane. Moreover, we reveal that monolayer ${\mathrm{Mn}}_{3}{\mathrm{Si}}_{2}{\mathrm{Te}}_{6}$ possesses a substantial periodic IPAHE due to the threefold rotational symmetry, which can be switched by changing the magnetization orientation by external magnetic fields. In addition, we briefly discuss the impacts of moderate strains on the electronic states and the AHE, which lead to a near quantized Hall conductivity. Our work provides a potential platform for realizing a sizable and controllable IPAHE that greatly facilitates the application of energy-efficient spintronic devices.