Anomalous valley Hall effect in two-dimensional multiferroic V2N2O semiconductor

Intrinsic ferromagnetism, with coexisting ferroelectric and ferrovalley polarizations in a single two-dimensional semiconductor, is highly desirable for developing next-generation multifunctional nanospintronic devices. Based on first-principles calculations and Monte Carlo simulations, the two-dimensional V2N2O monolayer is predicted to be an indirect bandgap ferromagnetic semiconductor, characterized by a near-room-temperature Curie temperature and an out-of-plane easily magnetized axis. Interestingly, the spontaneous valley polarization can be effectively modulated by the ferroelectric polarization. Remarkably, the anomalous valley Hall effect in the V2N2O monolayer can be controlled by reversing the magnetization. Thus, the V2N2O monolayer is considered a potential candidate for polymorphic memory and multifunctional valley electronic devices.