Probing switchable valley-related Hall effects in 2D magnetic MXenes

The search for two-dimensional materials with exotic valley-dependent properties has attracted rapid attention as they are fundamentally intriguing and practically appealing for nanoscale device applications. Here, using first-principles calculations, we report the identification of promising intrinsic valley-related switchable Hall effects in Cr2CSF. With a high out-of-plane magnetic anisotropy, Cr2CSF is a ferrovalley semiconductor with spontaneously polarized valleys having a valley polarization of 27.1 meV in the conduction band. This facilitates the observation of an intrinsic anomalous valley Hall (AVH) effect that is manipulated under an in-plane electric field. The underlying physics of spontaneous valley polarization is also discussed based on the SOC Hamiltonian model. Furthermore, on application of unidirectional compressive strain, Cr2CSF is further transitioned from the AVH phase to a long-sought quasi-half valley metal state. Here, only the electrons are valley polarized such that holes and electrons carriers are separated under the in-plane electric field. Our work enriches materials with the valley-related Hall effects and provides a platform for interplay among valleytronics and spintronics.