Prediction of intrinsic ferrovalley characteristic in MoGeSi2Se6 monolayer

Abstract

Two-dimensional (2D) ferrovalley materials, which exhibit spontaneous valley polarization, have emerged as promising candidates for designing valleytronic devices. From an application perspective, the ferrovalley material that possesses perpendicular magnetic anisotropy and sizable valley polarization is highly desirable. Based on first-principles calculations, we propose that the 2D MoGeSi₂Se₆ monolayer harbors the desired ferrovalley property. This ferromagnetic monolayer is thermodynamically stable and demonstrates an out-of-plane easy magnetization axis. When the spin–orbit coupling is incorporated, a valley polarization of up to 76.44 meV is spontaneously generated in the conduction band. With its valley-contrasting Berry curvature, the MoGeSi₂Se₆ monolayer can produce the anomalous valley Hall effect (AVHE) under an in-plane electric field. Furthermore, the applications of biaxial strain and vertical electric field allow for effective manipulations of magnetic anisotropy energy and valley polarization. The excellent magnetic and electronic properties make the MoGeSi₂Se₆ monolayer an appealing candidate for future experimental investigations and practical applications.