关键词: intrinsic ferrovalley, anomalous valley Hall effect, first-principles calculations

Abstract: Manipulation of the valley degree of freedom provides a new path for quantum information technology, but the real intrinsic large valley-polarization materials are rarely reported up to date. Here, we perform first-principles calculations to predict a class of 2H-phase single layer (SL) materials Lu$X_{2}$ ($X ={\rm Cl}$, Br, I) to be ideal candidates. SL-Lu$X_{2}$ are ferrovalley materials with a giant valley-polarization of 55 meV-148 meV as a result of its large spin-orbital coupling (SOC) and intrinsic ferromagnetism (FM). The magnetic transition temperatures of SL-LuI$_{2}$ and SL-LuCl$_{2}$ are estimated to be 89 K-124 K, with a sizable magnetic anisotropy at out-of-plane direction. Remarkably, the anomalous valley Hall effect (AVHE) can be controlled in SL-Lu$X_{2}$ when an external electric field is applied. Moreover, the intrinsic valley-polarization of SL-LuI$_{2}$ is highly robust for biaxial strain. These findings provide a promising ferrovalley material system for the experimentation of valleytronics and subsequent applications.

Key words: intrinsic ferrovalley, anomalous valley Hall effect, first-principles calculations