Nonvolatile Controlling Valleytronics by Ferroelectricity in 2H-VSe<sub>2</sub>/Sc<sub>2</sub>CO<sub>2</sub> van der Waals Heterostructure
Chengan Lei, Xilong Xu, Ting Zhang, Baibiao Huang, Ying Dai, Yandong Ma
Abstract
Controlling two-dimensional (2D) valleytronics by external means is a major challenge to better information technology. Here, we demonstrate that introducing a ferroelectric-aided layer is an extraordinary approach for realizing the nonvolatile control of 2D valleytronics. When stacking valleytronic monolayer 2H-VSe2 with ferroelectric monolayer Sc2CO2 and the ferroelectric polarization pointing along the −z direction, the system exhibits a ferromagnetic semiconducting nature and harbors rare intrinsic valley polarization, and its spontaneous valley polarization reaches 234 meV. Upon reversing its ferroelectric polarization via a short-term voltage, the ferromagnetism is preserved, but a semiconductor-to-half-metal transition occurs, erasing any possibility for valleytronics. This allows the electrical reversible control of valleytronics in a 2H-VSe2/Sc2CO2 van der Waals heterostructure through the application of a short-term voltage. Our work thus provides a promising strategy for achieving nonvolatile control of valleytronics at the nanoscale and helps the design of novel controllable devices.