Ferroelectric tuning of the valley polarized metal-semiconductor transition in Mn 2 P 2 S 3 Se 3 / Sc 2 CO 2 van der Waals heterostructures and application to nonlinear Hall effect devices

作者：Hanbo Sun, Yewei Ren, Chao Wu, Pengqiang Dong, Weixi Zhang, Yin-Zhong Wu, Ping Li · 发表于：Physical Review Applied · 年份：2025 · DOI：10.1103/physrevapplied.23.034032 · 被引用次数：23 · 研究领域：2D Materials and Applications、MXene and MAX Phase Materials、Heusler alloys: electronic and magnetic properties

To promote the development of the next generation of nanospintronic devices, it is of great significance to tune the valley degree of freedom in two-dimensional (2D) materials. Here, we propose a mechanism for manipulating the valley and nonlinear Hall effect using a 2D ferroelectric substrate. Monolayer ${\mathrm{Mn}}_{2}{\mathrm{P}}_{2}{\mathrm{S}}_{3}{\mathrm{Se}}_{3}$ is a robust antiferromagnetic, valley polarized semiconductor. Importantly, the valley polarized metal-semiconductor phase transition of ${\mathrm{Mn}}_{2}{\mathrm{P}}_{2}{\mathrm{S}}_{3}{\mathrm{Se}}_{3}$ can be effectively tuned by switching the ferroelectric polarization of ${\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$. We reveal the microscopic mechanism of the phase transition, which originates from charge transfer and band alignment. Additionally, we find that the reversed polarization direction of ${\mathrm{Sc}}_{2}{\mathrm{CO}}_{2}$ can flexibly manipulate the Berry curvature dipole. Based on this discovery, we present the detection of the valley polarized metal-semiconductor transition using nonlinear Hall effect devices. These findings not only offer a scheme to tune the valley degree of freedom but also provide a promising platform for designing nonlinear Hall effect devices.