Ferroelectric tuning of the valley polarized metal-semiconductor transition in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>Mn</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">P</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> </mml:msub> <mml:msub> <mml:mi>Se</mml:mi> <mml:mn>3</mml:mn> </mml:msub> </mml:math> / <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mi>Sc</mml:mi> <mml:mn>2</mml:mn> </mml:msub> <mml:msub> <mml:mi>CO</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:math> van der Waals heterostructures and application to nonlinear Hall effect devices
Hanbo Sun, Yewei Ren, Chao Wu, Pengqiang Dong, Weixi Zhang, Yin-Zhong Wu, Ping Li
Abstract
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.