Ferroelectric tuning of the valley polarized metal-semiconductor transition in Mn2P2S3Se3/Sc2CO2 van der Waals heterostructures and application to nonlinear Hall effect devices

TL;DR

This paper demonstrates how ferroelectric substrates can control valley polarization and phase transitions in 2D materials, enabling tunable nonlinear Hall effect devices for nano-spintronic applications.

Contribution

It introduces a novel mechanism for manipulating valley and phase transitions in 2D materials using ferroelectric substrates, with detailed microscopic insights.

Findings

Valley polarized metal-semiconductor transition can be tuned by ferroelectric polarization switching.

Berry curvature dipole can be flexibly manipulated via polarization direction.

Proposes a new platform for designing nonlinear Hall effect devices.

Abstract

In order to promote the development of the next generation of nano-spintronic devices, it is of great significance to tune the freedom of valley in two-dimensional (2D) materials. Here, we propose a mechanism for manipulating the valley and nonlinear Hall effect by the 2D ferroelectric substrate. The monolayer Mn2P2S3Se3 is a robust antiferromagnetic valley polarized semiconductor. Importantly, the valley polarized metal-semiconductor phase transition of Mn2P2S3Se3 can be effectively tuned by switching the ferroelectric polarization of Sc2CO2. We reveal the microscopic mechanism of phase transition, which origins from the charge transfer and band alignment. Additionally, we find that transformed polarization direction of Sc2CO2 flexibly manipulate the Berry curvature dipole. Based on this discovery, we present the detection valley polarized metal-semiconductor transition by the nonlinear Hall effect devices. These findings not only offer a scheme to tune the valley degree of freedom, but also provide promising platform to design the nonlinear Hall effect devices.