Electrically Controllable van der Waals Antiferromagnetic Spin Valve

TL;DR

This paper introduces an electrically controllable van der Waals antiferromagnetic spin valve that leverages bilayer graphene encapsulated by Cr$_2$Ge$_2$Te$_6$ to achieve significant magnetoresistance changes through electric bias manipulation.

Contribution

It presents a novel fully electrically controlled spin valve based on van der Waals antiferromagnetism with a practical material platform for implementation.

Findings

Magnetoresistance varies significantly with bias orientation.

Bilayer graphene with Cr$_2$Ge$_2$Te$_6$ provides a robust antiferromagnetic platform.

Device operation is controlled by vertical electric fields.

Abstract

We propose a spin valve that is based on van der Waals antiferromagnetism and fully electrically controlled. The device is composed of two antiferromagnetic terminals that allow for vertical bias control and a linked central scattering potential region. The magnetoresistance varies significantly when the bias orientations in two terminals are switched from parallel to antiparallel because this switch induces a mismatch of the bands for the same spin projection in different parts of the system. It is shown from density functional calculations that bilayer graphene encapsulated by two atomic layers of Cr$_2$Ge$_2$Te$_6$ provides a material platform to realize the antiferromagnetism, which is robust against the required vertical electric fields.