Multifunctional Antiferromagnetic Materials with Giant Piezomagnetism and Noncollinear Spin Current

TL;DR

This paper introduces a novel spin-valley locking mechanism in antiferromagnetic materials, enabling control over spin and valley degrees of freedom through crystal symmetry breaking, with potential for multifunctional spintronic applications.

Contribution

It proposes the C-paired spin-valley locking concept, predicts its realization in monolayer V2Se2O, and demonstrates giant piezomagnetism and large spin current generation.

Findings

C-paired SVL links spin/valley with real space via crystal symmetry.

Monolayer V2Se2O exhibits giant piezomagnetism.

Material can generate large transverse spin currents.

Abstract

We propose a new type of spin-valley locking (SVL), named $\textit{C}$-paired SVL, in antiferromagnetic systems, which directly connects the spin/valley space with the real space, and hence enables both static and dynamical controls of spin and valley to realize a multifunctional antiferromagnetic material. The new emergent quantum degree of freedom in the $\textit{C}$-paired SVL is comprised of spin-polarized valleys related by a crystal symmetry instead of the time-reversal symmetry. Thus, both spin and valley can be accessed by simply breaking the corresponding crystal symmetry. Typically, one can use a strain field to induce a large net valley polarization/magnetization and use a charge current to generate a large noncollinear spin current. We predict the realization of the $\textit{C}$-paired SVL in monolayer V$_2$Se$_2$O, which indeed exhibits giant piezomagnetism and can generate a large transverse spin current. Our findings provide unprecedented opportunities to integrate various controls of spin and valley with nonvolatile information storage in a single material, which is highly desirable for versatile fundamental research and device applications.