Symmetry-Breaking Phenomena in MnPS3/TMDC Heterostructures: Non-relativistic Spin Splitting, Altermagnetism and Spin-Valley Effects

TL;DR

This study investigates how stacking configurations in MnPS3/TMDC heterostructures induce symmetry-breaking phenomena, leading to tunable spin and valley effects without net magnetization, advancing valleytronics.

Contribution

It reveals that MnPS3 can serve as a symmetry-tunable antiferromagnetic substrate to control spin and valley effects in 2D heterostructures, independent of net magnetization.

Findings

Different stacking geometries lead to distinct nonrelativistic spin splitting types.

Magnetic properties of MnPS3 are preserved upon interfacing.

Spin orientation controls conduction-valley splitting.

Abstract

We explore symmetry-breaking phenomena in MnPS3/TMDC (MoS2, WS2, MoSe2, WSe2) heterostructures using first-principles calculations, considering two high-symmetry stacking configurations, S1 and S2, which differ not only by their interfacial registry but also by a 30{\deg} twist between the layers. Depending on the stacking geometry, the systems exhibit two distinct types of nonrelativistic spin splitting (NRSS): S2 hosts altermagnetic-like band crossings, while S1 shows global spin splitting characteristic of symmetry-breaking NRSS. Magnetic exchange and anisotropy parameters indicate that the intrinsic magnetic properties of MnPS3 are largely preserved upon interfacing. Including spin-orbit coupling, we find tunable conduction-valley splitting controlled by the MnPS3 spin orientation. Our results identify MnPS3 as a symmetry-tunable antiferromagnetic substrate capable of inducing and controlling spin and valley effects in 2D heterostructures without relying on net magnetization or strong SOC, offering a route toward nonvolatile valleytronic functionalities.