Electrical control of spin and valley in spin-orbit coupled graphene multilayers

TL;DR

This paper proposes a new electrical switching mechanism for spin and valley polarization in graphene multilayers using proximity-induced spin-orbit coupling from TMD substrates, with potential applications in spintronics and valleytronics.

Contribution

It introduces a novel method for electrical control of isospin in graphene multilayers via TMD-induced spin-orbit coupling, supported by analytical and numerical analysis.

Findings

Electrical switching of spin and valley polarization demonstrated

Control achieved by reversing displacement field or chemical potential

Selective isospin flavor switching enabled by TMD alignment and gate voltages

Abstract

Electrical control of magnetism has been a major techonogical pursuit of the spintronics community, owing to its far-reaching implications for data storage and transmission. Here, we propose and analyze a new mechanism for electrical switching of isospin, using chiral-stacked graphene multilayers, such as bernal bilayer graphene or rhombohedral trilayer graphene, encapsulated by transition metal dichalcogenide (TMD) substrates. Leveraging the proximity-induced spin-orbit coupling from the TMD, we demonstrate electrical switching of correlation-induced spin and/or valley polarization, by reversing a perpendicular displacement field or the chemical potential. We substantiate our proposal with both analytical arguments and self-consistent Hartree-Fock numerics. Finally, we illustrate how the relative alignment of the TMDs, together with the top and bottom gate voltages, can be used to selectively switch distinct isospin flavors, putting forward correlated van der Waals heterostructures as a promising platform for spintronics and valleytronics.