Designer spin-orbit superlattices: symmetry-protected Dirac cones and spin Berry curvature in two-dimensional van der Waals metamaterials

TL;DR

This paper demonstrates how patterned heterostructures with tunable spin-orbit coupling can create mini-band structures with Dirac cones and large spin Berry curvature, enabling controllable spintronic effects in 2D materials.

Contribution

It introduces a novel approach to engineer relativistic band structures in 2D van der Waals materials via lateral patterning of spin-orbit coupling.

Findings

Patterned heterostructures exhibit mini-bands with Dirac cones.

Large spin Berry curvature is present in the mini-bands.

Gate-tunable spin Hall responses are achievable.

Abstract

The emergence of strong relativistic spin-orbit effects in low-dimensional systems provides a rich opportunity for exploring unconventional states of matter. Here, we present a route to realise tunable relativistic band structures based on the lateral patterning of proximity-induced spin-orbit coupling. The concept is illustrated on a patterned graphene-transition metal dichalcogenide heterostructure, where the spatially periodic spin-orbit coupling induces a rich mini-band structure featuring massless and massive Dirac bands carrying large spin Berry curvature. The envisaged systems support robust and gate-tunable spin Hall responses driven by the quantum geometry of mini-bands, which can be tailored through metasurface fabrication methods and twisting effects. These findings open pathways to two-dimensional quantum material design and low-power spintronic applications.