Electrical Control of Spin-polarized Topological Currents in Monolayer WTe$_2$

TL;DR

This paper demonstrates that small electric fields can coherently manipulate the spin orientation of topological edge states in monolayer WTe2, enabling potential spintronic applications with topological protection.

Contribution

It introduces a method for electrical control of spin textures in a quantum spin Hall insulator, combining simulations and modeling to show efficient spin rotation without losing topological properties.

Findings

Electric fields can rotate edge state spins by up to 90 degrees.

Spin textures are controllable without destroying topological protection.

Potential for gate-controlled topological spintronic devices.

Abstract

We evidence the possibility for coherent electrical manipulation of the spin orientation of topologically protected edge states in a low-symmetry quantum spin Hall insulator. By using a combination of ab-initio simulations, symmetry-based modeling, and large-scale calculations of the spin Hall conductivity, it is shown that small electric fields can efficiently vary the spin textures of edge currents in monolayer 1T'-WTe2 by up to a 90-degree spin rotation, without jeopardizing their topological character. These findings suggest a new kind of gate-controllable spin-based device, topologically protected against disorder and of relevance for the development of topological spintronics.