Spin-orbit torque emerging from orbital textures in centrosymmetric materials

TL;DR

This paper reveals a novel spin-orbit torque mechanism in centrosymmetric 2D materials driven by orbital textures, which can be harnessed for more efficient spin control in spintronic devices.

Contribution

It uncovers a new orbital texture-driven spin-orbit torque mechanism in centrosymmetric materials using first-principles and quantum transport calculations.

Findings

Orbital textures localize at opposite sides of the material.

The mechanism produces efficient, tunable spin-orbit torque.

Orbital-spin entanglement can outperform Rashba-type effects.

Abstract

We unveil a hitherto concealed spin-orbit torque mechanism driven by orbital degrees of freedom in centrosymmetric two-dimensional transition metal dichalcogenides (focusing on PtSe${}_2$ ). Using first-principles simulations, tight-binding models and large-scale quantum transport calculations, we show that such a mechanism fundamentally stems from a spatial localization of orbital textures at opposite sides of the material, which imprints their symmetries onto spin-orbit coupling effects, further producing efficient and tunable spin-orbit torque. Our study suggests that orbital-spin entanglement at play in centrosymmetric materials can be harnessed as a resource for outperforming conventional spin-orbit torques generated by the Rashba-type effects.