Spin–orbit torque emerging from orbital textures in centrosymmetric materials

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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow/> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ). 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.