Chiral spin-transfer torque induced by curvature gradient

TL;DR

This paper demonstrates that a curvature gradient in a nanowire induces a chiral spin-transfer torque affecting domain wall motion and spin wave behavior, revealing a new mechanism for spin transport in spintronics.

Contribution

It introduces the concept of curvature-induced chiral spin-transfer torque and analyzes its impact on domain wall dynamics and spin waves in curved nanowires.

Findings

Curvature gradient induces a chiral spin-transfer torque.

The torque's effect depends on the domain wall orientation.

Curvature influences spin wave behavior.

Abstract

This work analyzes the propagation of a transverse domain wall (DW) motion under the action of an electric current along a nanowire (NW) with a curvature gradient. Our results evidence that the curvature gradient induces a chiral spin-transfer torque (CSTT) whose effect on the DW motion depends on the direction along which the DW points. The origin of the CSTT is explained in terms of a position and phase-dependent effective field associated with the DW profile and the electric current direction. Finally, our results reveal that this chiral mechanism can also affect the behavior of other magnetization collective modes, such as spin waves. This work shows the emergence of curvature-induced chiral spin transport and highlights a new phenomenon to be considered for designing spintronic devices.