Spin torques and magnetic texture dynamics driven by the supercurrent in superconductor/ferromagnet structures

TL;DR

This paper develops a formalism to describe how supercurrents in superconductor/ferromagnet structures induce dissipationless spin torques, affecting magnetic textures like domain walls, with implications for experimental studies.

Contribution

It introduces a general formalism for supercurrent-induced spin torques in superconductor/ferromagnet systems, highlighting their effects on magnetic textures.

Findings

Supercurrents generate field-like and spin-orbital torques.

Supercurrents can shift or move magnetic domain walls.

The formalism applies to Josephson junctions and hybrid structures.

Abstract

We introduce the general formalism to describe spin torques induced by the supercurrents injected from the adjacent superconducting electrodes into the spin-textured ferromagnets. By considering the adiabatic limit for the equal-spin superconducting correlations in the ferromagnet we show that the supercurrent can generate both the field-like spin transfer torque and the spin-orbital torque. These dissipationless spin torques are expressed through the current-induced corrections to the effective field derived from the system energy. The general formalism is applied to show that the supercurrent can either shift or move the magnetic domain walls depending on their structure and the type of spin-orbital interaction in the system. These results can be used for the prediction and interpretation of the experiments studying magnetic texture dynamics in superconductor/ferromagnet/superconductor Josephson junctions and other hybrid structures.