Supercurrent-induced Skyrmion dynamics and Tunable Weyl points in Chiral Magnet with Superconductivity

TL;DR

This paper explores how superconductivity influences skyrmion dynamics and Weyl points in chiral magnets, revealing tunable topological features and efficient skyrmion control via supercurrents.

Contribution

It introduces a supercurrent-induced spin torque mechanism and demonstrates tunable Weyl points in a superconductor-chiral magnet heterostructure, advancing topological spintronics.

Findings

Supercurrent-induced spin torque efficiently drives skyrmions with reduced Joule heating.

Weyl points in quasiparticle bands can be tuned by magnetization direction.

Tilt of Weyl cones is adjustable via spin-orbit coupling strength.

Abstract

Recent studies show superconductivity provides new perspectives on spintronics. We study a heterostructure composed of an s-wave superconductor and a cubic chiral-magnet that can stabilize a topological spin texture, a skyrmion. We propose a supercurrent-induced spin torque that originates from the spin-orbit coupling, and we show that the spin torque can drive a skyrmion in an efficient way that reduces Joule heating. We also study the band structure of Bogoliubov quasiparticles and show the existence of Weyl points, whose positions can be controlled by the direction of the magnetization. This results in an effective magnetic field acting on the quasiparticles in the presence spin textures. Furthermore, the tilt of the Weyl cones can also be tuned by the strength of the spin-orbit coupling, and we propose a possible realization of type-II Weyl points.