Spin Transfer Torques in MnSi at Ultra-low Current Densities

TL;DR

This study demonstrates that in MnSi, ultra-low electric currents can manipulate magnetic skyrmion lattices, revealing highly efficient spin-current coupling in bulk materials, which could advance low-power spintronic applications.

Contribution

First observation of current-induced rotation of skyrmion lattice diffraction patterns in bulk MnSi at ultra-low current densities, highlighting efficient spin-current coupling.

Findings

Magnetic diffraction pattern rotates with ultra-low currents

Current densities are over five orders of magnitude lower than previous studies

Coupling between inhomogeneous spin currents and topological spin structures is highly efficient

Abstract

Spin manipulation using electric currents is one of the most promising directions in the field of spintronics. We used neutron scattering to observe the influence of an electric current on the magnetic structure in a bulk material. In the skyrmion lattice of MnSi, where the spins form a lattice of magnetic vortices similar to the vortex lattice in type II superconductors, we observe the rotation of the diffraction pattern in response to currents which are over five orders of magnitude smaller than those typically applied in experimental studies on current-driven magnetization dynamics in nanostructures. We attribute our observations to an extremely efficient coupling of inhomogeneous spin currents to topologically stable knots in spin structures.