Skyrmion Lattice Manipulation with Electric Currents and Thermal Gradients in MnSi

TL;DR

This study investigates how electric currents and thermal gradients influence the orientation of skyrmion lattices in MnSi, revealing complex, non-monotonic reorientation behaviors driven by competing effects and supported by micromagnetic simulations.

Contribution

It demonstrates the controlled manipulation of skyrmion lattice orientation using combined electric and thermal currents, highlighting the interplay of these effects in MnSi.

Findings

SkL reorients non-monotonically with increasing current.

Reorientation depends on local current density and thermal effects.

Micromagnetic simulations support the experimental observations.

Abstract

The skyrmion lattice (SkL) in MnSi was studied using small-angle neutron scattering and under the influence of a radial electric current in a Corbino geometry. In response to the applied current, the SkL undergoes an angular reorientation with respect to the MnSi crystal lattice. The reorientation is non-monotonic with increasing current, with the SkL rotating first in one direction and then the other. The SkL reorientation was studied at different sample locations and found to depend on the local current density as inferred from a finite element analysis. The non-monotonic response indicates the presence of two competing effects on the SkL, most likely due to the presence of both radial electric and thermal currents. Such a scenario is supported by micromagnetic simulations, which show how these effects can act constructively or destructively to drive the SkL rotation, depending on the direction of the electric current. In addition, the simulations also suggest how the direction of the skyrmion flow may affect the SkL orientation.