Deformation of the moving magnetic skyrmion lattice in MnSi under electric current flow

Topological defects are found ubiquitously in various kinds of matter, such as vortices in type-II superconductors, and magnetic skyrmions in chiral ferromagnets. While knowledge on the static behavior of magnetic skyrmions is accumulating steadily, their dynamics under forced flow is still a widely open issue. Here, we report the deformation of the moving magnetic skyrmion lattice in MnSi under electric current flow observed using small-angle neutron scattering. A spatially inhomogeneous rotation of the skyrmion lattice, with an inverse rotation sense for opposite sample edges, is observed for current densities greater than a threshold value jt ~ 1 MA m−2 (106 A m−2). Our result show that skyrmion lattices under current flow experience significant friction near the sample edges due to pinning, this being a critical effect that must be considered for anticipated skyrmion-based applications at the nanoscale. Magnetic skyrmions are topological objects that have been recently extensively studied for their particular characteristics and a view to be used in spintronics devices. The authors present a Small Angle Neutron Scattering study of the deformation of magnetic skyrmion lattice propelled by an electric current and find that the skyrmions experience frictional movement at the edges of their sample providing better understanding of the motion of skyrmions.