Geometrical protection of topological magnetic solitons in microprocessed chiral magnets

Abstract

A chiral soliton lattice stabilized in a monoaxial chiral magnet ${\mathrm{CrNb}}_{3}{\mathrm{S}}_{6}$ is a magnetic superlattice consisting of magnetic kinks with a ferromagnetic background. The magnetic kinks are considered to be topological magnetic solitons (TMSs). Changes in the TMS number yield discretized responses in magnetization and electrical conductivity, and this effect is more prominent in smaller crystals. We demonstrate that, in microprocessed ${\mathrm{CrNb}}_{3}{\mathrm{S}}_{6}$ crystals, TMSs are geometrically protected through element-selected micromagnetometry using soft x-ray magnetic circular dichroism (MCD). A series of x-ray MCD data is supported by mean-field and micromagnetic analyses. By designing the microcrystal geometry, TMS numbers can be successfully changed and fixed over a wide range of magnetic fields.