Impact of the skyrmion spin texture on magnetoresistance

Skyrmions are topological knots in the magnetization, and they can be stabilized as particle-like states in a ferromagnetic environment. Due to their noncollinear spin texture, the local density of states is modified, and they are thus electronically different from their ferromagnetic surroundings. Exploiting the spatial and energy resolution of scanning tunneling microscopy and spectroscopy this work demonstrates how the local spin configuration within a skyrmion modifies the respective differential conductance. This noncollinear magnetoresistance (NCMR) can reach values of 50% in Pd/Fe/Ir(111) and allows imaging of skyrmions with nonmagnetic probe electrodes. Because of its large signal and the reduced technical requirements, NCMR is expected to be useful for the detection of the magnetic state with planar tunnel junctions in skyrmionic spintronics applications.