Data-Perpendicular reading of single confined magnetic skyrmions

Thin-film sub-5 nm magnetic skyrmions constitute an ultimate scaling alternative for future
digital data storage. Skyrmions are robust noncollinear spin textures that can be moved and
manipulated by small electrical currents. Here we show here a technique to detect isolated
nanoskyrmions with a current perpendicular-to-plane geometry, which has immediate
implications for device concepts. We explore the physics behind such a mechanism by
studying the atomistic electronic structure of the magnetic quasiparticles. We investigate
from first principles how the isolated skyrmion local-density-of-states which tunnels into
the vacuum, when compared with the ferromagnetic background, is modified by the site
dependent spin mixing of electronic states with different relative canting angles. Local
transport properties are sensitive to this effect, as we report an atomistic conductance
anisotropy of up toB20% for magnetic skyrmions in Pd/Fe/Ir(111) thin films. In single
skyrmions, engineering this spin-mixing magnetoresistance could possibly be incorporated in
future magnetic storage technologies.