Vertical stack of Co nanorings with current-perpendicular-to-plane giant magnetoresistance: Experiment and micromagnetic simulation

摘要

Vertical stacks of two Co rings with deep submicron lateral sizes and different thicknesses are fabricated and studied. The experimental results suggest the existence of a metastable domain wall structure revealed by the micromagnetics simulation. The technologically important vortex-vortex switching is found dominated by the annular Oersted field of perpendicularly injected dc, but also significantly affected by the spin-transfer torque. The efficiency of the spin-transfer torque and the switching process are discussed.