Magnetoresistance in a lithography defined single constrained domain wall spin-valve

摘要

We have measured domain wall magnetoresistance in a single lithographically constrained domain wall. An H-shaped Ni nanobridge was fabricated by e-beam lithography with the two sides being single magnetic domains showing independent magnetic switching. The connection between the sides constrains the domain wall when the sides line up antiparallel. The magnetoresistance curve clearly identifies the magnetic configurations that are expected from a spin-valvelike structure. The value of the magnetoresistance at room temperature is around 0.1% or 0.4 Ω. This value is shown to be in agreement with a theoretical formulation based on spin accumulation. Micromagnetic simulations show that it is possible to reduce the size of the domain wall further by shortening the length of the bridge.