High domain wall velocity at zero magnetic field induced by low current densities in spin-valve nanostripes

TL;DR

This study demonstrates high domain wall velocities exceeding 150 m/s at zero magnetic field in spin-valve nanostripes driven by low current densities, highlighting their potential for domain wall device applications.

Contribution

It reveals that spin-valve nanostripes can achieve high domain wall velocities at low current densities, with vertical spin currents possibly explaining this efficiency.

Findings

Domain wall velocities >150 m/s at low current densities

High velocities occur despite pinning sites

Vertical spin currents may enhance domain wall motion

Abstract

Current-induced magnetic domain wall motion at zero magnetic field is observed in the permalloy layer of a spin-valve-based nanostripe using photoemission electron microscopy. The domain wall movement is hampered by pinning sites, but in between them high domain wall velocities (exceeding 150 m/s) are obtained for current densities well below $10^{12} \unit{A/m^2}$, suggesting that these trilayer systems are promising for applications in domain wall devices in case of well controlled pinning positions. Vertical spin currents in these structures provide a potential explanation for the increase in domain wall velocity at low current densities.