Perturbation of spin-valve nanowire reference layers during domain wall motion induced by nanosecond-long current pulses

The depinning of domain walls from notches in spin-valve (SV) nanowires induced by nanosecond-long current pulses is probed by giant magnetoresistance. The current densities needed to depin domain walls at low field can be so large that significant Joule heating may be observed for pulses even as short as 1 ns. The reference layers in the SV, which are formed from highly stable artificial antiferromagnetic layers, can be so strongly perturbed that the resistance of the SV is no longer a reliable indicator of the domain wall's position. © 2008 American Institute of Physics.