Time structure of fast domain wall creation by localized fields in a magnetic nanowire

We have investigated the generation of magnetic domain walls by nanosecond magnetic field pulses of a strip line. Domain wall creation is sensitive to an externally applied field concerning wall type and threshold amplitudes. The domain wall creation is stochastic similar to domain wall depinning. In the experiment reliable domain wall generation require up to 8 ns long pulses at the threshold field amplitude. The required pulse length can be reduced by higher field amplitudes. Time-resolved measurements and micromagnetic simulations show that the domain wall is generated within three nanoseconds. The creation proceeds via vortex core formation under the strip line. (C) 2013 AIP Publishing LLC.