Domain Nucleation and Annihilation in Uniformly Magnetized State under   Current Pulses in Narrow Ferromagnetic Wires
  We investigate the current-driven magnetization dynamics in narrow Permalloy wires by means of Lorentz microscopy and electron holography. Current pulses are found to transform the magnetic structure in the uniformly magnetized state below the Curie temperature. A variety of magnetic states including reversed magnetic domains are randomly obtained in low probability. The dynamics of vortices found in most of observed magnetic states seems to play a key role in triggering the magnetization reversal. 
Yoshihiko Togawa, Takashi Kimura, Ken Harada, Tetsuya Akashi, Tsuyoshi   Matsuda, Akira Tonomura, Yoshichika Otani