title: Nonlinear domain-wall velocity enhancement by spin-polarized electric current.
abstract: The interaction between a dc spin-polarized electric current and a magnetic domain wall in a Permalloy nanowire was studied by high-bandwidth scanning Kerr polarimetry. The full functional dependence of wall velocity on electric current and magnetic field is presented. With the pinning potential nulled by a field, current-induced velocity enhancements exceeded 35 m/s at a current density of approximately 6 x 10(11) A/m(2). This large enhancement, more than 10 times that found in pinning-dominated experiments, results in part from an interaction that is nonlinear in current and independent of current direction.
authors.affiliation: Department of Physics, The University of Texas at Austin, Austin, TX 78712-0264, USA. gbeach@physics.utexas.edu
authors.forename: G S D
authors.initials: GS
authors.lastname: Beach
authors.forename: C
authors.initials: C
authors.lastname: Knutson
authors.forename: C
authors.initials: C
authors.lastname: Nistor
authors.forename: M
authors.initials: M
authors.lastname: Tsoi
authors.forename: J L
authors.initials: JL
authors.lastname: Erskine