title: Vortex polarity switching by a spin-polarized current.
abstract: The spin-transfer effect is investigated for the vortex state of a magnetic nanodot. A spin current is shown to act similarly to an effective magnetic field perpendicular to the nanodot. Then a vortex with magnetization (polarity) parallel to the current polarization is energetically favorable. Following a simple energy analysis and using direct spin-lattice simulations, we predict the polarity switching of a vortex. For magnetic storage devices, an electric current is more effective to switch the polarity of a vortex in a nanodot than the magnetic field.
authors.affiliation: Laboratoire de Mathématiques, INSA de Rouen, B.P. 8, 76131 Mont-Saint-Aignan cedex, France. caputo@insa-rouen.fr
authors.forename: Jean-Guy
authors.initials: JG
authors.lastname: Caputo
authors.forename: Yuri
authors.initials: Y
authors.lastname: Gaididei
authors.forename: Franz G
authors.initials: FG
authors.lastname: Mertens
authors.forename: Denis D
authors.initials: DD
authors.lastname: Sheka