Nonlinear dynamics of magnetic nanodots
Yuri Gaididei,
Bogolyubov Institute for Theoretical Physics (Kiev, Ucrania)
Jueves 26 de junio 2008
The control of magnetic nonlinear nanostructures using magnetic
fields and electric current is of special interest for applications
in spintronics. A prospective candidate for this program is the vortex
state nanodot, which provides high density storage and high speed
magnetic random access memory. I will present an overview of statics
and dynamics of magnetic vortices in nanomagnets. In particular,
I describe the structure of vortices and effects of internal modes
in connection with the vortex dynamics. The special interest will
be concentrated on the problem of the vortex dynamics under the
influence of ac magnetic fields and spin-polarized electrical
currents. It will be shown that the mechanism of core magnetization
switching is quite general. It includes a creation of an intermediate
vortex-vortex-antivortex state with subsequent annihilation of the
original vortex and new-born antivortex. A simple analytical picture
of such phenomena is proposed.