Jean-Guy Caputo, Yuri Gaididei, Franz G. Mertens, Denis D. Sheka,
Phys. Rev. Lett. 98, 056604 (2007), 10.1103/PhysRevLett.98.056604
4 pages, 3 figures
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.
Switching picture from numerical simulations on a square lattice with circular boundary.
|Anisotropy coefficient||0.03 a|
|Degree of spin polarization||0.25|