1206.4125 (Yuri Gaididei et al.)

The regular pattern formation in ferromagnetic films nearly saturated by
spin-polarized current    [PDF]

Yuri Gaididei, Oleksii M. Volkov, Volodymyr P. Kravchuk, Denis D. Sheka

Process of the saturation of a thin ferromagnetic film in transverse direction by strong spin-polarized current is studied theoretically. It is shown that the critical current of saturation increases with the sample thickness increasing and it is practically independent on the lateral size of the magnet. For the samples whose thickness is less then the exchange length the saturation current quadratically depends on the thickness, for thicker samples this dependence becomes linear. We show that appearance of stable square vortex-antivortex superlattices (crystals) precedes the saturation. Spatial period of the superlattice weakly decreases with the current increasing. Transition from crystal phase into "fluid" phase occurs with the current decreasing. The micromagnetic simulations confirms our analytical results with a high accuracy.

View original: http://arxiv.org/abs/1206.4125