Magnetic Helix in a Multilayer Ferromagnetic Nanoparticle and Its Rotation Induced by an Electric Current

The dynamics of the magnetization induced by an electric current flowing in a multilayer nanoparticle is studied theoretically. A region of the parameters where the coherent rotation of a magnetic helix, which is formed in this system due to the magnetostatic interaction of ferromagnetic layers, has been determined analytically. Estimates indicate that the predicted nonlinear oscillation mode of the magnetization can be observed experimentally.