Magnetization Dynamics in Nanocontact Current Controlled Oscillators

This work focuses on the magnetization dynamics driven by spin-polarized currents in nonconfined systems when a point-contact geometry is used. We demonstrate that a generalized formulation of the spin-torque efficiency function, which includes space and angular dependences, combined with the usage of abrupt absorbing boundary conditions, which has been found to be suitable to eliminate spin-wave reflection at the computational boundaries, leads to a quantitative agreement between simulations and experimental observations. A study of the properties of spin waves excited close to the threshold clearly indicates the robustness of Slonczewski's prediction. Nevertheless, full-scale investigations reveal the necessity of introducing additional nonlinearities in the equation of motion under the large-angle oscillation regime.