Spin-current-induced high-frequency magnetisation rotations and microwave oscillations in magnetic nanodevices

In the paper, the authors first review the structural and functional characteristics of magnetic nanodevices where magnetisation rotations and microwave oscillations are induced by DC electrical currents due to the spin-transfer torque effect. A comparison is made between devices with different structures. Micromagnetic simulations based on the modified Landau-Lifshitz-Gilbert equation are carried out in detail on one of the structures. The study shows that the spin-polarised direct current drives the inhomogeneous magnetisation configuration to rotate in the constrained square magnet structure. Magnetisation configurations and dynamics depend on the input current density and the structure dimension.