Switching field modulation of a nanomagnet by resonant microwave spin torque

We report on the effect of a low amplitude microwave current on the switching field of magnetic layers in a 40 nm diameter pseudo-spin valve grown by template synthesis. We show a frequency dependence at room temperature reflecting the dynamic behavior of the switching process. This is confirmed by numerical calculation of the LandauLifschitzGilbert equation including Slonczewski Spin Transfer Torque term within a macrospin approximation. The possibility to modulate the switching fields of a nanomagnet with microwave currents offers an alternative to the magnetic switching assisted by microwave magnetic field. (C) 2010 Elsevier B.V. All rights reserved.