Effect of spin-polarized electric current on spin-wave radiation by spin-valve nanocontacts

Using a spatially resolved microfocus Brillouin light scattering technique with spatial resolution of 250nm, the authors have studied radiation of spin waves by a spin-valve nanocontact into a continuous underlying magnetic film. They have found that a spin-polarized electric current flowing through the contact affects the intensity of radiated spin waves. They show that for one of the directions of the current, the spin-wave intensity is noticeably increased, whereas for the other direction, spin waves are suppressed. They associate the findings with an amplification of spin waves due to spin-torque-transfer phenomena.