Spin dynamics in point contacts to single ferromagnetic films
  Excitation of magnons or spin-waves driven by nominally unpolarized transport currents in point contacts of normal and ferromagnetic metals is probed by irradiating the contacts with microwaves. Two characteristic dynamic effects are observed: a rectification of off-resonance microwave current by spin-wave nonlinearities in the point contact conductance, and a resonant stimulation of spin-wave modes in the nano-contact core by the microwave field. These observations provide a direct evidence that the magnetoconductance effects observed are due to GHz spin dynamics at the ferromagnetic interface driven by the spin transfer torque effect of the transport current. 
O. P. Balkashin, V. V. Fisun, I. K. Yanson, L. Yu. Triputen, A.   Konovalenko, and V. Korenivski