  Experimental results of rectification of a constant wave radio frequency (RF)
current flowing in a single-layered ferromagnetic wire are presented. We show
that a detailed external magnetic field dependence of the RF current induced a
direct-current voltage spectrum. The mechanism of the rectification is
discussed in a term of the spin transfer torque, and the rectification is
closely related to resonant spin wave excitation with the assistant of the
spin-polarized RF current. The micromagnetic simulation taking into account the
spin transfer torque provides strong evidence which supports the generation of
spin wave excitation by the RF current.
