  The influence of an electrical current on the propagation of magnetostatic
surface waves is investigated in a relatively thick (40 nm) permalloy film both
experimentally and theoretically. Contrary to previously studied thinner films
where the dominating effect is the current-induced spin-wave Doppler shift, the
magnetic field generated by the current (Oersted field) is found to induce a
strong non-reciprocal frequency shift which overcompensates the Doppler shift.
The measured current induced frequency shift is in agreement with the developed
theory. The theory relates the sign of of the frequency shift to the spin wave
modal profiles. The good agreement between the experiment and the theory
confirms a recent prediction of a counter-intuitive mode localization for
magnetostatic surface waves in the dipole-exchange regime.
