A Formula for Determining the Wave Vector Orientation at Which the Amplitude of the Magnetic Potential of a Backward Spin Wave Has an Extremum on the Surface of a Ferrite Film

Abstract

A magnetostatic approximation is used to derive a formula for the wave vector orientation at which a nonreciprocal backward spin wave is effectively excited in a tangentially magnetized ferrite plate. The amplitude of the magnetic potential of the wave has an extremum on one of the surfaces of the plate for a given orientation of the wave vector, but this amplitude is low on the other surface of the plate.