PARALLEL PUMP SPIN-WAVE INSTABILITY THRESHOLD IN THIN FERROMAGNETIC-FILMS

A rigorous theory of parallel pump instability threshold of spin waves in ferromagnetic films is developed. Dipole and exchange interactions , the dipole-dipole hybridization of spin wave branches, and the magne tocrystalline and induced anisotropies are taken into account. Express ions for the parallel pump instability threshold are obtained in gener al form which can be used to calculate the threshold of a single ferro magnetic layer or a multilayered structure containing an arbitrary num ber of ferromagnetic films. The influences of the dipole-dipole hybrid ization of parametrically generated spin waves and of their nonrecipro cal propagation properties on the threshold are discussed.