We consider the nonlinear interaction of zero sound with the collective modes of the order parameter in superfluid 3He-B. Starting from the quasi-classical theory of superfluid 3He, we derive equations describing a three-wave resonance between the J = 2+ (real squashing) modes and two zero-sound phonons at different frequencies. We point out similarities between the nonlinear excitation of collective modes of the 3He-B order parameter and related effects in nonlinear optical systems. In particular, it should be possible to observe stimulated Raman scattering of zero sound and two-phonon absorption by the 2+ mode.
ASJC Scopus subject areas
- Physics and Astronomy(all)