Transverse acoustic impedance of superfluid 3He–B Original Research Article

A microscopic theory of transverse acoustic impedance of the B phase of superfluid 3He is presented. We calculate the stress tensor of superfluid 3He–B as a response to the oscillating rough wall. For that purpose, we extend a quasi-classical theory of the rough wall effects based on the random S-matrix model to time dependent problem. We show that the structures in the temperature dependence found in the experiments of transverse acoustic impedance can be related to the excitation of surface bound states which are characteristic surface effects in anisotropic paring Fermi superfluids.