Interaction of phonons at superfluid helium-solid interfaces

Abstract

New method to obtain the interaction Hamiltonian of phonons at superfluid helium-solid interface is proposed in the work. Equations of hydrodynamic variables are obtained in terms of second quantization if helium occupies a half-space. The contributions of all processes to the heat flux from solid to superfluid helium are calculated based on obtained Hamiltonian. The angular distribution of phonons that are emitted by solid are found in different processes. It is shown, that all of exit angles of superfuild helium phonons are allowed. The obtained results are compared with experimental data and with previous theoretical works.

Keywords

• phonon
• angular distribution
• heat flow
• Kapitza gap
• interface