Optical generation of the first and second sounds in superfluid 3He–4He solutions

Abstract

An optical method of generation of the first and second sounds in superfluid 3He–4He solutions is proposed. The method is based on illumination by amplitude-modulated laser beam with wavelength corresponding to a region of absorption. Numerical calculations of pressure and temperature as a function of time are carried out. It was found that the presence of 3He isotopes in the solution provides strong coupling between these parameters. As a result, the waves of the first sound involve oscillations of the temperature, while the waves of the second sound involve oscillations of the pressure.