Capillary propagation of sound and anomalous Kapitsa jump at the boundary between solid and liquid helium
Marchenko V.I., Parshin A.Ya.
It is shown that the probability of sound propagation across the quantum boundary between liquid and solid helium at Τ = 0 is proportional to the square of the frequency. The Kapitsa jump at such a boundary depends, therefore, on the temperature according to a Τ ~5 law.