Melting by sound in solid

Abstract We observed the melting of solid 4 He in a superfluid when sound waves were injected to its rough surface at 1.2 K . A single crystal was grown between two transducers and ultrasound pulses were applied normally to the solid–liquid interface from the solid or liquid side. Amount of melting was on the same order in both cases. We measured the amount of melting precisely by changing the sound power and the number of pulses. We also proposed the possible mechanism of the sound induced melting of solid 4 He .