We have studied dissipative phase-slip events in the oscillatory superflow of through two different orifices of submicron size. The dissipation events are found to be caused by the phase difference across the orifice changing by 2πn, where the slip integer n depends on the orifice geometry, flow direction, and temperature. The temperature dependence of the phase-slip critical velocity indicates that surface microstructure determines the magnitude of relevant energy barriers.
- Received 18 February 1992
- Published in the issue dated 27 April 1992
© 1992 The American Physical Society