Phase slip phenomena in superfluid helium

This article describes some recent experiments which demonstrate phenomena, in both superfluid ⁴He and ³He. that can easily be interpreted in terms of the quantum phase dynamics approach of the Josephson-Anderson (JA) equation. In one experiment, a quantized vortex filament performs a stable precession in a cylinder at a frequency given by the JA equation. In other experiments, superflow in submicron apertures exhibits discrete phase slips whose magnitude is quantized in units given by the JA equation. These discrete phase slips provide information on the nucleation processes which lead to the creation of quantized vorticity.