Vortices in superfluid BEC's

Weakly-interacting Bose-Einstein condensates exhibit superfluid behavior, where the condensed atoms flow collectively without experiencing viscous dissipation or drag. Superfluid flow is sustained at flow fields below a critical value, known as the Landau criterion. When the flow speed exceeds this critical value, phonon excitations or vortices are generated, inducing a local drag and energy dissipation.

When a stirring potential is both sufficiently large and moves at a high enough speed, it sheds quantum vortices analogous to a vortex wake behind the wings of a flying airplane. However, a quantum vortex carries a quantised angular momentum and has localised stable core masking the topology singularity in the condensate phase. Quantum vortices generate persistent superfluid vorticity and through vortex clusterings sustain quantum turbulence with energy cascades across scales.