Vortices and other topological defects in non-equilibrium phase transitions of superfluid He

Rapidly evolving non-equilibrium phenomena, associated with phase transitions from meta-stable states, provide examples of most complex dynamics. Condensed matter many-particle quantum systems, which are described in terms of a coherent quantum field, are a particularly useful environment for such studies. Among them, the ³He superfluids display the largest variety of topological defects of different dimensionality and structure, owing to the large degree of freedom in the rearrangement of their multi-component p-wave order parameter field. A few measurements exist which monitor the non-equilibrium phase transition dynamics and display defect formation.