The Department of Physics at the University of Illinois at Urbana-Champaign

Phase slips control dissipation in many bosonic systems, determining the critical velocity of superfluid helium and the generation of resistance in thin superconducting wires. As reported in Nature today, researchers in Brian DeMarco's group have demonstrated that phase slips can lead to dissipation in a clean and well-characterized Bose–Hubbard system by experimentally studying the transport of ultracold atoms trapped in an optical lattice. Their results clarify the role of phase slips in superfluid systems and may elucidate the source of metallic phases observed in thin films.

This work was supported by the National Science Foundation, the Office of Naval Research, and the University of Illinois Research Board. The conclusions presented are those of the authors and not necessarily of the funding agencies.