Anna Minguzzi - "Interacting bosons on a ring with a gauge field"
We consider an interacting one-dimensional Bose gas on a ring. The gas is subjected to a rotating barrier potential, which induces an artificial U(1) gauge field and a persistent current flow on the ring. We study the ground state and the lower-excited states of the gas. We show that it is possible to realize macroscopic superpositions of current states by suitably tuning the gauge field, the barrier and interaction strength. We also find that, at intermediate interactions, the persistent current amplitude is maximal, due to a subtle interplay of effects due to the barrier, interactions and quantum fluctuations. We finally show that barrier renormalization is a very general property, also affecting other dynamical properties, eg the frequency of the collective modes for a Bose gas in a split trap.
