Gas-to-soliton transition of attractive bosons on the surface of a sphere.
Andrea Tononi (LPTMS)
The many-body physics of condensed matter systems in low-dimensional flat geometries has been the object of an enormous amount of studies in the past. Nowadays, new research possibilities are emerging by considering many-body quantum systems confined on curved manifolds. In systems of ultracold atoms, for instance, the recent experimental advances allow to confine gases of bosonic atoms in curved setups such as ellipsoidal shells. A simple and fundamental model of this geometry, which allows to capture the interplay of spatial curvature and quantum physics in a nontrivial topology, is constituted by a bosonic gas confined on the surface of a sphere. In my talk, I will present preliminary results on this system, analyzing how an attractive zero-range interaction between the particles can induce a crossover from a weakly-interacting gas regime to a localized solitonic state. We believe that this crossover, analyzed through Monte Carlo simulations, mean-field methods and perturbation theory, becomes a first-order phase transition as the number of bosons confined on the sphere tends to infinity.