Ultracold Bosons in 1D: from Bose-Einstein condensateto Tonks-Girardeau gas

Abstract

We consider an ultracold atomic gas trapped in a one-dimensional harmonic oscillator potential. We study the transition from a Bose-Einstein condensate, in the small atom-atom interaction limit, to a strongly interacting Tonks-Girardeau gas, as the interaction is varied from zero to large values. The response of the system against a monopolar perturbation is characterized by the moments of the dynamic structure function. The calculations have been done by direct diagonalization of the second quantized many-body Hamiltonian in a truncated Fock space. The corresponding virial theorem for the many-body states has been employed to cross-check the validity of our numerical techniques