Quantum Monte Carlo study of quasi-one-dimensional Bose gases
G. E. Astrakharchik, D Blume, S Giorgini +1 more
We study the behaviour of quasi-one-dimensional (quasi-1D) Bose gases by Monte Carlo techniques, i.e. by the variational Monte Carlo, the diffusion Monte Carlo and the fixed-node diffusion Monte Carlo techniques. Our calculations confirm and extend our results of an earlier study (Astrakharchik et al 2003 Preprint cond-mat/0308585). We find that a quasi-1D Bose gas (i) is well described by a 1D model Hamiltonian with contact interactions and renormalized coupling constant; (ii) reaches the Tonks–Girardeau regime for a critical value of the 3D scattering length a 3D ; (iii) enters a unitary regime for | a 3D | → ∞ , where the properties of the gas are independent of a 3D and are similar to those of a 1D gas of hard-rods and (iv) becomes unstable against cluster formation for a critical value of the 1D gas parameter. The accuracy and implications of our results are discussed in detail.
arXiv:cond-mat/0310749•Journal of Physics B Atomic Molecular and Optical Physics•Mar 24, 2004•23 citations