2008/03/31 by E. Toth, Ana María Rey, A. M. Rey +1 · 1 citation
Chemistry · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum, superfluid, helium dynamics #Spectroscopy and Laser Applications #cond-mat.other
paper · pdf · doi:10.1103/physreva.78.013627
published as Phys. Rev. A 78, 013627 (2008) · 18 pages, 11 figures. To appear in Phys. Rev. A. (few minor changes made and typos fixed)
arxiv created 2008/07/12 · openalex publication_date 2008/07/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper we develop a theoretical description of the correlations between ultracold bosons after free expansion from confinement in an optical lattice. We consider the system evolution during expansion and give criteria for a far-field regime. We develop expressions for first and second order two-point correlations based on a variety of commonly used approximations to the many-body state of the system including Bogoliubov, mean-field decoupling, and particle-hole perturbative solution about the perfect Mott-insulator state. Using these approaches we examine the effects of quantum depletion and pairing on the system correlations. Comparison with the directly calculated correlation functions is used to justify a Gaussian form of our theory from which we develop a general three-dimensional formalism for inhomogeneous lattice systems suitable for numerical calculations of realistic experimental regimes.