Theory of correlations between ultra-cold bosons released from an optical lattice
arXiv:0803.2922 · doi:10.1103/PhysRevA.78.013627
Abstract
In this paper we develop a theoretical description of the correlations between ultra-cold 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, meanfield 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.
18 pages, 11 figures. To appear in Phys. Rev. A. (few minor changes made and typos fixed)
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Cited by in corpus (6)
- Dynamics and statistical mechanics of ultra-cold Bose gases using c-field techniques
- Expansion of a quantum gas released from an optical lattice
- Free expansion of a Lieb-Liniger gas: Asymptotic form of the wave functions
- Critical properties of a trapped interacting Bose gas
- Momentum distribution of a freely expanding Lieb-Liniger gas
- Unconventional quantum phases of lattice bosonic mixtures