Atom-atom correlations in time-of-flight imaging of ultracold bosons in optical lattices

Journal Article · Tue Nov 15 00:00:00 EST 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.84.053613· OSTI ID:22093594

Zaleski, T. A.; Kopec, T. K. ^[1]

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1. Institute of Low Temperature and Structure Research, Polish Academy of Sciences, POB 1410, 50-950 Wroclaw 2 (Poland)

We study the spatial correlations of strongly interacting bosons in a ground state, confined in a two-dimensional square and a three-dimensional cubic lattice. Using the combined Bogoliubov method and the quantum rotor approach, we map the Hamiltonian of strongly interacting bosons onto U(1) phase action in order to calculate the atom-atom correlations' decay along the principal axis and a diagonal of the lattice-plane direction as a function of distance. Lower tunneling rates lead to quicker decays of the correlations, whose character becomes exponential. Finally, correlation functions allow us to calculate quantities that are directly bound to experimental outcomes, namely time-of-flight absorption images and resulting visibility. Our results contain all the characteristic features present in experimental data (transition from Mott insulating blob to superfluid peaks, etc.), emphasizing the usability of the proposed approach.

• OSTI ID: 22093594
• Journal Information: Physical Review. A, Vol. 84, Issue 5; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
74 ATOMIC AND MOLECULAR PHYSICS
ABSORPTION
ATOMS
BOSONS
CORRELATION FUNCTIONS
CORRELATIONS
CUBIC LATTICES
GROUND STATES
HAMILTONIANS
ROTORS
SUPERFLUIDITY
THREE-DIMENSIONAL CALCULATIONS
TIME-OF-FLIGHT METHOD
TUNNEL EFFECT
TWO-DIMENSIONAL CALCULATIONS
U-1 GROUPS