Coherence properties of a Bose-Einstein condensate in an optical superlattice
Max Planck-Institute für Physik Komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden, Germany and Department of Physics, A.R.S.D College, University of Delhi (South Campus), New Delhi, 110021, India
Corresponding author: a firstname.lastname@example.org
Revised: 21 June 2007
Published online: 14 November 2007
We study the effect of a one dimensional optical superlattice on the superfluid properties (superfluid fraction, number squeezing, dynamic structure factor) and the quasi-momentum distribution of the Mott-insulator. We show that due to the secondary lattice, there is a decrease in the superfluid fraction and the number fluctuation. The dynamic structure factor which can be measured by Bragg spectroscopy is also suppressed due to the addition of the secondary lattice. The visibility of the interference pattern (the quasi-momentum distribution) of the Mott-insulator is found to decrease due to the presence of the secondary lattice. Our results have important implications in atom interferometry and quantum computation in optical lattices.
PACS: 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations / 03.75.-b – Matter waves / 03.75.Kk – Dynamic properties of condensates; collective and hydrodynamic excitations, superfluid flow
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007