Berlin 2005 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 32: Quantengase I
Q 32.3: Vortrag
Dienstag, 8. März 2005, 11:15–11:30, HU Kinosaal
Noise-correlation spectroscopy of ultracold atoms in optical lattices — •S. Fölling, F. Gerbier, A. Widera, T. Gericke, O. Mandel, and I. Bloch — Johannes Gutenberg Universität Mainz, 55099 Mainz
Ultracold Atoms in the Mott insulating phase inside an optical lattice do not exhibit phase coherence over multiple lattice sites - in strong contrast to the superfluid phase of the lattice. Therefore, the most immediate signature of the Mott insulating state in these systems is the complete disappearance of any macroscopic interference in the atomic cloud after ballistic expansion.
The atom-atom correlation function however shows the opposite behaviour – in the phase-coherent superfluid state the g(2) function should be flat, whereas the atoms from the Fock states of the Mott insulator exhibit Hanbury-Brown/Twiss-type bunching. As proposed in [1] this should lead to sharp peaks in the density-density correlation function in momentum space at even multiples of the lattice recoil momentum. We report on the characterization of such correlations in 87Rb-Mott insulators in an optical lattice.
[1] E. Altman, E. Demler and M. D. Lukin, Phys. Rev. A 70, 013603 (2004)