%0 Journal Article
%T Collisional de-excitation in a quasi-2D degenerate Bose gas
%A I. B. Spielman
%A P. R. Johnson
%A J. H. Huckans
%A C. D. Fertig
%A S. L. Rolston
%A W. D. Phillips
%A J. V. Porto
%J Physics
%D 2005
%I arXiv
%R 10.1103/PhysRevA.73.020702
%X We separate a Bose-Einstein condensate into an array of 2D sheets using a 1D optical lattice, and then excite quantized vibrational motion in the direction normal to the sheets. Collisions between atoms induce vibrational de-excitation, transferring the large excitation energy into back-to-back outgoing atoms, imaged as rings in the 2D plane. The ring diameters correspond to vibrational energy level differences, and edge-on imaging allows identification of the final vibrational states. Time dependence of these data provides a nearly complete characterization of the decay process including the energies, populations, and lifetimes of the lowest two excited vibrational levels. The measured decay rates represent a suppression of collisional de-excitation due to the reduced dimensionality, a matter wave analog to inhibited spontaneous emission.
%U http://arxiv.org/abs/cond-mat/0509079v1