Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
In agreement with the theory of phase rigidity in superfluids, simulations of repulsive Bose Einstein condensates (BECs) in one and two dimensions show that shocking a condensate causes it to break up into domains of constant phase. The size of the phase domains is inversely proportional to the strength of the initial shock, so that for strong shocks structure forms on a scale smaller than a healing length. In a two dimensional rectangular billiard a strong shock at an oblique angle results in a chaotic wave function with a density pattern similar to laser speckle. Speckle patterns do not normally occur in two dimensions, since they result from a spread in wave vectors due to the projection of three dimensional monochromatic light onto a two dimensional screen. In the two dimensional BEC dispersion due to the non-linearity mimicks this effect, giving rise to chaos even in an integrable billiard. Using a chaotic billiard enhances the effect.