Heidelberg 2015 – wissenschaftliches Programm
Q 15.33: Poster
Montag, 23. März 2015, 17:00–19:00, C/Foyer
Quasi-Condensation and Superfluidity in a Ring Trap — Hansjörg Polster and •Carsten Henkel — University of Potsdam, Germany
Low-dimensional Bose gases suffer from large phase fluctuations that prevent the formation of a proper condensate as defined by Penrose and Onsager. We study a one-dimensional, phase-fluctuating gas in the cross-over region between the ideal gas and the quasi-condensate (weak interactions). Correlation functions of any order are found by mapping the quantum field theory to a random walk in the complex plane, making a classical field approximation . We discuss in particular full distribution functions for the atomic density, including the formation of pairs and clusters at the onset of quasi-condensation. Currently we investigate the distribution function of the total particle current in a rotating ring trap  which provides insight into the superfluid behaviour of the gas.
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