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Q: Fachverband Quantenoptik und Photonik
Q 17: Quantengase: Bosonen Dynamik / Disorder
Q 17.4: Talk
Tuesday, March 3, 2009, 11:15–11:30, VMP 6 HS-A
Comparison of stochastic theories for the dynamics of Bose gases — Stuart Cockburn1, •Carsten Henkel2, Antonio Negretti3, and Nikolaos Proukakis1 — 1School of Mathematics and Statistics, Newcastle University, United Kingdom — 2Institut für Physik und Astronomie, Universität Potsdam, Germany — 3Institut für Quanten-Informationsverarbeitung, Universität Ulm, Germany
Theoretical modelling of ultracold Bose gases at finite temperature
is based on a variety of
different techniques, and the precise relation between these approaches is
not yet established [1]. In this work, we compare two numerical simulation
schemes that combine propagation according to the
Gross-Pitaevskii equation with different initial states:
the number-conserving Bogoliubov method [2] and the stochastic
Gross-Pitaevskii equation [3,4]. In the latter method, the state is prepared
by coupling a heat bath to the atomic quantum field. We compare the initial
data, looking at diagnostics such as condensate statistics.
Dynamical observables after releasing the initial state at different
temperatures are analyzed: we focus on the cases that the heat bath
is removed [5] or not.
[1] N.P. Proukakis and B. Jackson, J. Phys. B 41, 203002 (2008).
[2] Y. Castin and R. Dum, Phys. Rev. A 57, 3008 (1998); A. Sinatra, C.
Lobo and Y. Castin, J. Phys. B 35, 3599 (2002).
[3] H.T.C. Stoof, J. Low Temp. Phys. 114, 11 (1999).
[4] C.W. Gardiner and M.J. Davis, J. Phys. B 36, 4731 (2003).
[5] N.P. Proukakis, J. Schmiedmayer and H.T.C. Stoof, Phys. Rev. A 73,
053603 (2006).