Nonperturbative dynamical manybody theory of a BoseEinstein condensate
Abstract
A dynamical manybody theory is presented which systematically extends beyond meanfield and perturbative quantumfield theoretical procedures. It allows us to study the dynamics of strongly interacting quantumdegenerate atomic gases. The nonperturbative approximation scheme is based on a systematic expansion of the twoparticle irreducible effective action in powers of the inverse number of field components. This yields dynamic equations which contain direct scattering, memory, and 'offshell' effects that are not captured by the GrossPitaevskii equation. This is relevant to account for the dynamics of, e.g., strongly interacting quantum gases atoms near a scattering resonance, or of onedimensional Bose gases in the TonksGirardeau regime. We apply the theory to a homogeneous ultracold Bose gas in one spatial dimension. Considering the time evolution of an initial state far from equilibrium we show that it quickly evolves to a nonequilibrium quasistationary state and discuss the possibility to attribute an effective temperature to it. The approach to thermal equilibrium is found to be extremely slow.
 Authors:
 Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)
 Publication Date:
 OSTI Identifier:
 20786341
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. A; Journal Volume: 72; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevA.72.063604; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 74 ATOMIC AND MOLECULAR PHYSICS; ACTION INTEGRAL; APPROXIMATIONS; ATOMS; BOSEEINSTEIN CONDENSATION; BOSEEINSTEIN GAS; MANYBODY PROBLEM; MEANFIELD THEORY; ONEDIMENSIONAL CALCULATIONS; RESONANCE; SCATTERING; THERMAL EQUILIBRIUM
Citation Formats
Gasenzer, Thomas, Berges, Juergen, Schmidt, Michael G., and Seco, Marcos. Nonperturbative dynamical manybody theory of a BoseEinstein condensate. United States: N. p., 2005.
Web. doi:10.1103/PHYSREVA.72.0.
Gasenzer, Thomas, Berges, Juergen, Schmidt, Michael G., & Seco, Marcos. Nonperturbative dynamical manybody theory of a BoseEinstein condensate. United States. doi:10.1103/PHYSREVA.72.0.
Gasenzer, Thomas, Berges, Juergen, Schmidt, Michael G., and Seco, Marcos. Thu .
"Nonperturbative dynamical manybody theory of a BoseEinstein condensate". United States.
doi:10.1103/PHYSREVA.72.0.
@article{osti_20786341,
title = {Nonperturbative dynamical manybody theory of a BoseEinstein condensate},
author = {Gasenzer, Thomas and Berges, Juergen and Schmidt, Michael G. and Seco, Marcos},
abstractNote = {A dynamical manybody theory is presented which systematically extends beyond meanfield and perturbative quantumfield theoretical procedures. It allows us to study the dynamics of strongly interacting quantumdegenerate atomic gases. The nonperturbative approximation scheme is based on a systematic expansion of the twoparticle irreducible effective action in powers of the inverse number of field components. This yields dynamic equations which contain direct scattering, memory, and 'offshell' effects that are not captured by the GrossPitaevskii equation. This is relevant to account for the dynamics of, e.g., strongly interacting quantum gases atoms near a scattering resonance, or of onedimensional Bose gases in the TonksGirardeau regime. We apply the theory to a homogeneous ultracold Bose gas in one spatial dimension. Considering the time evolution of an initial state far from equilibrium we show that it quickly evolves to a nonequilibrium quasistationary state and discuss the possibility to attribute an effective temperature to it. The approach to thermal equilibrium is found to be extremely slow.},
doi = {10.1103/PHYSREVA.72.0},
journal = {Physical Review. A},
number = 6,
volume = 72,
place = {United States},
year = {Thu Dec 15 00:00:00 EST 2005},
month = {Thu Dec 15 00:00:00 EST 2005}
}

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