Phase fluctuations of a Bose-Einstein condensate in low-dimensional geometry

Journal Article · Fri Jul 15 04:00:00 EDT 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.72.013607· OSTI ID:20718399

Kadio, Demascoth ^[1]; Gajda, Mariusz ^[2]; Rzazewski, Kazimierz ^[1]

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1. Center for Theoretical Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland)
2. Institute of Physics, Polish Academy of Sciences, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland) and Faculty of Mathematics and Natural Sciences, Cardinal Stefan Wyszynski University, Aleja Lotnikow 32/46, 02-668 Warsaw (Poland)

We investigate the phase fluctuations of a Bose-Einstein condensate in one- (1D) and three-dimensional (3D) elongated harmonic traps with the help of the numerical simulation using classical field approximation. By calculating the eigenvalues of the one-dimensional single-particle density matrix we show that the phase fluctuations of a Bose-Einstein Condensate in a 1D system are due to the thermal low-energy excitations. We find that the phase fluctuations depend on the temperature as has been predicted [Phys. Rev. Lett. 85, 3745 (2000), Phys. Rev. Lett. 87, 050404 (2001)]. Finally we show that the phase coherence length of a condensate in a harmonic trap depends on the aspect ratio of anisotropy (geometry) of the trap. We determine the border between the 3D and quasi-one-dimensional systems by calculating the phase coherence length of the condensate.

• OSTI ID: 20718399
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 1 Vol. 72; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ANISOTROPY
ASPECT RATIO
BOSE-EINSTEIN CONDENSATION
COHERENCE LENGTH
COMPUTERIZED SIMULATION
DENSITY MATRIX
EIGENFUNCTIONS
EIGENVALUES
EXCITATION
FLUCTUATIONS
GEOMETRY
ONE-DIMENSIONAL CALCULATIONS
THREE-DIMENSIONAL CALCULATIONS
TRAPS