Finite-temperature properties of quasi-two-dimensional Bose-Einstein condensates

Journal Article · Wed Mar 15 04:00:00 EST 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.73.0· OSTI ID:20786964

Nho, Kwangsik; Landau, D P ^[1]

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1. Center for Simulational Physics, University of Georgia, Athens, Georgia 30602 (United States)

Using the finite-temperature path integral Monte Carlo method, we investigate dilute, trapped Bose gases in a quasi-two-dimensional (quasi-2D) geometry. The quantum particles have short-range, s-wave interactions described by a hard-sphere potential whose core radius equals its corresponding scattering length. The effect of both the temperature and the interparticle interaction on the equilibrium properties such as the total energy, the density profile, and the superfluid fraction is discussed. We compare our accurate results with both the semiclassical approximation and the exact results of an ideal Bose gas. Our results show that for repulsive interactions (i) the minimum value of the aspect ratio, where the system starts to behave quasi-2D, increases as the two-body interaction strength increases; (ii) the superfluid fraction for a quasi-two-dimensionally Bose gas is distinctly different from that for both a quasi-1D Bose gas and a true 3D system, i.e., the superfluid fraction for a quasi-2D Bose gas decreases faster than that for a quasi-1D system and a true 3D system with increasing temperature, and shows a stronger dependence on the interaction strength; (iii) the superfluid fraction for a quasi-2D Bose gas lies well below the values calculated from the semiclassical approximation; and (iv) the Kosterlitz-Thouless transition temperature decreases as the strength of the interaction increases.

• OSTI ID: 20786964
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 73; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
BOSE-EINSTEIN CONDENSATION
BOSE-EINSTEIN GAS
COMPARATIVE EVALUATIONS
GEOMETRY
MONTE CARLO METHOD
PATH INTEGRALS
POTENTIALS
S WAVES
SCATTERING LENGTHS
SEMICLASSICAL APPROXIMATION
SUPERFLUIDITY
TRANSITION TEMPERATURE
TRAPPING
TWO-BODY PROBLEM
TWO-DIMENSIONAL CALCULATIONS