Finite-temperature properties of quasi-two-dimensional Bose-Einstein condensates
- 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, Vol. 73, Issue 3; Other Information: DOI: 10.1103/PhysRevA.73.033606; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
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