Stuttgart 2012 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 40: Poster: Ultra-cold atoms, ions and BEC
A 40.18: Poster
Donnerstag, 15. März 2012, 16:30–19:00, Poster.V
Thermodynamic properties of 2D dipolar gases — •Alexey Filinov und Michael Bonitz — Institute for Theoretical Physics and Astrophysics, Christian-Albrechts-Universität, Kiel, Germany
We perform the path integral Monte Carlo simulations to study the finite temperature properties of interacting dipolar Bose gas in two-dimensional geometry in the grand canonical ensemble. We investigate the equation of state, the temperature dependence of the superfluid fraction, the quasi-condensate n0, the momentum distribution and the isothermal compressibility κ for temperatures above and below the Berezinskii-Kosterlitz-Thouless crossover to the superfluid phase. The increase in the occupation of the zero-momentum state n0 leads to suppression of the density fluctuations and a non-monotonic behavior of the compressibility κ in the presuperfluid regime. We also analyse dependence of the phonon-maxon-roton excitation branch and the dynamic structure factor on the chemical potential (or density) and temperature. The spectrum of longitudinal collective modes is reconstructed from the imaginary time density-density correlation function.