Title:
|
Thermodynamic behavior of a one-dimensional Bose gas at low temperature
|
Author:
|
Rosi, Giulia de; Astrakharchik, Grigori; Stringari, Sandro
|
Other authors:
|
Universitat Politècnica de Catalunya. Departament de Física; Universitat Politècnica de Catalunya. SIMCON - Grup de Recerca de Simulació per Ordinador en Matèria Condensada |
Abstract:
|
We show that the chemical potential of a one-dimensional (1D) interacting Bose gas exhibits a nonmonotonic temperature dependence which is peculiar of superfluids. The effect is a direct consequence of the phononic nature of the excitation spectrum at large wavelengths exhibited by 1D Bose gases. For low temperatures T, we demonstrate that the coefficient in T^2 expansion of the chemical potential is entirely defined by the zero-temperature density dependence of the sound velocity. We calculate that coefficient along the crossover between the Bogoliubov weakly interacting gas and the Tonks-Girardeau gas of impenetrable bosons. Analytic expansions are provided in the asymptotic regimes. The theoretical predictions along the crossover are confirmed by comparison with the exactly solvable Yang-Yang model in which the finite-temperature equation of state is obtained numerically by solving Bethe-ansatz equations. A 1D ring geometry is equivalent to imposing periodic boundary conditions and arising finite-size effects are studied in detail. At T=0 we calculated various thermodynamic functions, including the inelastic structure factor, as a function of the number of atoms, pointing out the occurrence of important deviations from the thermodynamic limit. |
Subject(s):
|
-Àrees temàtiques de la UPC::Física -Thermodynamics -Bose-Einstein gas -Thermodynamic
Bose gas -Termodinàmica -Condensació de Bose-Einstein |
Rights:
|
Attribution-NonCommercial-NoDerivs 3.0 Spain
http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
|
Article - Submitted version Article |
Published by:
|
AMER PHYSICAL SOC
|
Share:
|
|