2000/04/27 by Magdalena A. Zaluska-Kotur, Magdalena A. Załuska–Kotur, Zaluska-Kotur, Magdalena A. +7
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Soft Condensed Matter (cond-mat.soft) #Strong Light-Matter Interactions #cond-mat.soft
paper · pdf · doi:10.48550/arxiv.cond-mat/0004469
10 pages, 2 figures
arxiv created 2000/04/27 · openalex publication_date 2000/04/27 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study a system of trapped bosonic particles interacting by model harmonic forces. Our model allows for detailed examination of the notion of an order parameter (a condensate wave function). By decomposing a single particle density matrix into coherent eigenmodes we study an effect of interaction on the condensate. We show that sufficiently strong interactions cause that the condensate disappears even if the whole system is in its lowest energy state. In the second part of our paper we discuss the validity of the Bogoliubov approximation by comparing its predictions with results inferred from the exactl y soluble model. In particular we examine an energy spectrum, occupation, and fluctuations of the condensate. We conclude that Bogoliubov approach gives quite accurate description of the system in the limit of weak interactions.