Phase diagram for interacting Bose gases
Abstract
We propose a new form of the inversion method in terms of a selfenergy expansion to access the phase diagram of the Bose-Einstein transition. The dependence of the critical temperature on the interaction parameter is calculated. This is discussed with the help of a new condition for Bose-Einstein condensation in interacting systems which follows from the pole of the T-matrix in the same way as from the divergence of the medium-dependent scattering length. A many-body approximation consisting of screened ladder diagrams is proposed which describes the Monte Carlo data more appropriately. The specific results are that a non-selfconsistent T-matrix leads to a linear coefficient in leading order of 4.7, the screened ladder approximation to 2.3, and the selfconsistent T-matrix due to the effective mass to a coefficient of 1.3 close to the Monte Carlo data.
Cite
@article{arxiv.cond-mat/0701280,
title = {Phase diagram for interacting Bose gases},
author = {K. Morawetz and M. Maennel and M. Schreiber},
journal= {arXiv preprint arXiv:cond-mat/0701280},
year = {2009}
}