Coexistence of phase transitions and hysteresis near BEC
Abstract
Multiple phases occurring in a Bose gas with finite-range interaction are investigated. In the vicinity of the onset of Bose-Einstein condensation (BEC) the chemical potential and the pressure show a van-der-Waals like behavior indicating a first-order phase transition although there is no long-range attraction. Furthermore the equation of state becomes multivalued near the BEC transition. For a Hartree-Fock or Popov (Hartree-Fock-Bogoliubov) approximation such a multivalued region can be avoided by the Maxwell construction. For sufficiently weak interaction the multivalued region can also be removed using a many-body \mbox{T-matrix} approximation. However, for strong interactions there remains a multivalued region even for the \mbox{T-matrix} approximation and after the Maxwell construction, what is interpreted as a density hysteresis. This unified treatment of normal and condensed phases becomes possible due to the recently found scheme to eliminate self-interaction in the \mbox{T-matrix} approximation, which allows to calculate properties below and above the critical temperature.
Keywords
Cite
@article{arxiv.1305.5192,
title = {Coexistence of phase transitions and hysteresis near BEC},
author = {M. Männel and K. Morawetz and P. Lipavský},
journal= {arXiv preprint arXiv:1305.5192},
year = {2013}
}
Comments
Phys. Rev. A 87, 053617 (2013) [7 pages]