Multi-step Bose–Einstein condensation of trapped ideal Bose gases

Yvan Castin

Wenji Deng, Typeset Using Revtex

Abstract: The Phenomenon of multi-step Bose-Einstein condensation (BEC) of a finite number of non-interacting bosons in anisotropic traps has been demonstrated by studing the populations on eight subsets of states. The cusp in the specific heat is found to be associated with the crossover between subsets of states involving Bose functions gn(z) of different classes, as specified by their behaviour at z = 1.

Jun’ichi Ieda, Takeya Tsurumi, Miki Wadati

Bose–Einstein condensation (BEC) is studied for ideal boson gases with a wide class of the dispersion relations. A criterion of the BEC, the transition temperature and a fraction of the condensate are calculated under the appropriate thermodynamic limits. The correspondence between the dispersion relation (spectrum) and the trap potential is shown. This gives the criterion for the trap shape and the dimensionality of the system.

Yi Xue-Xi, Haijun Wang, Chang-Pu Sun

Bose–Einstein Condensation (BEC) of both the ideal and the weakly inter-acting cold alkali gases confined by anisotropic harmonic oscillator poten-tials is investigated in this paper. It is shown that the transition point is shifted towards lower temperatures because of the trapped potentials, and the specific heat below the transition point is no longer proportional to T 3/2 . Expressions of modified condensation temperature, internal energy and the specific heat are derived for the ideal trapped gases explicitly. Moreover, the effect of interactions among the atoms on the transition temperature is also given and discussed.

Lawrence J. Landau, Ivan F. Wilde