Thermodynamics of a multicomponent-atom sample in a tightly compressed atom trap

Abstract

We use classical statistical mechanics and thermodynamics to describe the response of a trapped multispecies atomic sample to a local deformation in the confining potential. An adiabatic deformation may not only increase the peak phase-space density, but also lower the temperature and spin-polarize the atoms.

Optimized production of large Bose-Einstein condensates

“…The right side approximations in equations (1) hold when the key parameter η V e −∆/T f ≈ η V e η d is small compared to 1. As indicated by the figures 2 and 6, the analytical equations (1) inspired by the model described in reference [40] are found to be qualitatively correct and might be used as a first guide toward the optimized strategy.…”

“…In order to study the loading of the dimple trap we will first deduce thermodynamics quantities (such as the atom number N and the temperature T ) from standard thermodynamics equations [40]. Here, we will safely neglect gravity (see figure 1).…”

“…Our numerical results are given in figure 2 (see also the top part of figure 6) where they are compared with the one dimensional quadratic + two dimensional box model developed in reference [40] and that, after small calculations, lead in our case to the following formulas:…”

“…with a slow change in laser power and the system evolves with constant entropy S f = S i , or in a sudden way with constant energy. Up to now, most of the experimental and theoretical works were focused on the adiabatic process [18,40,41]. However, it is faster to suddenly apply a small dimple trap and the difference in the final temperature (see figure 2) or atom number is marginal compared to the adiabatic loading process.…”