Bose-Einstine condensation in a dilute gas: Measurement of energy and ground state occupation
J R. Ensher, Deborah S. Jin, M R. Matthews, C E. Wieman, Eric A. Cornell
We measure the ground state occupation and energy of a dilute Bose gas as a function of temperature. 87Rb atoms are collected in an optical trap, loaded into a purely magnetic trap, and then evaporated cooled through the Bose-Einstein condensation phase transition. The ground state fraction shows good agreement with the predictions for an ideal Bose gas in a 3-d harmonic potential. The measured transition temperature is 0.94(5)To, where To is the value for a non-interacting gas in the thermodynamic limit. We determine the energy form a model-independent analysis of the spatial absorption profile, after ballistic expansion, of the atom cloud. We observe a distinct change in slope of the energy-temperature curve near the transition, which indicates a sharp feature in the specific heat.
Physical Review Letters
Bose-Einstein condensation, ground-state fraction, specific heat
, Jin, D.
, Matthews, M.
, Wieman, C.
and Cornell, E.
Bose-Einstine condensation in a dilute gas: Measurement of energy and ground state occupation, Physical Review Letters
(Accessed September 30, 2023)