We investigate the time evolution of freely expanded Bose-Einstein condensates by measuring their aspect ratios at different times after their release from a magnetic trap. In these measurements the condensates contain no more than 9000 87Rb atoms. By varying the trapping frequency and atom number, we measure the condensate aspect ratios at different expansion times in free space. We compare our measurements with those calculated from the Thomas-Fermi model and a direct numerical solution. Under our trapping condition, the data of the time dependent aspect ratios of the freely expanded condensates reasonably agrees with the numerical calculations, but shows a clear deviation from the predictions of the Thomas-Fermi model when the atom number in the condensates is small.
|Number of pages||11|
|Journal||Chinese Journal of Physics|
|Issue number||2 I|
|State||Published - 1 Apr 2007|