Efficient rapid production of a Bose-Einstein condensate by overcoming serious three-body loss

Abstract

We report the efficient production of a large Bose-Einstein condensate in $^{87}\mathrm{Rb}$ atoms. This is achieved by quickly reducing the radio frequency of the magnetic field at a rate of $\ensuremath{-}96.8\phantom{\rule{0.3em}{0ex}}\mathrm{kHz}∕\mathrm{s}$ during the final stage of evaporative cooling, and we have produced a condensate with $(2.2\ifmmode\pm\else\textpm\fi{}0.1)\ifmmode\times\else\texttimes\fi{}{10}^{6}$ atoms against a serious three-body recombination loss. We observed the dependence of the cooling efficiency on the rate at which the truncated energy changes by measuring the condensate growth for three kinds of radio-frequency sweep. The experimental results quantitatively agree with calculations based on the quantum kinetic theory of a Bose gas.