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

We report the efficient production of a large Bose-Einstein condensate in $^{87}$Rb atoms. This is achieved by quickly reducing the radio-frequency of the magnetic field at a rate of -96.8 kHz/s during the final stage of evaporative cooling, and we have produced a condensate with ${(2.2 \pm 0.1) \times 10^{6}}$ 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.