Phillips and his colleagues produced a focused directional output from the Bose-Einstein condensate by firing two laser beams into the condensate. One beam adds energy to the atoms, while the second stimulates them to emit photons and drop down to a lower energy state. As the photons of the second laser beam have slightly less energy than photons from the first beam, the atoms gain a small amount of energy. This energy is converted into momentum, which pushes the atoms into a given in a direction.

To create the four-wave mixing, Phillips and his team again started with a Bose-Einstein condensate. This time, however, they pumped a series of Bragg laser pulses into the atom cloud. Each pulse pushed some of the atoms out of the condensate. The pulses created three wave packets, which immediately started to overlap and produced a new wave packet with its own unique momentum.