Image

The ultra-cold Fermi gas has the property of bursting outward in a preferred direction when released. The figure shows absorption images of the expanding, strongly-interacting gas as a function of time t for t=0.1 ms to t=2.0 ms. Very little motion occurs in the axial direction. Most of the energy is released in the transverse dimensions causing the gas to assume an elliptical shape. In the absence of interactions, the gas would expand with the same speed in all directions.

Back to article