Eddleman Seed Project Published in PRL

Excerpt from APS article:

Stuck in the middle. The matter waves are created by using lasers (four red beams) to trap a Bose-Einstein condensate of ultracold atoms (red and blue sphere) inside an optical lattice (periodic array of ellipsoids). Two sheets of light (green) reflect the atoms between them. One of the light sheets can be moved using an acousto-optic deflector (AOD), creating a periodic variation in the length of the cavity that strongly affects the behavior of the matter waves.

Theoretical work has shown that an optical cavity operating in this regime would provide an effective analogue for studying the behavior of light traveling through curved spacetime. For an optical cavity, however, the need to move a mirror at near-light speeds has so far prevented researchers from creating these conditions. To overcome this problem, David Weld and colleagues at the University of California, Santa Barbara, replaced the solid mirrors with sheets of laser light. In their experimental setup, these light mirrors confine and reflect matter waves of ultracold lithium atoms in a Bose-Einstein condensate. The team created matter waves that propagated at a nearly constant speed, similar to light, but traveling at less than 1 m/s, which made it easier to reach the regime of interest.

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