BEC interferometer (Ring 1)


If an atomic vapour of bosons is cold and dense enough that the inter-atomic spacing approaches the thermal de Broglie wavelength, then a phase transition occurs and all of the atoms coalesce into the same (lowest energy) quantum state. Such a Bose-Einstein condensate (BEC), in which all of the atoms behave in essentially the same way, is thus the atomic analogue of a laser – an atom laser. These atom lasers are extremely cold (~10nK) coherent macroscopic quantum objects large enough to be observed on a simple CCD camera – bringing textbook quantum mechanics to life. Achievements in the field to date ensured the 2001 Nobel Physics Prize for those who first experimentally realised BEC. BEC phase transitionInterference fringes: black=atoms, white=no atoms
In 2003 we created the first Bose-Einstein condensate (BEC) in Scotland at Strathclyde, joining other groups worldwide. Our condensate contains about 5 105 87Rb atoms in the |F=2,mF=2> state. The BEC was created at a localised position at the top of our storage ring, and in 2005 was one of the first experiments in the world to observe BEC propagation in a ring. We can also split the condensate into two halves which rotate in opposite directions around the ring. Recently we revisited a classic MIT experiment and made the equivalent of a matter wave Young’s slits interferometer.

Images from the BEC experiment


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