Since the creation of a Bose–Einstein condensate (BEC) nearly 20 years ago, the toolbox for manipulating ultracold gases has greatly expanded. Researchers have simulated the transition from a bosonic superfluid to a Mott insulator, led fermions continuously from a molecular BEC to a Bardeen-Cooper-Schrieffer superfluid composed of widely spaced Cooper pairs, and reproduced many other phenomena seen in condensed-matter systems. And they want to do more.
Researchers envision using ultracold gases to simulate a real solid. For example, interfering laser beams can create a periodically varying potential energy in which the atoms sit, reminiscent of electrons in a crystal lattice; experimenters can adjust the depth of the potential wells or the interaction strength between the atoms. The advantage of using an ultracold atomic system is that it is much cleaner than a real solid and allows experimenters to exert much greater control over the relevant parameters.
To expand the types...
