A crystal structure is a natural trap for atoms. Would it not be marvelous if we could create such a trap artificially whenever we like? An optical lattice does just that: In near vacuum, the electrical field of two interfering laser beams can be carefully engineered to hold individual neutral atoms in place. With two lasers for each of the three spatial dimensions, the particles are trapped in the wells of an egg carton-shaped potential. The size of these wells can be adjusted by controlling the frequency and intensity of the laser beams. When the wells are shallow, particles can tunnel and move between neighboring wells. This unique property can be harnessed to create a superfluid state from cold atoms within the optical lattice, opening up new possibilities for studying quantum phenomena and conducting precise experiments in the realm of atomic physics.

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