title: Evolution of fermion pairing from three to two dimensions.
abstract: We follow the evolution of fermion pairing in the dimensional crossover from three-dimensional to two-dimensional as a strongly interacting Fermi gas of ^{6}Li atoms becomes confined to a stack of two-dimensional layers formed by a one-dimensional optical lattice. Decreasing the dimensionality leads to the opening of a gap in radio-frequency spectra, even on the Bardeen-Cooper-Schrieffer side of a Feshbach resonance. The measured binding energy of fermion pairs closely follows the theoretical two-body binding energy and, in the two-dimensional limit, the zero-temperature mean-field Bose-Einstein-condensation to Bardeen-Cooper-Schrieffer crossover theory.
authors.affiliation: Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, MIT, Cambridge, Massachusetts 02139, USA.
authors.forename: Ariel T
authors.initials: AT
authors.lastname: Sommer
authors.forename: Lawrence W
authors.initials: LW
authors.lastname: Cheuk
authors.forename: Mark J H
authors.initials: MJ
authors.lastname: Ku
authors.forename: Waseem S
authors.initials: WS
authors.lastname: Bakr
authors.forename: Martin W
authors.initials: MW
authors.lastname: Zwierlein