title: Spatial coherence of a polariton condensate.
abstract: We perform Young's double-slit experiment to study the spatial coherence properties of a two-dimensional dynamic condensate of semiconductor microcavity polaritons. The coherence length of the system is measured as a function of the pump rate, which confirms a spontaneous buildup of macroscopic coherence in the condensed phase. An independent measurement reveals that the position and momentum uncertainty product of the condensate is close to the Heisenberg limit. An experimental realization of such a minimum uncertainty wave packet of the polariton condensate opens a door to coherent matter-wave phenomena such as Josephson oscillation, superfluidity, and solitons in solid state condensate systems.
authors.affiliation: Edward L. Ginzton Laboratory, Stanford University, Stanford, California 94305, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Deng
authors.forename: Glenn S
authors.initials: GS
authors.lastname: Solomon
authors.forename: Rudolf
authors.initials: R
authors.lastname: Hey
authors.forename: Klaus H
authors.initials: KH
authors.lastname: Ploog
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Yamamoto