title: Experimental observation of spatial antibunching of photons.
abstract: We report an interference experiment that shows transverse spatial antibunching of photons. Using collinear parametric down-conversion in a Young-type fourth-order interference setup, we show interference patterns that violate classical Schwarz inequality and should not exist at all in a classical description.
authors.affiliation: Departamento de Física, Universidade Federal de Minas Gerais, Caixa Postal 702, Belo Horizonte, MG 30123-970, Brazil.
authors.forename: W A
authors.initials: WA
authors.lastname: Nogueira
authors.forename: S P
authors.initials: SP
authors.lastname: Walborn
authors.forename: S
authors.initials: S
authors.lastname: Pádua
authors.forename: C H
authors.initials: CH
authors.lastname: Monken