Delocalization of a Vacancy across Two Neon Atoms Bound by the van der Waals Force

We experimentally study 2p photoionization of neon dimers (Ne₂) at a photon energy of hν=36.56 eV. By postselection of ionization events which lead to a dissociation into Ne⁺+Ne we obtain the photoelectron angular emission distribution in the molecular frame. This distribution is symmetric with respect to the direction of the charged vs neutral fragment. It shows an inverted Cohen-Fano double slit interference pattern of two spherical waves emitted coherently but with opposite phases from the two atoms of the dimer.