Young's double-slit experiment using two-center core-level photoemission: Photoelectron scattering effects

Core-level photoemission from N-2 can be considered as an analogue of Young's double-slit experiment (YDSE) in which the double-slit is replaced by a pair of N 1s orbitals. N 1s photoelectron spectra of N-2 are measured in the extended photon energy region up to similar to 1 keV at unprecedented resolution. The measured ratio between the 1 sigma(g) and 1 sigma(u) photoionization cross-sections oscillates as a function of electron momentum due to interference effects analogue to YDSE. We found a shift of the interference pattern with respect to a prediction by a simple model for coherent two-center emission, the Cohen-Fano formula, and attributed it to photoelectron scattering by the neighboring atom. We demonstrate that the shift can be used to determine the scattering phase of the photoelectron. (C) 2006 Elsevier B.V. All rights reserved.