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

Core-level photoemission from N2 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 N2 are measured in the extended photon energy region up to ∼ 1 keV at unprecedented resolution. The measured ratio between the 1σg and 1σu 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.