Vibrationally resolved core-photoelectron spectroscopy as an infinite-slitinterferometry - art. no. 012504

During a molecular vibration, an atom changes continuously its position. Ju st as the emitted photoelectron waves, the electromagnetic waves absorbed b y the atom in the different positions are strictly coherent and have differ ent well-defined phases. These phases depend on the relation between the in stantaneous internuclear distance and the photoelectron, respectively, phot on wavelengths. We predict that the interference of these coherent waves st rongly influences the vibrational profile of the photoelectron spectra of c ore electrons in a molecule. This effect increases with increasing x-ray ph oton frequency and results in a deformation and broadening of the vibration al profile. In the case of surface adsorbed molecules, the vibrational prof ile depends strongly on the direction of the photoelectron ejection and pho ton momentum, and the orientational sensitivity of a vibrational profile ca n even be used as a tool to define the orientation of adsorbed molecules.