Modelling of interferometric multiphoton photoemission

A new interferometric multi-photon photoemission scheme has been recently introduced by Güdde et al. 1] and applied to a study of the n=1 image state on Cu(100). We report on the results of a theoretical modelling of this photoemission scheme based on a wave function representation. It incorporates both resonant transitions and two-photon non-resonant transitions. In the case of the n=1 image state on Cu(100), the initial state of the photoemission belongs to a continuum. Summation of the contributions to the photoemission yield from the various initial states is shown to drastically blur the interference structure, acting as an efficient dephasing process. The sensitivity of the new scheme and of the one-colour TR-2PPE scheme to the system dynamical properties is discussed. PACS 73.20.-r; 78.47.+p; 79.60.-i; 82.53.Kp; 42.50.Md