Enhanced electron-phonon coupling at the Au/Mo(112) surface

A detailed investigation of the electronic structure and electron-phonon coupling for a Au monolayer on the Mo(112) surface is presented. The electronic states of bulk Mo and the (112) surface-derived states are seen to strongly hybridize with those of the Au overlayer, resulting in the formation of surface resonance states localized near the surface and the interface of Au/Mo(112). The experimentally extracted self-energy due to the electron-phonon coupling on one of the surface resonance bands gives a good quantitative agreement with the calculations. The strength of electron-phonon coupling for Au/Mo(112) is discussed in terms of the mass enhancement factor and is considerably larger than for the Mo(112) surface. Such an increase in the mass enhancement factor in the vicinity of the Fermi level likely derives from the soft surface phonon modes created upon Au adsorption.