Giant kink in electron dispersion of strongly coupled lead nanowires

Our photoelectron spectroscopy study shows a giant kink in the electron dispersion, a sign of high-energy manybody interactions of electrons, in a well-ordered Pb nanowire array self-assembled on a silicon substrate. We show that the unique electronic band structure due to the strong lateral coupling and the atomic structure of the nanowires drives an enhanced manybody interaction for kinked electron dispersion. The major giant kink mechanisms discussed previously, the magnetic and plasmonic excitations, are not relevant in the present system, supporting the recent kink theory based purely on electron-electron correlation. This suggests that tailored electronic band structures in nano array systems can provide unprecedented ways to study manybody interactions of electrons.