1. Spectral function of the K/Si(111):B surface state: the bipolaronic CDW scenario
- Author
-
Yannick Fagot-Revurat, Bertrand Kierren, C. Tournier-Colletta, Luis Cardenas, and Daniel Malterre
- Subjects
Surface (mathematics) ,Physics ,Coupling ,Bipolaron ,Radiation ,Condensed matter physics ,Phonon ,Mott insulator ,Angle-resolved photoemission spectroscopy ,Function (mathematics) ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Condensed Matter::Superconductivity ,Condensed Matter::Strongly Correlated Electrons ,Physical and Theoretical Chemistry ,Ground state ,Spectroscopy - Abstract
Very recently, new LEED, STM and ARPES measurements on the (1/3)ML K/Si(1 1 1):B interface have shed the light on the role of phonons and force to reconsider the nature of the ground state, formerly proposed to be a Mott insulator. In this paper, we present simulations of the one-electron spectral function A ( E ) . These are based on the atomic Holstein–Hubbard model, which is relevant in the strong electron–phonon coupling limit. The exact spectral function has been analysed carefully with special attention on the gap behaviour as a function of the on-site repulsion. We show that the spectral funcion is the same for opposite values of the effective on-site repulsion. The observed reconstruction favours the negative- U e f f case, which corresponds to a bipolaronic charge-ordered ground state. Finally, the ARPES lineshape is reproduced correctly with fitting parameters in agreement with the literature.
- Published
- 2010
- Full Text
- View/download PDF