Many-body interactions and Rashba splitting of the surface state on Cu(110)

Abstract

Using high-resolution angle-resolved photoemission spectroscopy, we elucidate the Rashba splitting of k F = 0.003Å −1 near the Fermi level (E F ) in the Shockley surface state of Cu (110) at the Y point of the surface Brillouin zone. The observed energy-band dispersion exhibits a kink structure at ∼−20 meV, which is a clear indication of band renormalization caused by an electron-phonon interaction. The electron-phonon coupling parameter is found to be λ ep = 0.17 ± 0.02 based on the experimentally obtained real part of the self-energy. First-principle calculations yield λ ep = 0.160 and k F = 0.004Å −1 at E F , which are fully consistent with the experimental results. In addition, the contributions of the electron-electron and electron-phonon interactions to the linewidth of the surface state at the Y point are experimentally determined to be ee ∼ 9 meV and ep ∼ 7 meV, respectively. We demonstrate that the Rashba splitting must be resolved by photoemission line-shape analysis for an accurate determination of the electron self-energy and coupling parameters.

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Electron-phonon coupling in topological surface states: The role of polar optical modes

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Scanning Tunneling Spectroscopy of Subsurface Ag and Ge Impurities in Copper

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