Surface phonon excitation on clean metal surfaces in scanning tunneling microscopy

Emi Minamitani, Ryuichi Arafune, Noriyuki Tsukahara, Yoshitaka Ohda, Satoshi Watanabe, Maki Kawai, Hiromu Ueba, Noriaki Takagi

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

We carry out inelastic electron tunneling spectroscopy (IETS) measurement on a clean Cu(110) surface at 2 K using a scanning tunneling microscope (STM). The spectrum exhibits a single peak at 6 meV, while the phonon density of states (DOS) cannot explain the appearance of this peak. In order to elucidate the origin of the observed peak, we derive a general expression of STM-IETS spectrum for the phonon excitation at a clean metal surface by employing the Keldysh-Green's functional theory. We reveal that the STM-IETS spectrum is proportional to the momentum-resolved Eliashberg function, and not solely to the phonon DOS. By ab initio calculations of the momentum-resolved Eliashberg function combined with the phonon dispersion, we assign the observed peak to the out-of-plane polarized surface phonon mode.

Original languageEnglish
Article number085411
JournalPhysical Review B
Volume93
Issue number8
DOIs
Publication statusPublished - 2016 Feb 8

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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    Minamitani, E., Arafune, R., Tsukahara, N., Ohda, Y., Watanabe, S., Kawai, M., Ueba, H., & Takagi, N. (2016). Surface phonon excitation on clean metal surfaces in scanning tunneling microscopy. Physical Review B, 93(8), [085411]. https://doi.org/10.1103/PhysRevB.93.085411