Electron-phonon coupling in the ordered phase of Rb on monolayer graphene

Woo Jong Shin, Sung Won Jung, Yeongsup Sohn, Sae Hee Ryu, Minjae Huh, Keun Su Kim

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2 Citations (Scopus)

Abstract

In the mechanism of two-dimensional (2D) superconductivity in doped graphene, it was predicted that the presence of dopant bands plays a key role. However, it has been challenging to fabricate an ordered phase of alkali metals on graphene owing to its van-der-Waals nature. We systematically study the phase formation of Rb on graphene epitaxially grown on H-passivated SiC(0001). We found a range of control parameters that stabilize the well-ordered 2 × 2 phase (RbC8), as confirmed by in-situ low-energy electron diffraction. Angle-resolved photoemission (ARPES) spectra taken from the 2 × 2 phase show a folded band of graphene and a parabolic band of Rb. In the vicinity of the Fermi level, the self-energy extracted from ARPES data reveals a clear signature of electronic coupling to the in-plane and out-of-plane phonon modes of C and Rb atoms. The electronic coupling of graphene to the in-plane vibration mode of Rb atoms is identified as a key factor for the enhancement of electron-phonon coupling.

Original languageEnglish
Pages (from-to)484-488
Number of pages5
JournalCurrent Applied Physics
Volume20
Issue number4
DOIs
Publication statusPublished - 2020 Apr

Bibliographical note

Funding Information:
This work was supported from the National Research Foundation (NRF) of Korea (Grants No. 2017R1A2B3011368 , No. 2017R1A5A1014862 , and No. 2018K1A3A7A09027641 ), and the Future-leading Research Initiative of 2019–22-0079 of Yonsei University . The ALS was supported by the U. S. Department of Energy, Office of Sciences under Contract No. DE-AC02-05CH11231 . We thank A. Bostwick, R. J. Koch, T. Seyller, and J. Denlinger for help in ARPES experiments.

Funding Information:
This work was supported from the National Research Foundation (NRF) of Korea (Grants No. 2017R1A2B3011368, No. 2017R1A5A1014862, and No. 2018K1A3A7A09027641), and the Future-leading Research Initiative of 2019?22-0079 of Yonsei University. The ALS was supported by the U. S. Department of Energy, Office of Sciences under Contract No. DE-AC02-05CH11231. We thank A. Bostwick, R. J. Koch, T. Seyller, and J. Denlinger for help in ARPES experiments.

Publisher Copyright:
© 2020 Korean Physical Society

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Physics and Astronomy(all)

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