Electron-phonon coupling in the ordered phase of Rb on monolayer graphene
| Autor: | Keun Su Kim, Minjae Huh, Sungwon Jung, Sae Hee Ryu, Yeongsup Sohn, Woo Jong Shin |
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| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Superconductivity Materials science Condensed matter physics Dopant Graphene Phonon Fermi level General Physics and Astronomy Angle-resolved photoemission spectroscopy 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences law.invention symbols.namesake Electron diffraction law Condensed Matter::Superconductivity Phase (matter) 0103 physical sciences Physics::Atomic and Molecular Clusters symbols General Materials Science 0210 nano-technology |
| Zdroj: | Current Applied Physics. 20:484-488 |
| ISSN: | 1567-1739 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
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