Environmental control of electron-phonon coupling in barium doped graphene

Author(s)
N. I. Verbitskiy, A. V. Fedorov, C. Tresca, G. Profeta, L. Petaccia, B. V. Senkovskiy, D. Yu Usachov, D. V. Vyalikh, L. V. Yashina, A. A. Eliseev, T. Pichler, A. Grüneis
Abstract

Two-dimensional superconductivity in alkali-and alkaline-Earth-metal doped monolayer graphene has been explained in the framework of electron-phonon coupling (EPC) and experiments yielded superconducting transition temperatures (TC) up to 6 K. In contrast to bulk graphite intercalation compounds, the interface of doped graphene with its environment affects its physical properties. Here we present a novel and well-defined BaC8 interface structure in Ba-doped single-layer graphene on Au and Ge substrates. We use angle-resolved photoemission spectroscopy in combination with ab initio modelling to extract the Eliashberg function and EPC for both substrates. This allows us to quantitatively assess the environmental effects for both Au and Ge substrates on superconductivity in graphene. We show that for semiconducting Ge substrates, the doping level and EPC are higher. Our study highlights that both dopant order and the metallicity of the substrate can be used to control EPC and hence superconductivity.

Organisation(s)
Electronic Properties of Materials
Journal
2D Materials
Volume
3
No. of pages
7
ISSN
2053-1583
DOI
https://doi.org/10.1088/2053-1583/3/4/045003
Publication date
12-2016
Publication status
Published
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics
Keywords
graphene, chemical doping, angle-resolved photoemission, electron-phonon coupling, superconductivity, INTERCALATED BILAYER GRAPHENE, TOTAL-ENERGY CALCULATIONS, WAVE BASIS-SET, SUPERCONDUCTIVITY, GRAPHITE, C6CA, BAC6
Portal url
https://ucris.univie.ac.at/portal/en/publications/environmental-control-of-electronphonon-coupling-in-barium-doped-graphene(e8338896-50f6-4108-8d92-6533f82fd22e).html