Interfacial phonons between iron-based superconductors (FeSCs) and perovskite substrates have received considerable attention due to the possibility of enhancing preexisting superconductivity. Using scanning tunneling spectroscopy, we studied the correlation between superconductivity and e-ph interaction with interfacial-phonons in an iron-based superconductor Sr2VO3FeAs (Tc≈ 33 K) made of alternating FeSC and oxide layers. The quasiparticle interference measurement over regions with systematically different average superconducting gaps due to the e-ph coupling locally modulated by O vacancies in VO2 layer, and supporting self-consistent momentum-dependent Eliashberg calculations provide a unique real-space evidence of the forward-scattering interfacial phonon contribution to the total superconducting pairing.
@article{arxiv.1608.00886,
title = {Correlation of Fe-based Superconductivity and Electron-Phonon Coupling in an FeAs/Oxide Heterostructure},
author = {Seokhwan Choi and Steven Johnston and Won-Jun Jang and Klaus Koepernik and Ken Nakatsukasa and Jong Mok Ok and Hyun-Jung Lee and Hyun Woo Choi and Alex Taekyung Lee and Alireza Akbari and Yannis K. Semertzidis and Yunkyu Bang and Jun Sung Kim and Jhinhwan Lee},
journal= {arXiv preprint arXiv:1608.00886},
year = {2017}
}