Ubiquitous strong electron phonon coupling at the interface of FeSe/SrTiO3

Abstract

The high temperature superconductivity in single-unit-cell (1UC) FeSe on SrTiO3 (STO)(001) and the observation of replica bands by angle-resolved photoemission spectroscopy (ARPES) have led to the conjecture that the coupling between FeSe electron and the STO phonon is responsible for the enhancement of Tc over other FeSe-based superconductors1,2. However the recent observation of a similar superconducting gap in FeSe grown on the (110) surface of STO raises the question of whether a similar mechanism applies3,4. Here we report the ARPES study of the electronic structure of FeSe grown on STO(110). Similar to the results in FeSe/STO(001), clear replica bands are observed. We also present a comparative study of STO (001) and STO(110) bare surfaces, where photo doping generates metallic surface states. Similar replica bands separating from the main band by approximately the same energy are observed, indicating this coupling is a generic feature of the STO surfaces and interfaces. Our findings suggest that the large superconducting gaps observed in FeSe films grown on two different STO surface terminations are likely enhanced by a common coupling between FeSe electrons and STO phonons.

12 pages, 4 figures

References in corpus (4)

• Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
• Structure determination and coexistence of superconductivity and antiferromagnetic order in (Li0.8Fe0.2)OHFeSe
• Control of a two-dimensional electron gas on SrTiO3(111) by atomic oxygen
• Phase diagram of (Li1-xFex)OHFeSe: a bridge between iron selenide and arsenide superconductors

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• Interfacial Electron-Phonon Coupling Constants Extracted from Intrinsic Replica Bands in Monolayer FeSe/SrTiO${}_3$
• Direct probing of a large spin-orbit coupling in the FeSe superconducting monolayer on STO: Evidence for nontrivial topological states
• Non-universal current flow near the metal-insulator transition in an oxide interface
• Screening Induced Crossover between Phonon- and Plasmon-Mediated Pairing in Layered Superconductors
• Magic Doping and Robust Superconductivity in Monolayer FeSe on Titanates
• Preliminary Tc calculations for iron-based superconductivity in NaFeAs, LiFeAs, FeSe and nanostructured FeSe/SrTiO3 Superconductors
• Non-perturbative Green's function method to determine the electronic spectral function due to electron-phonon interactions: Application to a graphene model from weak to strong coupling
• Direct Visualization and Manipulation of Tunable Quantum Well State in Semiconducting Nb2SiTe4
• Flat bands and temperature-driven phase transition in quasi-one-dimensional zigzag chains
• Evidence of electron interaction with an unidentified bosonic mode in superconductor CsCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Interface suppressed nematicity and enhanced superconductivity of FeSe/NdFeO3 in the low doping regime
• Phonon Induced Instabilities in Correlated Electron Hamiltonians
• Modulation doping of the FeSe monolayer on SrTiO${}_3$
• Direct evidence of a charge depletion region at the interface of Van der Waals monolayers and dielectric oxides: The case of superconducting FeSe/STO
• The interactions between antiferromagnetism, tetrahedral sites and electron-phonon coupling in FeSe1-xTex and FeSe/SrTiO3
• The influence of antiferromagnetism, soft out-of plane phonons and heavy electrons on the superconducting pairing mechanism of Ba1-xKxFe2As2
• Superconductor-Insulator transition in a two-orbital attractive Hubbard model with Hund's exchange
• Temperature evolution of the Fermi surface of the FeSe monolayer on SrTiO${}_3$