Phonon-enhanced superconductivity at the FeSe/SrTiO<sub>3</sub> interface
ORAL
Abstract
Single-layer FeSe on a SrTiO3 substrate, with its extraordinarily large Tc amongst all interfacial superconductors and iron based superconductors, is particularly interesting, but the mechanism underlying its high Tc has remained mysterious. Here we show through isotope effects that electrons in FeSe couple with the oxygen phonons in the substrate, and the superconductivity is enhanced linearly with the coupling strength atop the intrinsic superconductivity of optimally-electron-doped FeSe. Our observations solve the enigma of FeSe/SrTiO3, and experimentally establish the critical role and unique behavior of electron-phonon forward scattering in a correlated high-Tc superconductor. The effective cooperation between interlayer electron-phonon interactions and correlations suggests a path forward in developing more high-Tc interfacial superconductors, and may shed light on understanding the high Tc of bulk high temperature superconductors with layered structures.
*State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
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Presenters
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Qi Song
- Fudan University
- Physics, Massachusetts Inst of Tech-MIT