Coexistence of Replica Bands and Superconductivity in FeSe Monolayer Films

S N Rebec; T Jia; C Zhang; M Hashimoto; D-H Lu; R G Moore; Z-X Shen

doi:10.1103/PhysRevLett.118.067002

Coexistence of Replica Bands and Superconductivity in FeSe Monolayer Films

Phys Rev Lett. 2017 Feb 10;118(6):067002. doi: 10.1103/PhysRevLett.118.067002. Epub 2017 Feb 10.

Authors

S N Rebec^{1

2}, T Jia^{2

3}, C Zhang^{2

3}, M Hashimoto⁴, D-H Lu⁴, R G Moore², Z-X Shen^{1

2

3}

Affiliations

¹ Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
² Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
³ Department of Physics, Stanford University, Stanford, California 94305, USA.
⁴ Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.

PMID: 28234508
DOI: 10.1103/PhysRevLett.118.067002

Abstract

To elucidate the mechanisms behind the enhanced T_{c} in monolayer (1 ML) FeSe on SrTiO_{3} (STO), we grew highly strained 1 ML FeSe on the rectangular (100) face of rutile TiO_{2}, and observed the coexistence of replica bands and superconductivity with a T_{c} of 63 K. From the similar T_{c} between this system and 1ML FeSe on STO (001), we conclude that strain and dielectric constant are likely unimportant to the enhanced T_{c} in these systems. A systematic comparison of 1 ML FeSe on TiO_{2} with other systems in the FeSe family shows that while charge transfer alone can enhance T_{c}, it is only with the addition of interfacial electron-phonon coupling that T_{c} can be increased to the level seen in 1 ML FeSe on STO.