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Title: Coexistence of Replica Bands and Superconductivity in FeSe Monolayer Films

Abstract

To elucidate the mechanisms behind the enhanced Tc 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 Tc of 63 K. From the similar Tc between this system and 1ML FeSe on STO (001), we conclude that strain and dielectric constant are likely unimportant to the enhanced Tc in these systems. Here, 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 Tc, it is only with the addition of interfacial electron-phonon coupling that Tc can be increased to the level seen in 1 ML FeSe on STO.

Authors:
 [1];  [2];  [2];  [3];  [3];  [3];  [1]
  1. Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States)
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1393495
Alternate Identifier(s):
OSTI ID: 1343472
Grant/Contract Number:
AC02-76SF00515
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 118; Journal Issue: 6; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Rebec, S. N., Jia, T., Zhang, C., Hashimoto, M., Lu, D. -H., Moore, R. G., and Shen, Z. -X.. Coexistence of Replica Bands and Superconductivity in FeSe Monolayer Films. United States: N. p., 2017. Web. doi:10.1103/PhysRevLett.118.067002.
Rebec, S. N., Jia, T., Zhang, C., Hashimoto, M., Lu, D. -H., Moore, R. G., & Shen, Z. -X.. Coexistence of Replica Bands and Superconductivity in FeSe Monolayer Films. United States. doi:10.1103/PhysRevLett.118.067002.
Rebec, S. N., Jia, T., Zhang, C., Hashimoto, M., Lu, D. -H., Moore, R. G., and Shen, Z. -X.. Fri . "Coexistence of Replica Bands and Superconductivity in FeSe Monolayer Films". United States. doi:10.1103/PhysRevLett.118.067002. https://www.osti.gov/servlets/purl/1393495.
@article{osti_1393495,
title = {Coexistence of Replica Bands and Superconductivity in FeSe Monolayer Films},
author = {Rebec, S. N. and Jia, T. and Zhang, C. and Hashimoto, M. and Lu, D. -H. and Moore, R. G. and Shen, Z. -X.},
abstractNote = {To elucidate the mechanisms behind the enhanced Tc in monolayer (1 ML) FeSe on SrTiO3 (STO), we grew highly strained 1 ML FeSe on the rectangular (100) face of rutile TiO2, and observed the coexistence of replica bands and superconductivity with a Tc of 63 K. From the similar Tc between this system and 1ML FeSe on STO (001), we conclude that strain and dielectric constant are likely unimportant to the enhanced Tc in these systems. Here, a systematic comparison of 1 ML FeSe on TiO2 with other systems in the FeSe family shows that while charge transfer alone can enhance Tc, it is only with the addition of interfacial electron-phonon coupling that Tc can be increased to the level seen in 1 ML FeSe on STO.},
doi = {10.1103/PhysRevLett.118.067002},
journal = {Physical Review Letters},
number = 6,
volume = 118,
place = {United States},
year = {Fri Feb 10 00:00:00 EST 2017},
month = {Fri Feb 10 00:00:00 EST 2017}
}

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Cited by: 19works
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  • We report on molecular beam epitaxy growth of stoichiometric and superconducting FeSe crystalline thin films on double-layer graphene. Layer-by-layer growth of high-quality films has been achieved in a well-controlled manner by using Se-rich condition, which allow us to investigate the thickness-dependent superconductivity of FeSe. In situ low-temperature scanning tunneling spectra reveal that the local superconducting gap in the quasiparticle density of states is visible down to two triple layers for the minimum measurement temperature of 2.2 K, and that the transition temperature T{sub c} scales inversely with film thickness.
  • In this paper, we study the consequences of an electron–phonon (e–ph) interaction that is strongly peaked in the forward scattering (more » $${\bf{q}}=0$$) direction in a two-dimensional superconductor using Migdal–Eliashberg theory. We find that strong forward scattering results in an enhanced T c that is linearly proportional to the strength of the dimensionless e–ph coupling constant $${\lambda }_{m}$$ in the weak coupling limit. This interaction also produces distinct replica bands in the single-particle spectral function, similar to those observed in recent angle-resolved photoemission experiments on FeSe monolayers on SrTiO 3 and BaTiO 3 substrates. Finally, by comparing our model to photoemission experiments, we infer an e–ph coupling strength that can provide a significant portion of the observed high T c in these systems.« less
  • In this paper, we study the consequences of an electron–phonon (e–ph) interaction that is strongly peaked in the forward scattering (more » $${\bf{q}}=0$$) direction in a two-dimensional superconductor using Migdal–Eliashberg theory. We find that strong forward scattering results in an enhanced T c that is linearly proportional to the strength of the dimensionless e–ph coupling constant $${\lambda }_{m}$$ in the weak coupling limit. This interaction also produces distinct replica bands in the single-particle spectral function, similar to those observed in recent angle-resolved photoemission experiments on FeSe monolayers on SrTiO 3 and BaTiO 3 substrates. Finally, by comparing our model to photoemission experiments, we infer an e–ph coupling strength that can provide a significant portion of the observed high T c in these systems.« less