Coexistence of Weak and Strong Coupling Mechanism, in an Iron-Based Superconductor FeSe 0.5 Te 0.5: Possible Signature of BCS-BEC Crossover

S. Kunwar*, R. M. Hamad, Kh A. Ziq

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

In this work, we present the scanning tunneling microscopy/spectroscopy (STM/STS) studies of an iron-based superconductor, FeSe0.5Te0.5. We obtained differential conductance (dI/dV) spectra and extracted the value of the superconducting order parameter Δ using extended Bardeen Cooper Schieffer (BCS) phenomenology for anisotropic s-wave pairing. We observed widespread values of Δ from ∼0.6 to ∼4.5 meV, with distinct two peaks in the histogram around 1 and 3 meV. The corresponding values of 2Δ/kBTc for the peaks are ∼1.5 and ∼5.0, respectively, indicating coexistence of weak and strong coupling mechanism. We also found two different coupling mechanisms through Δ to Fermi energy ratio (Δ/Ef) of the material; which infers to the possible composite superconductivity in the realm of BCS-Bose Einstein Condensate (BEC) crossover.

Original languageEnglish
Pages (from-to)3183-3188
Number of pages6
JournalJournal of Superconductivity and Novel Magnetism
Volume30
Issue number11
DOIs
StatePublished - 1 Nov 2017

Bibliographical note

Publisher Copyright:
© 2017, Springer Science+Business Media New York.

Keywords

  • BCS-BEC crossover in high- T superconductor
  • Coupling mechanism in iron-based superconductor
  • High- T superconductor
  • Iron-based superconductor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Fingerprint

Dive into the research topics of 'Coexistence of Weak and Strong Coupling Mechanism, in an Iron-Based Superconductor FeSe 0.5 Te 0.5: Possible Signature of BCS-BEC Crossover'. Together they form a unique fingerprint.

Cite this