Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: Multiband superconductivity and electron-boson coupling

D. Daghero, P. Pecchio, G. A. Ummarino, F. Nabeshima, Y. Imai, A. Maeda, I. Tsukada, S. Komiya, R. S. Gonnelli

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)

Abstract

We report on a study of the superconducting order parameter in Fe(Te1?xSex) thin films (with different Se contents: x = 0.3, 0.4, 0.5) by means of point-contact Andreev-reflection spectroscopy (PCARS). The PCARS spectra show reproducible evidence of multiple structures, namely two clear conductance maxima associated to a superconducting gap of amplitude δE ≃ 2.75kBTc and additional shoulders at higher energy that, as we show, are the signature of the strong interaction of charge carriers with a bosonic mode whose characteristic energy coincides with the spin-resonance energy. The details of some PCARS spectra at low energy suggest the presence of a smaller and not easily discernible gap of amplitude δH simel 1.75kBTc. The existence of this gap and its amplitude are confirmed by PCARS measurements in ? Fe(Te1-xSex) single crystals. The values of the two gaps δE and δH, once plotted as a function of the local critical temperature TcA , turn out to be in perfect agreement with the results obtained by various experimental techniques reported in literature.

Original languageEnglish
Article number124014
JournalSuperconductor Science and Technology
Volume27
Issue number12
DOIs
Publication statusPublished - 2014 Dec 1
Externally publishedYes

Keywords

  • Andreev reflection spectroscopy
  • chalcogenide superconductors
  • superconducting films

ASJC Scopus subject areas

  • Ceramics and Composites
  • Condensed Matter Physics
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: Multiband superconductivity and electron-boson coupling'. Together they form a unique fingerprint.

Cite this