Intrinsic Charge Dynamics in High-Tc AFeAs(O,F) Superconductors

A. Charnukha, D. Pröpper, N. D. Zhigadlo, M. Naito, M. Schmidt, Zhe Wang, J. Deisenhofer, A. Loidl, B. Keimer, A. V. Boris, and D. N. Basov
Phys. Rev. Lett. 120, 087001 – Published 23 February 2018
PDFHTMLExport Citation

Abstract

We report the first determination of the in-plane complex optical conductivity of 1111 high-Tc superconducting iron oxypnictide single crystals PrFeAs(O,F) and thin films SmFeAs(O,F) by means of conventional and microfocused infrared spectroscopy, ellipsometry, and time-domain THz transmission spectroscopy. A strong itinerant contribution is found to exhibit a dramatic difference in coherence between the crystal and the film. Using extensive temperature-dependent measurements of THz transmission, we identify a previously undetected 2.5-meV collective mode in the optical conductivity of SmFeAs(O,F), which is strongly suppressed at Tc and experiences an anomalous T-linear softening and narrowing below T*110KTc. The suppression of the infrared absorption in the superconducting state reveals a large optical superconducting gap with a similar gap ratio 2Δ/kBTc7 in both materials, indicating strong pairing.

  • Figure
  • Figure
  • Figure
  • Figure
  • Received 4 July 2017

DOI:https://doi.org/10.1103/PhysRevLett.120.087001

© 2018 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

A. Charnukha1,2,3,*, D. Pröpper3, N. D. Zhigadlo4,5, M. Naito6, M. Schmidt7, Zhe Wang7,†, J. Deisenhofer7, A. Loidl7, B. Keimer3, A. V. Boris3, and D. N. Basov1,8

  • 1Physics Department, University of California-San Diego, La Jolla, California 92093, USA
  • 2Leibniz Institute for Solid State and Materials Research, IFW, 01069 Dresden, Germany
  • 3Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
  • 4Laboratory for Solid State Physics, ETH Zurich, CH-8093 Zurich, Switzerland
  • 5Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
  • 6Department of Applied Physics, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
  • 7Experimental Physics V, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, D-86159 Augsburg, Germany
  • 8Department of Physics, Columbia University, New York, New York 10027, USA

  • *acharnukha@ucsd.edu.
  • Present address: Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany.

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 120, Iss. 8 — 23 February 2018

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×