Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

7-7-2017

Journal or Book Title

Science

Volume

357

Issue

6346

First Page

75

Last Page

80

DOI

10.1126/science.aal1575

Abstract

The superconductor iron selenide (FeSe) is of intense interest owing to its unusual nonmagnetic nematic state and potential for high-temperature superconductivity. But its Cooper pairing mechanism has not been determined. We used Bogoliubov quasiparticle interference imaging to determine the Fermi surface geometry of the electronic bands surrounding the Γ = (0, 0) and X = (π/aFe, 0) points of FeSe and to measure the corresponding superconducting energy gaps. We show that both gaps are extremely anisotropic but nodeless and that they exhibit gap maxima oriented orthogonally in momentum space. Moreover, by implementing a novel technique, we demonstrate that these gaps have opposite sign with respect to each other. This complex gap configuration reveals the existence of orbital-selective Cooper pairing that, in FeSe, is based preferentially on electrons from the dyz orbitals of the iron atoms.

Comments

This is the author’s version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published as Sprau, Peter O., Andrey Kostin, Andreas Kreisel, Anna E. Böhmer, Valentin Taufour, Paul C. Canfield, Shantanu Mukherjee, Peter J. Hirschfeld, Brian M. Andersen, and J.C. Séamus Davis. "Discovery of orbital-selective Cooper pairing in FeSe." Science 357, no. 6346 (2017): 75-80. DOI: 10.1126/science.aal1575.

Copyright Owner

The Authors

Language

en

File Format

application/pdf

Published Version

Included in

Physics Commons

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