Band-dependent superconducting gap in SrFe2(As0.65P0.35)2 studied by angle-resolved photoemission spectroscopy

Scientific Reports. 2019;9(1):1-9 DOI 10.1038/s41598-019-52887-y

 

Journal Homepage

Journal Title: Scientific Reports

ISSN: 2045-2322 (Online)

Publisher: Nature Publishing Group

LCC Subject Category: Medicine | Science

Country of publisher: United Kingdom

Language of fulltext: English

Full-text formats available: PDF, HTML

 

AUTHORS

H. Suzuki (Department of Physics, University of Tokyo)
T. Kobayashi (Department of Physics, Osaka University)
S. Miyasaka (Department of Physics, Osaka University)
K. Okazaki (Department of Physics, University of Tokyo)
T. Yoshida (Department of Physics, University of Tokyo)
M. Horio (Department of Physics, University of Tokyo)
L. C. C. Ambolode (Department of Physics, University of Tokyo)
Y. Ota (Institute for Solid State Physics (ISSP), University of Tokyo)
H. Yamamoto (Institute for Solid State Physics (ISSP), University of Tokyo)
S. Shin (JST, Transformative Research-Project on Iron Pnictides (TRIP), Chiyoda)
M. Hashimoto (Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory)
D. H. Lu (Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory)
Z.-X. Shen (Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory)
S. Tajima (Department of Physics, Osaka University)
A. Fujimori (Department of Physics, University of Tokyo)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 20 weeks

 

Abstract | Full Text

Abstract The isovalent-substituted iron pnictide compound SrFe2(As1−x P x )2 exhibits multiple evidence for nodal superconductivity via various experimental probes, such as the penetration depth, nuclear magnetic resonance and specific heat measurements. The direct identification of the nodal superconducting (SC) gap structure is challenging, partly because the presence of nodes is not protected by symmetry but instead caused by an accidental sign change of the order parameter, and also because of the three-dimensionality of the electronic structure. We have studied the SC gaps of SrFe2(As0.65P0.35)2 in three-dimensional momentum space by synchrotron and laser-based angle-resolved photoemission spectroscopy. The three hole Fermi surfaces (FSs) at the zone center have SC gaps with different magnitudes, whereas the SC gaps of the electron FSs at the zone corner are almost isotropic and k z -independent. As a possible nodal SC gap structure, we propose that the SC gap of the outer hole FS changes sign around the Z-X [(0, 0, 2π) − (π, π, 2π)] direction.