Abstract

The isovalent-substituted iron pnictide compound SrFe2(As1−xPx)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 kz-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.

Details

Title
Band-dependent superconducting gap in SrFe2(As0.65P0.35)2 studied by angle-resolved photoemission spectroscopy
Author
Suzuki, H 1   VIAFID ORCID Logo  ; Kobayashi, T 2 ; Miyasaka, S 3 ; Okazaki, K 4   VIAFID ORCID Logo  ; Yoshida, T 5 ; Horio, M 1   VIAFID ORCID Logo  ; L C C Ambolode II 1 ; Ota, Y 6 ; Yamamoto, H 6 ; Shin, S 7   VIAFID ORCID Logo  ; Hashimoto, M 8 ; Lu, D H 8   VIAFID ORCID Logo  ; Shen, Z-X 8   VIAFID ORCID Logo  ; Tajima, S 3 ; Fujimori, A 5 

1  Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, Japan 
2  Department of Physics, Osaka University, Toyonaka, Osaka, Japan 
3  Department of Physics, Osaka University, Toyonaka, Osaka, Japan; JST, Transformative Research-Project on Iron Pnictides (TRIP), Chiyoda, Tokyo, Japan 
4  Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, Japan; Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwa, Chiba, Japan 
5  Department of Physics, University of Tokyo, Bunkyo-ku, Tokyo, Japan; JST, Transformative Research-Project on Iron Pnictides (TRIP), Chiyoda, Tokyo, Japan 
6  Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwa, Chiba, Japan 
7  JST, Transformative Research-Project on Iron Pnictides (TRIP), Chiyoda, Tokyo, Japan; Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwa, Chiba, Japan 
8  Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California, USA 
Pages
1-9
Publication year
2019
Publication date
Nov 2019
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41598-019-52887-y
ProQuest document ID
2313769051
Copyright
© 2019. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.