Superconducting-Gap Anisotropy of Iron Pnictides Investigated via Combinatorial Microwave Measurements.

ABSTRACT: One of the most significant issues for superconductivity is clarifying the momentum-dependent superconducting gap ?([Formula: see text]), which is closely related to the pairing mechanism. To elucidate the gap structure, it is essential to investigate ?([Formula: see text]) in as many different physical quantities as possible and to crosscheck the results obtained in different methods with each other. In this paper, we report a combinatorial investigation of the superfluid density and the flux-flow resistivity of iron-pnictide superconductors; LiFeAs and BaFe₂(As_1-xP_x)₂ (x?=?0.3, 0.45). We evaluated ?([Formula: see text]) by fitting these two-independent quantities with a two-band model simultaneously. The obtained ?([Formula: see text]) are consistent with the results observed in angle-resolved photoemission spectroscopy (ARPES) and scanning-tunneling spectroscopy (STS) studies. We believe our approach is a powerful method for investigating ?([Formula: see text]) because it does not require a sample with clean surface unlike ARPES and STS experiments, or a rotational magnetic-field system for direct measurements of the angular dependence of thermodynamic quantities.

SUBMITTER: Okada T 

PROVIDER: S-EPMC7184760 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature