Publication Date

4-1-2018

Department

Ames Laboratory; Physics and Astronomy

Campus Units

Physics and Astronomy, Ames Laboratory

Report Number

IS-J 9639

DOI

10.1103/PhysRevB.97.140503

Journal Title

Physical Review B

Volume Number

97

Issue Number

14

First Page

140503(R)

Abstract

The temperature dependence of the in-plane magnetic penetration depth (lambda(ab)) in an extensively characterized sample of superconducting CaKFe4As4 (T-c similar or equal to 35 K) was investigated using muon-spin rotation (mu SR). A comparison of lambda(-2)(ab) (T) measured by mu SR with the one inferred from angle-resolved photoemission spectroscopy (ARPES) data confirms the presence of multiple gaps at the Fermi level. An agreement between mu SR and ARPES requires the presence of additional bands, which are not resolved by ARPES experiments. These bands are characterized by small superconducting gaps with an average zero-temperature value of Delta(0) = 2.4(2) meV. Our data suggest that in CaKFe4As4 the s(perpendicular to) order parameter symmetry acquires a more sophisticated form by allowing a sign change not only between electron and hole pockets, but also within pockets of similar type.

Language

en

Department of Energy Subject Categories

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Publisher

Iowa State University Digital Repository, Ames IA (United States)

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