Point contact Andreev reflection spectroscopy of superconducting energy gaps in 122-type family of iron pnictides

TitlePoint contact Andreev reflection spectroscopy of superconducting energy gaps in 122-type family of iron pnictides
Publication TypeJournal Article
Year of Publication2009
AuthorsSamuely P, Pribulova Z, Szabo P, Pristas G, Bud'ko SL, Canfield PC
Journal TitlePhysica C-Superconductivity and Its Applications
Volume469
Pages507-511
Date Published05/01
ISBN Number0921-4534
Accession NumberISI:000267191500025
Keywords122-type iron pnictides, ba0.6k0.4fe2as2, resolved photoemission-spectroscopy, superconducting energy gaps
Abstract

A brief overview of the superconducting energy gap studies on 122-type family of iron pnictides is given. It seems that the situation in the hole doped Ba1-xKxFe2As2 is well resolved. Most of the measurements including the presented here point contact Andreev reflection spectra agree on existence of multiple nodeless gaps in the excitation spectrum of this multiband system. The gaps have basically two sizes the small one with a strength up to the BCS weak coupling limit and the large one with a very strong coupling with 2 Delta(L)/kT(c) > 6-8. In the electron doped Ba(Fe1-xCox)(2)As-2 the most of the experiments including our point contact measurements reveal in quite broadened spectra only a single gap with a strong coupling strength. The high precision ARPES measurements on this system identified two gaps but very close to each other, both showing a strong coupling with 2 Delta/kT(c) similar to 5 and 6, respectively. (C) 2009 Elsevier B.V. All rights reserved.

URL<Go to ISI>://000267191500025
DOI10.1016/J.Physc.2009.03.037