Campus Units

Physics and Astronomy, Ames Laboratory

Document Type

Article

Publication Version

Published Version

Publication Date

2-12-2010

Journal or Book Title

Physical Review Letters

Volume

104

Issue

6

First Page

067002

DOI

10.1103/PhysRevLett.104.067002

Abstract

The temperature and magnetic field dependence of the in-plane thermal conductivity κ of the iron-arsenide superconductor Ba(Fe1−xCox)2As2 was measured down to T≃50  mK and up to H=15  T as a function of Co concentration x in the range 0.048≤x≤0.114. At H=0, a negligible residual linear term in κ/T as T→0 at all x shows that the superconducting gap has no nodes in the ab plane anywhere in the phase diagram. However, while the slow H dependence of κ(H) at T→0 in the underdoped regime is consistent with a superconducting gap that is large everywhere on the Fermi surface, the rapid increase in κ(H) observed in the overdoped regime shows that the gap acquires a deep minimum somewhere on the Fermi surface. Outside the antiferromagnetic-orthorhombic phase, the superconducting gap structure has a strongly k-dependent amplitude.

Comments

This article is published as Tanatar, M. A., J-Ph Reid, H. Shakeripour, X. G. Luo, N. Doiron-Leyraud, N. Ni, S. L. Bud’Ko, P. C. Canfield, R. Prozorov, and Louis Taillefer. "Doping Dependence of Heat Transport in the Iron-Arsenide Superconductor Ba (Fe 1− x Co x) 2 As 2: From Isotropic to a Strongly k-Dependent Gap Structure." Physical Review Letters 104, no. 6 (2010): 067002. DOI: 10.1103/PhysRevLett.104.067002. Posted with permission.

Copyright Owner

American Physical Society

Language

en

File Format

application/pdf

Included in

Physics Commons

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