2009/09/26 by J. K. Dong, Dong, J. K., S. Y. Zhou +17 · 1 citation
Physics and Astronomy · #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.0909.4855
This paper is replaced by arXiv:0910.2806, which includes a detailed study of the quantum criticality in KFe2As2. The paper arXiv:0910.2806 supersedes this paper
arxiv created 2009/10/15 · arxiv updated 2009/12/01
The in-plane resistivity ρ and thermal conductivity κ of extremely overdoped KFe2As2 (Tc = 3.0 K) single crystal were studied. It is found that ρ∼ T1.5 at low temperature, a typical non-Fermi liquid behavior of electrons scattered by antiferromagnetic spin fluctuations. In zero field, we observed a large residual linear term κ0/T, about one third of the normal-state value. In low magnetic fields, κ0/T(H) increases very fast. Such a behavior of κ0/T mimics the d-wave cuprate superconductors, therefore provides clear evidence for nodes in the superconducting gap of KFe2As2. Based on the Fermi surface topology of KFe2As2, it is believed that the dominant intraband pairing via antiferromagnetic spin fluctuations results in the unconventional superconducting gap with nodes.