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arXiv · 1002.4846

Electronic correlations and unusual superconducting response in the optical properties of the iron-chalcogenide FeTe0.55Se0.45

C. C. Homes·A. Akrap·J. S. Wen·Z. J. Xu·Z. W. Lin·Q. Li·G. D. Gu
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Abstract

The in-plane complex optical properties of the iron-chalcogenide superconductor FeTe0.55Se0.45 have been determined above and below the critical temperature Tc = 14 K. At room temperature the conductivity is described by a weakly-interacting Fermi liquid; however, below 100 K the scattering rate develops a frequency dependence in the terahertz region, signaling the increasingly correlated nature of this material. We estimate the dc conductivity just above Tc to be sigma_dc ~ 3500 Ohm-1cm-1 and the superfluid density rho_s0 ~ 9 x 10^6 cm-2, which places this material close to the scaling line rho_s0/8 ~ 8.1 sigma_dc Tc for a BCS dirty-limit superconductor. Below Tc the optical conductivity reveals two gap features at Delta_1,2 ~ 2.5 and ~ 5.1 meV.

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C. C. Homes, A. Akrap, J. S. Wen, Z. J. Xu, Z. W. Lin, Q. Li, G. D. Gu. 2010-02-25. Electronic correlations and unusual superconducting response in the optical properties of the iron-chalcogenide FeTe0.55Se0.45. https://doi.org/10.1103/physrevb.81.180508

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