Unambiguous evidence for nearly isotropic s-wave gap in the bulk of optimally electron-doped Nd_1.85Ce_0.15CuO_4-y

2009/07/12 by Guo-meng Zhao, Zhao, Guo-meng
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.0907.2011

4 pages, 4 figures

arxiv created 2010/03/10 · arxiv updated 2010/03/11

Abstract

We address an important issue as to whether bulk-sensitive data of Raman scattering, optical conductivity, magnetic penetration depth, directional point-contact tunneling spectra, and nonmagnetic pair-breaking effect in optimally electron-doped Nd_1.85Ce_0.15CuO_4-y support a nodeless s-wave or d-wave superconducting gap. We numerically calculate Raman intensities, directional point-contact tunneling spectra, and nonmagnetic pair-breaking effect in terms of both s-wave and d-wave gap symmetries. We find that all these bulk-sensitive data are in quantitative agreement with a nearly isotropic s-wave gap. The fact that T_c is nearly independent of the residual resistivity rules out any d-wave gap symmetry.

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