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Comparative analysis of specific heat of YNi2B2C using nodal and two-gap models

C. L. Huang·J. Y. Lin·C. P. Sun·T. K. Lee·J. D. Kim·E. M. Choi·S. I. Lee·H. D. Yang
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Abstract

The magnetic field dependence of low temperature specific heat in YNi2B2C was measured and analyzed using various pairing order parameters. At zero magnetic field, the two-gap model which has been successfully applied to MgB2 and the point-node model, appear to describe the superconducting gap function of YNi2B2C better than other models based on the isotropic s-wave, the d-wave line nodes, or the s+g wave. The two energy gaps, delta_L=2.67 meV and delta_S=1.19 meV are obtained. The observed nonlinear field dependence of electronic specific heat coefficient, gamma(H)~H0.47, is quantitatively close to gamma(H)~H0.5 expected for nodal superconductivity or can be qualitatively explained using two-gap scenario. Furthermore, the positive curvature in Hc2(T) near Tc is qualitatively similar to that in the other two-gap superconductor MgB2.

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C. L. Huang, J. Y. Lin, C. P. Sun, T. K. Lee, J. D. Kim, E. M. Choi, S. I. Lee, H. D. Yang. 2005-12-14. Comparative analysis of specific heat of YNi2B2C using nodal and two-gap models. https://doi.org/10.1103/physrevb.73.012502

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