Evidence for two gaps from specific heat in LiFeAs single crystals

ORAL

Abstract

The mechanism and the paring state of the newly discovered FeAs based superconductors are still open questions. We report here the specific heat of several single crystals of LiFeAs from 1.8K to 160K. The Cp anomaly around the transition temperature Tc = 17 K is clear, and a change of the slope d(Cp/T)/dT$^{2}$ is observed around 4 K. This down turn in the Cp/T vs. T$^{2}$ plot, however, is suppressed in both poly-crystal samples and under high fields. We attribute this feature to the second gap, and will compare the data with calculations.

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Authors

  • Fengyan Wei

    • Texas Center for Superconductivity at University of Houston and Department of Physics

  • Bing Lv

    • Texas Center for Superconductivity at University of Houston and Department of Chemistry

  • Feng Chen

    • Texas Center for Superconductivity at University of Houston and Department of Physics

  • Yuyi Xue

    • Texas Center for Superconductivity at University of Houston and Department of Physics

  • Arnold M. Guloy

    • Texas Center for Superconductivity at University of Houston and Department of Chemistry

  • Chingwu Chu

    • Texas Center for Superconductivity at Universtiy of Houston, Lawrence Berkeley National Laboratory, Hong Kong University of Science and Technology