Specific Heat in High Magnetic Fields of BaFe$_{\mathrm{2}}$(As$_{\mathrm{1-x}}$P$_{\mathrm{x}})_{\mathrm{2}}$

ORAL

Abstract

We measure the magnetic field dependence of the specific heat in BaFe$_{\mathrm{2}}$(As$_{\mathrm{1-x}}$P$_{\mathrm{x}})_{\mathrm{2}}$ with x ranging from x$=$0.31 to x$=$0.6 in fields up to 34.5T. We report three important observations: $\surd $H behavior indicating a nodal superconducting gap with a linear energy dispersion, saturation of the heat capacity at the magnetic field that corresponds to the resistive onset [1], and a calculated quasiparticle mass using the increase in the electronic specific heat coefficient when entering the normal state, $\Delta \gamma $ $= \quad \gamma $(34.5T) -- $\gamma $(0T), as a measure of the normal state specific heat. [1] James G. Analytis, H-H. Kuo, Ross D. McDonald, Mark Wartenbe, P. M. C. Rourke, N. E. Hussey {\&} I. R. Fisher. \textit{Nature Phys}. 10, 194--197 (2014)

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Authors

  • Camilla M. Moir

    FSU/NHMFL

  • Jose A. Galvis

    National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA, NHMFL

  • Phillip Walmsley

    Stanford University, Stanford

  • James G. Analytis

    UC Berkeley, University of California, Berkeley, CA, USA

  • Jiun-Haw Chu

    Stanford

  • Ian R. Fisher

    Department of Applied Physics and Geballe Laboratory for Advanced Materials Stanford University, Stanford University, Stanford

  • Arkady Shekhter

    National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA, NHMFL

  • Greg S. Boebinger

    National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA, FSU/NHMFL

  • Scott C. Riggs

    NHMFL-FSU, National High Magnetic Field Laboratory, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA, NHMFL