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arXiv · 1109.0554

Volovik effect in a highly anisotropic multiband superconductor: experiment and theory

Y. Wang·J. S. Kim·G. R. Stewart·P. J. Hirschfeld·S. Graser·S. Kasahara·T. Terashima·Y. Matsuda·T. Shibauchi·I. Vekhter
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Abstract

We present measurements of the specific heat coefficient γ(= C/T) in the low temperature limit as a function of an applied magnetic field for the Fe-based superconductor BaFe$_2$(As$_{0.7}$P$_{0.3}$)$_2$. We find both a linear regime at higher fields and a limiting square root $H$ behavior at very low fields. The crossover from a Volovik-like $\sqrt{H}$ to a linear field dependence can be understood from a multiband calculation in the quasiclassical approximation assuming gaps with different momentum dependence on the hole- and electron-like Fermi surface sheets.

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Y. Wang, J. S. Kim, G. R. Stewart, P. J. Hirschfeld, S. Graser, S. Kasahara, T. Terashima, Y. Matsuda, T. Shibauchi, I. Vekhter. 2011-09-02. Volovik effect in a highly anisotropic multiband superconductor: experiment and theory. https://doi.org/10.1103/physrevb.84.184524

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