Calorimetric evidence of strong-coupling multiband superconductivity in Fe(Te0.57Se0.43) single crystal

2011/03/15 by J. Hu, Jin Hu, T. J. Liu +8
Materials Science · Physics and Astronomy · #Chalcogenide #Condensed matter physics #Coupling (piping) #Heat capacity #Iron-based superconductors research #Materials science #Optoelectronics #Physics #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #Specific heat #Superconductivity #Thermodynamics #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.83.134521

published as Phys. Rev. B 83, 134521 (2011)

arxiv created 2011/03/15 · openalex publication_date 2011/04/27 · arxiv updated 2011/04/29 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

We have investigated the specific heat of optimally doped iron chalcogenide superconductor Fe(Te_0.57Se_0.43) with a high-quality single crystal sample. The electronic specific heat C_e of this sample has been successfully separated from the phonon contribution using the specific heat of a nonsuperconducting sample (Fe_0.90Cu_0.10)(Te_0.57Se_0.43) as a reference. The normal-state Sommerfeld coefficient \ensuremathγ_n of the superconducting sample is found to be ~26.6 mJ/mol K², indicating intermediate electronic correlation. The temperature dependence of C_e in the superconducting state can be best fitted using a double-gap model with 2\ensuremathΔ_s(0)/k_BT_c=3.92 and 2\ensuremathΔ_l(0)/k_BT_c=5.84. The large gap magnitudes derived from fitting, as well as the large specific heat jump of \ensuremathΔC_e(T_c)/\ensuremathγ_nT_c~2.11, indicate strong-coupling superconductivity. Furthermore, the magnetic field dependence of specific heat shows strong evidence for multiband superconductivity.

Citations

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