Evidence of d-wave superconductivity in K1-xNaxFe2As2 (x=0,0.1) single crystals from low-temperature specific-heat measurements
Evidence of d-wave superconductivity in K1-xNaxFe2As2 (x=0,0.1) single crystals from low-temperature specific-heat measurements
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DOI：
10.1103/physrevb.87.180507
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发表时间：
2013-01
影响因子：
3.7
通讯作者：
Mahmoud Abdel-Hafiez;Vadim Grinenko;S. Aswartham;I. Morozov;M. Roslova;O. Vakaliuk;Steven Johnston;D. Efremov;J. Brink;H. Rosner;Manoj Kumar;Christian Hess;S. Wurmehl;A. Wolter;B. Büchner;E. Green;J. Wosnitza;P. Vogt;A. Reifenberger;C. Enss;M. Hempel;R. Klingeler;S. Drechsler
中科院分区：
文献类型：
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作者：
Mahmoud Abdel-Hafiez;Vadim Grinenko;S. Aswartham;I. Morozov;M. Roslova;O. Vakaliuk;Steven Johnston;D. Efremov;J. Brink;H. Rosner;Manoj Kumar;Christian Hess;S. Wurmehl;A. Wolter;B. Büchner;E. Green;J. Wosnitza;P. Vogt;A. Reifenberger;C. Enss;M. Hempel;R. Klingeler;S. Drechsler
通过对高质量的K_(1-x)Na_xFe_2As_2单晶比热的测量和分析，我们确定了在x=0和0.1的低T下，存在大的T^2贡献，其系数α_sc~30mJ/molK^3。结合观察到的超导态比热的平方根场行为，这两个发现都证明了几乎所有的费米面片上都存在d波超导，平均能隙幅度在0.4-0.8 meV范围内。导出的Delta_0和观测到的T_c与Eliashberg理论的计算值符合得很好，在中间耦合区域采用了自旋涨落介导的配对。
From the measurement and analysis of the specific heat of high-quality K_(1-x)Na_xFe_2As_2 single crystals we establish the presence of large T^2 contributions with coefficients alpha_sc ~ 30 mJ/mol K^3 at low-T for both x=0 and 0.1. Together with the observed square root field behavior of the specific heat in the superconducting state both findings evidence d-wave superconductivity on almost all Fermi surface sheets with an average gap amplitude of Delta_0 in the range of 0.4 - 0.8 meV. The derived Delta_0 and the observed T_c agree well with the values calculated within the Eliashberg theory, adopting a spin-fluctuation mediated pairing in the intermediate coupling regime.