Evidence for Eight-Node Mixed-Symmetry Superconductivity in a Correlated Organic Metal.
Evidence for Eight-Node Mixed-Symmetry Superconductivity in a Correlated Organic Metal.
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DOI：
10.1103/physrevlett.116.237001
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发表时间：
2015-10
影响因子：
8.6
通讯作者：
D. Guterding;Sandra Diehl;M. Altmeyer;T. Methfessel;U. Tutsch;H. Schubert;M. Lang;J. Müller;M. Huth;H. Jeschke;R. Valentí;M. Jourdan;H. Elmers
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文献类型：
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作者：
D. Guterding;Sandra Diehl;M. Altmeyer;T. Methfessel;U. Tutsch;H. Schubert;M. Lang;J. Müller;M. Huth;H. Jeschke;R. Valentí;M. Jourdan;H. Elmers
本文报道了准二维有机超导体κ-（ET）_{2}Cu[N（CN）_{2}]Br的超导态的理论和实验研究。将自旋涨落理论应用于从从头算密度泛函理论导出的低能、特定于材料的哈密顿量，我们计算了超导态的准粒子态密度。我们发现一个明显的三峰结构，结果从一个强各向异性的混合对称超导带隙的八个节点和双重旋转对称。低温扫描隧道谱（SEM）结果表明，K-（ET）_{2}Cu[N（CN）_{2}]Br晶体的隧穿方向平行于层状结构。
We report on a combined theoretical and experimental investigation of the superconducting state in the quasi-two-dimensional organic superconductor κ-(ET)_{2}Cu[N(CN)_{2}]Br. Applying spin-fluctuation theory to a low-energy, material-specific Hamiltonian derived from ab initio density functional theory we calculate the quasiparticle density of states in the superconducting state. We find a distinct three-peak structure that results from a strongly anisotropic mixed-symmetry superconducting gap with eight nodes and twofold rotational symmetry. This theoretical prediction is supported by low-temperature scanning tunneling spectroscopy on in situ cleaved single crystals of κ-(ET)_{2}Cu[N(CN)_{2}]Br with the tunneling direction parallel to the layered structure.