Microscopic theory of the superconducting gap in the quasi-one-dimensional organic conductor (TMTSF)2ClO4: Model derivation and two-particle self-consistent analysis
Microscopic theory of the superconducting gap in the quasi-one-dimensional organic conductor (TMTSF)2ClO4: Model derivation and two-particle self-consistent analysis
复制标题
准一维有机导体（TMTSF）2ClO4中超导能隙的微观理论：模型推导和双粒子自洽分析
DOI：
10.1103/physrevb.97.104507
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发表时间：
2018
影响因子：
3.7
通讯作者：
and Kazuhiko Kuroki
中科院分区：
文献类型：
--
作者：
Hirohito Aizawa;and Kazuhiko Kuroki
给出了准一维(Q1D)有机超导体的第一原理能带计算。基于最大定域Wannier轨道的计算，得到了一个以TMTSF分子为中心的有效紧束缚模型。我们采用了一个四点Hubbard模型进行两粒子自洽(TPSC)分析，该模型由紧束缚模型和作为变量参数的在位(分子内)排斥相互作用组成。我们假设配对机制是由自旋涨落介导的，并且内、外费米面之间的超导能隙符号发生变化，这与简化的Q1D模型中的a波能隙函数相对应。在我们采用的参数下，用TPSC方法估算的超导临界温度约为1K，这与实验结果一致。
We present a first-principles band calculation for the quasi-one-dimensional (Q1D) organic superconductor. An effective tight-binding model with the TMTSF molecule to be regarded as the site is derived from a calculation based on maximally localized Wannier orbitals. We apply a two-particle self-consistent (TPSC) analysis by using a four-site Hubbard model, which is composed of the tight-binding model and an onsite (intramolecular) repulsive interaction, which serves as a variable parameter. We assume that the pairing mechanism is mediated by the spin fluctuation, and the sign of the superconducting gap changes between the inner and outer Fermi surfaces, which correspond to a-wave gap function in a simplified Q1D model. With the parameters we adopt, the critical temperature for superconductivity estimated by the TPSC approach is approximately 1 K, which is consistent with experiment.