Superconductivity due to charge fluctuation in θ-type organic conductors
Superconductivity due to charge fluctuation in θ-type organic conductors
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DOI：
10.1143/jpsj.73.2053
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发表时间：
2004-08
影响因子：
1.7
通讯作者：
Y. Tanaka;Y. Yanase;M. Ogata
中科院分区：
文献类型：
--
作者：
Y. Tanaka;Y. Yanase;M. Ogata
研究了准二维3/4填充有机化合物中θ型结构的超导电性。在无规相位近似下，计算了各向异性三角晶格上同时存在在位（U）和位间（V）库仑相互作用的相应扩展Hubbard模型的自旋和电荷涨落效应.发现自旋和电荷涨落都诱导了具有扩展的s波单重对的超导电性，这类似于正方形晶格中的d x y对对态。在电荷密度波不稳定性附近，由于最近邻库仑相互作用的影响，f波三重态配对也是稳定的。超导电性和电荷密度波相界的温度依赖性也进行了研究。
Superconductivity close to charge ordering in quasi-two-dimensional 3/4-filled organic compounds is investigated for the θ-type structure. The effect of spin and charge fluctuations is calculated within random phase approximation for a relevant extended Hubbard model with both on-site ( U ) and intersite ( V ) Coulomb interactions on an anisotropic triangular lattice. It is found that both spin and charge fluctuations induce superconductivity with extended s -wave singlet pairing, which is similar to the d x y pairing state in the square lattice. In the vicinity of charge-density-wave instability, f -wave triplet pairing is also stable due to the effect of nearest-neighbor Coulomb interaction. The temperature dependences of superconductivity and charge-density-wave phase boundaries are also examined.