Possible spin-triplet f-wave pairing due to disconnected Fermi surfaces in NaxCoO2•yH2O -: art. no. 077001
Possible spin-triplet f-wave pairing due to disconnected Fermi surfaces in NaxCoO2•yH2O -: art. no. 077001
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DOI：
10.1103/physrevlett.93.077001
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发表时间：
2004-08-13
影响因子：
8.6
通讯作者：
Arita, R
中科院分区：
文献类型：
--
作者：
Kuroki, K;Tanaka, Y;Arita, R
我们提出在我们之前的研究中提出的由断开费米面引起的自旋三重态配对机制[Phys]。可能在最近发现的超导体NaxCoO2.yH(2)O中起作用。我们引入了一个单波段有效模型，该模型考虑了在波段计算结果中发现的袋状费米面和K点附近的van Hove奇点。应用涨落交换方法并求解线性化的Eliashberg方程，发现最主要的配对具有自旋三重态f波对称性，其中间隙函数的节点不与袋状费米曲面相交。有限T-c的存在与间隙节点与费米曲面相交的情况形成鲜明对比。
We propose that the spin-triplet pairing mechanism due to disconnected Fermi surfaces proposed in our previous study [Phys. Rev. B 63, 174507 (2001)] may be at work in a recently discovered superconductor NaxCoO2.yH(2)O. We introduce a single band effective model that takes into account the pocketlike Fermi surfaces along with the van Hove singularity near the K point found in the band calculation results. Applying the fluctuation exchange method and solving the linearized Eliashberg equation, the most dominant pairing is found to have spin-triplet f-wave symmetry, where the nodes of the gap function do not intersect the pocket Fermi surfaces. The presence of finite T-c is suggested in sharp contrast to cases when the gap nodes intersect the Fermi surface.