Test for pairing symmetry based on spin fluctuations in the organic superconductor kappa-(BEDT-TTF)2X.
Test for pairing symmetry based on spin fluctuations in the organic superconductor kappa-(BEDT-TTF)2X.
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DOI：
10.1103/physrevlett.91.037002
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发表时间：
2002-11
影响因子：
8.6
通讯作者：
Jian-xin Li
中科院分区：
文献类型：
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作者：
Jian-xin Li
我们提出了有机超导体kappa-(BEDT-TTF)2X的超导对对称性可以通过测量自旋磁化率不相称峰在动量空间中的位置来确定。利用弱耦合BCS理论，并通过哈伯德模型的随机相位近似在各向异性三角形晶格上包含多体效应，我们证明了这些峰的位置是由超导态的配对对称性和费米表面的几何形状唯一决定的。我们证明了d(x（2)-y(2-)）和d（xy）类配对态的自旋响应的不同不相称模式。此外，我们发现在讨论的合理参数范围内不存在自旋共振模式。
We propose that the superconducting pairing symmetry of organic superconductors kappa-(BEDT-TTF)2X can be determined by measuring the position in momentum space of the incommensurate peaks of the spin susceptibility. Using the weak coupling BCS theory and including the many-body effects via the random-phase approximation for the Hubbard model on an anisotropic triangular lattice, we show that the position of these peaks is uniquely determined by the pairing symmetry of the superconducting state and the geometry of the Fermi surface. We demonstrate the different incommensurate patterns of spin responses for d(x(2)-y(2-)) and d(xy)-like pairing states. In addition, we find that there is no spin resonance mode in the reasonable range of parameters discussed.