Roles of Multipoles and Excitons in Superconductor PrOs4Sb12 with Th Symmetry
Roles of Multipoles and Excitons in Superconductor PrOs4Sb12 with Th Symmetry
复制标题
DOI：
10.1143/jpsj.75.014709
复制
发表时间：
2006-01
影响因子：
1.7
通讯作者：
M. Koga;M. Matsumoto;H. Shiba
中科院分区：
文献类型：
--
作者：
M. Koga;M. Matsumoto;H. Shiba
研究了Pr方钴矿PrOs4Sb12超导体的超导电性，并讨论了其可能的激子介导机制.在该化合物中，Pr的低位晶场态形成了由τ 1单重态基态和τ 4（2）三重态激发态组成的伪四重态。色散晶体场激发（激子）已被实验检测到。传导电子与赝四重态磁性和非磁性耦合。我们相信这种耦合对于PrOs 4 Sb 12的各种性质至关重要，因此我们确定了导电电子与Pr伪四重态之间的有效相互作用。事实证明，交换过程的性质与传导电子的a u和t u分量密切相关，这些分量对应于Pr离子周围的Sb 12笼的分子轨道。通过交换耦合中的二级微扰，导出了单重态和三重态超导体中的库珀配对相互作用。首先，它们是类…
A possibility of exciton-mediated mechanism is studied to describe the superconductivity in a Pr skutterudite PrOs 4 Sb 12 . In this compound the low-lying crystal-field states of Pr form a pseudo-quartet consisting of Γ 1 singlet ground and Γ 4 (2) triplet excited states. The dispersive crystal-field excitations (excitons) have been detected experimentally. The conduction electrons couple both magnetically and nonmagnetically with the pseudo-quartet. Believing that this coupling should be crucial for various properties of PrOs 4 Sb 12 , we determine the effective interaction between conduction electrons and the Pr pseudo-quartet states. It turns out that the nature of exchange processes is related closely to a u and t u components of the conduction electrons that correspond to the molecular orbitals of an Sb 12 cage surrounding a Pr ion. By the second-order perturbation in the exchange coupling, Cooper pairing interactions are derived both for singlet and triplet superconductivities. First, they are clas...