Pauli paramagnetic effects on mixed-state properties in a strongly anisotropic superconductor: Application to Sr2RuO4
Pauli paramagnetic effects on mixed-state properties in a strongly anisotropic superconductor: Application to Sr2RuO4
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DOI：
10.1103/physrevb.91.144513
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发表时间：
2015-04
影响因子：
3.7
通讯作者：
Y. Amano;M. Ishihara;M. Ichioka;N. Nakai;K. Machida
中科院分区：
文献类型：
--
作者：
Y. Amano;M. Ishihara;M. Ichioka;N. Nakai;K. Machida
我们从理论上研究了具有泡利顺磁效应的强单轴各向异性 II 型超导体的混合态特性，重点研究了当磁场方向从传导层 ab 平面倾斜时它们的行为。在艾伦伯格理论的基础上，我们定量估计了泡利顺磁效应对各种物理可观测值的显着贡献，包括磁通线晶格形状因子的横向和纵向分量、磁化曲线、索末菲系数、场分布和磁矩。我们将这些研究应用于Sr_2_RuO_4_并定量解释了一些看似奇怪的行为，包括ab平面方向的H_c2_抑制、自旋翻转小角度中子散射发现的较大各向异性比和强度，以及最近在磁热、比热和磁化测量中以连贯一致的方式观察到的一阶跃迁。这些使我们得出结论，Sr_2_RuO_4_ 是与 ab 平面中的 d 向量分量配对的自旋单线态或自旋三线态。
We study theoretically the mixed state properties of a strong uniaxially-anisotropic type II superconductor with the Pauli paramagnetic effect, focusing on their behaviors when the magnetic field orientation is tilted from the conduction layer ab plane. On the basis of Eilenberger theory, we quantitatively estimate significant contributions of the Pauli paramagnetic effects on a variety of physical observables, including transverse and longitudinal components of the flux line lattice form factors, magnetization curves, Sommerfeld coefficient, field distributions and magnetic torques. We apply these studies to Sr_2_RuO_4_ and quantitatively explain several seemingly curious behaviors, including the H_c2_ suppression for the ab plane direction, the larger anisotropy ratio and intensity found by the spin-flip small angle neutron scattering, and the first order transition observed recently in magneto-caloric, specific heat and magnetization measurements in a coherent and consistent manner. Those lead us to conclude that Sr_2_RuO_4_ is either a spin-singlet or a spin-triplet pairing with the d-vector components in the ab plane.