Mean-field description of odd-frequency superconductivity with staggered ordering vector
Mean-field description of odd-frequency superconductivity with staggered ordering vector
复制标题
具有交错排序向量的奇频超导性的平均场描述
DOI：
10.1103/physrevb.90.115154
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发表时间：
2014
影响因子：
3.7
通讯作者：
Shintaro Hoshino
中科院分区：
文献类型：
--
作者：
高橋沙央里;李知英;小林慎;幸田尚;及川真実;井上貴美子;小倉淳郎;金児－石野 知子;石野史敏;Shintaro Hoshino
针对两通道近藤晶格中具有交错有序向量的波奇频配对态，构造了低能定点哈密顿量。该有效模型是合理的，因为它再现了动态平均场理论获得的自能的低能行为。延迟效应对于奇频配对至关重要，奇频配对来自传导电子和源自低能局域自旋的赝费米子之间的杂化过程。使用有效哈密顿量，对电磁响应函数进行微观计算。本系统显示出“弱”迈斯纳效应，其中顺磁和反磁部分都有助于迈斯纳核在超导状态下给出小的总抗磁响应。这一特征与普通波 BCS 配对相反，普通波 BCS 配对中只有反磁核在基态下是有限的。奇数频率阶参数的交错性质对于迈斯纳核的符号起着重要作用。
A low-energy fixed-point Hamiltonian is constructed for the-wave odd-frequency pairing state with staggered ordering vector in the two-channel Kondo lattice. The effective model is justified because it reproduces low-energy behaviors of self-energy obtained by the dynamical mean-field theory. The retardation effect is essential for the odd-frequency pairing, which comes from the hybridization process between conduction electrons and pseudofermions originating from localized spins at low energies. Using the effective Hamiltonian, the electromagnetic response functions are microscopically calculated. The present system shows a “weak” Meissner effect, where both paramagnetic and diamagnetic parts contribute to the Meissner kernel to give a small total diamagnetic response in the superconducting state. This feature is in contrast to the ordinary-wave BCS pairing where only the diamagnetic kernel is finite in the ground state. The staggered nature of the odd-frequency order parameter plays an important role for the sign of the Meissner kernel.