论文标题
重新审视超导体中的杂质散射
Impurity scattering in superconductors revisited
论文作者
论文摘要
图表形式主义和传输方程通常被认为是解决杂质散射效果的独立但互补的技术。与先前的研究量规动力学方程方法进行比较[F. Yang和M. W. Wu，物理。 Rev. B 98，094507（2018）; 102，144508（2020）]，我们在分析上对超导体中的杂质散射进行了示意图，并研究了运输和集体的希格斯模式，以填补库波电流电流的长期计算，无论是在不散射和散布的模式下，超级导向的超导相关性是否会导致效率（无论是在不散射）的模式（无论是在不散发的模式）仪表不变的动力学方程和Eilenberger方程。对于运输行为，通过特殊的统一转换，等同于Wilson-Line技术的Dimagnetic响应，我们得出了Meissner-Supercurrent顶点。然后，通过与杂质散射的出生和顶点校正的超电流 - 旋流相关性，我们通过仪表不变的动力学方程恢复了先前揭示的超氟化体的微观动量 - 释放速率。只有当超导速度大于阈值时，这种速率才有限，在这种阈值中，正常流体出现并用超流体电流引起摩擦，类似于Landau的液态氦的超流体理论。这种推导还提供了对文献中先前的示意图中放松时间近似的物理理解，这导致了Meissner Supercurrent的摩擦抗性。对于集体HIGGS模式，我们计算出与杂质散射中的出生和顶点校正的振幅振幅相关性。顶点校正仅在非平衡情况下出现，导致Higgs模式阻尼，.....
The diagrammatic formalism and transport equation are conventionally considered as separate but complementary techniques to tackle the impurity scattering effect. To compare with the previous studies from the gauge-invariant kinetic equation approach [F. Yang and M. W. Wu, Phys. Rev. B 98, 094507 (2018); 102, 144508 (2020)], we analytically perform a diagrammatic formulation of the impurity scattering in superconductors, with both transport and collective Higgs mode studied, in order to fill the long missing calculation of the Kubo current-current correlation in superconductors with impurity scattering and resolve the controversy (whether the impurity scattering can lead to the damping of Higgs mode) between gauge-invariant kinetic equation and Eilenberger equation. For transport behavior, through a special unitary transformation that is equivalent to the Wilson-line technique for the diamagnetic response, we derive the Meissner-supercurrent vertex. Then, by formulating the supercurrent-supercurrent correlation with Born and vertex corrections from impurity scattering, we recover the previously revealed microscopic momentum-relaxation rate of superfluid by gauge-invariant kinetic equation. This rate is finite only when the superconducting velocity is larger than a threshold, at which the normal fluid emerges and causes the friction with the superfluid current, similar to the Landau's superfluid theory of liquid helium. This derivation also provides a physical understanding of the relaxation-time approximation in the previous diagrammatic formulation in the literature, which leads to the friction resistance of the Meissner supercurrent. For the collective Higgs mode, we calculate the amplitude-amplitude correlation with Born and vertex corrections from impurity scattering. The vertex correction, which only emerges at nonequilibrium case, leads to a Higgs-mode damping, ......
