论文标题
杂质对库酸酯超导体中电子结构的影响
Influence of impurities on electronic structure in cuprate superconductors
论文作者
论文摘要
这种杂质在铜酸盐超导体中固有地表现出来，因为阳离子的取代或插入是引入电荷载体所必需的，并且其对电子状态的影响是物理学上一场巨大辩论的核心。在这里，基于微观八位格散射模型，根据自洽的T-矩阵方法研究了杂质散射对库酸酯超导体电子结构的影响。 The impurity scattering self-energy is evaluated firstly in the Fermi-arc-tip approximation of the quasiparticle excitations and scattering processes, and the obtained results show that the decisive role played by the impurity scattering self-energy in the particle-hole channel is the further renormalization of the quasiparticle band structure with a reduced quasiparticle lifetime, while the impurity scattering self-energy in the particle-particle通道引起了与超导间隙的D波行为的强偏差，从而导致在整个电子费米表面上存在有限的间隙。此外，这些杂质散射的自我能量被用来研究准粒子激发光谱中线形的外来特征和准粒子激发光谱的自相关，然后将获得的结果与相应的实验数据进行比较。因此，该理论还表明，库酸酯超导体中电子结构的非常规特征是由强电子相关性和杂质散射产生的。
The impurity is inherently manifest in cuprate superconductors, as cation substitution or intercalation is necessary for the introduction of charge carriers, and its influence on the electronic state is at the heart of a great debate in physics. Here based on the microscopic octet scattering model, the influence of the impurity scattering on the electronic structure of cuprate superconductors is investigated in terms of the self-consistent T-matrix approach. The impurity scattering self-energy is evaluated firstly in the Fermi-arc-tip approximation of the quasiparticle excitations and scattering processes, and the obtained results show that the decisive role played by the impurity scattering self-energy in the particle-hole channel is the further renormalization of the quasiparticle band structure with a reduced quasiparticle lifetime, while the impurity scattering self-energy in the particle-particle channel induces a strong deviation from the d-wave behaviour of the superconducting gap, leading to the existence of a finite gap over the entire electron Fermi surface. Moreover, these impurity scattering self-energies are employed to study the exotic features of the line-shape in the quasiparticle excitation spectrum and the autocorrelation of the quasiparticle excitation spectra, and the obtained results are then compared with the corresponding experimental data. The theory therefore also indicates that the unconventional features of the electronic structure in cuprate superconductors is generated by both the strong electron correlation and impurity scattering.
