论文标题
根尖氧振动在D波库酸酯超导性中主要作用及其与自旋波动的相互作用
Apical oxygen vibrations dominant role in d-wave cuprate superconductivity and its interplay with spin fluctuations
论文作者
论文摘要
高TC Cuprate Bisco的微观理论基于CuO平面中电子的主要配对通道，这是由于SRO离子绝缘子层的40mev侧向氧原子的40mev横向振动。振动带电原子与2D电子气体之间的分离产生了前向散射峰，又导致Eliashberg形式主义内的D波配对。声子模式自然解释了ARPE观察到的分散关系中的扭结以及O16与O18同位素在正常状态下的扭结。为了描述伪gap物理，单个频带四倍对称哈伯德模型，带有跳跃参数t'= -0.17t，并且使用了位点抑制u = 6T。它描述了低掺杂的莫特绝缘子，而在较高的pseudogap物理学（仍然密切相关）的情况下，可以通过对称的平均场模型近似，并且随着重新归一化的U型U型筛选。在此近似值中，还获得了局部抗铁磁pseudogap和顺磁性过高的相位和敏感性（描述自旋含量偶联偶联的旋转含量）之间的过渡线的位置。超导D波间隙主要是由于声子通道引起的，但受自旋波动的辅助（15-20％）。 GAP和TC对同位素取代的掺杂和影响的依赖性与实验一致。
Microscopic theory of a high Tc cuprate BiSCO based on main pairing channel of electrons in CuO planes due to 40meV lateral vibrations of the apical oxygen atoms in adjacent the SrO ionic insulator layer is proposed. The separation between the vibrating charged atoms and the 2D electron gas creates the forward scattering peak leading in turn to the d-wave pairing within Eliashberg formalism. The phonon mode naturally explain the kink in dispersion relation observed by ARPES and the and effect of the O16 to O18 isotope substitution in the normal state. To describe the pseudogap physics a single band fourfold symmetric Hubbard model, with the hopping parameters t' = - 0.17t and the on site repulsion U = 6t was used. It described the Mott insulator at low doping, while at higher dopping the pseudogap physics (still strongly correlated) can be be approximated by the symmetrized mean field model and with renormalized U incorporating screening. The location of the transition line between the locally antiferromagnetic pseudogap and the paramagnetic overdoped phases and susceptibility (describing spin uctuations coupling to 2DEG) are also obtained within this approximation. The superconducting d-wave gap mainly due to the phonon channel but is assisted by the spin fluctuations (15-20%). The dependence of the gap and Tc on doping and effect of the isotope substitution are obtained and is consistent with experiments.
