论文标题
自旋和电荷相关性之间的非扰动交织:“吸烟枪”单验交换结果
Non-perturbative intertwining between spin and charge correlations: A "smoking gun" single-boson-exchange result
论文作者
论文摘要
我们通过对几种基本多电子模型的广义现场电荷敏感性进行彻底研究,研究了相关电子系统中局部电荷与局部自旋波动之间相互作用的微观机制,例如Hubbard Atom,Anderson Mighity杂质模型以及Hubbard模型。通过在物理上透明的单个验交换过程方面分解数值确定的广义易感性,我们揭示了负责自我持续的多电子扰动扩展的微观机制。特别是,我们明确地确定了对(Matsubara)频率空间(Matsubara)频率空间中对角条目的显着抑制的起源,以及导致崩溃的异性抗线作用的略有增加。对角元件的抑制作用直接源自局部磁矩上的电子散射,反映了它们越来越长的寿命以及增强的有效耦合与电子的耦合。取而代之的是,偏离术语的轻微和分散的增强大部分可以归因于多体散射过程。由于在低频状态下,自旋和电荷扇区之间的强相互交织部分在近藤温度下部分削弱了局部磁波的有效自旋效力耦合。因此,我们的分析阐明了在相互作用的电子问题的不同散射通道之间传递物理信息的确切机制,并突出了这种相互交织在扰动状态以外的相关电子物理学中所起的关键作用。
We study the microscopic mechanism controlling the interplay between local charge and local spin fluctuations in correlated electron systems via a thorough investigation of the generalized on-site charge susceptibility of several fundamental many-electron models, such as the Hubbard atom, the Anderson impurity model, and the Hubbard model. By decomposing the numerically determined generalized susceptibility in terms of physically transparent single-boson exchange processes, we unveil the microscopic mechanisms responsible for the breakdown of the self-consistent many-electron perturbation expansion. In particular, we unambiguously identify the origin of the significant suppression of its diagonal entries in (Matsubara) frequency space and the slight increase of the off-diagonal ones which cause the breakdown. The suppression effect on the diagonal elements originates directly from the electronic scattering on local magnetic moments, reflecting their increasingly longer lifetime as well as their enhanced effective coupling with the electrons. Instead, the slight and diffuse enhancement of the off-diagonal terms can be mostly ascribed to multiboson scattering processes. The strong intertwining between spin and charge sectors is partly weakened at the Kondo temperature due to a progressive reduction of the effective spin-fermion coupling of local magnetic fluctuations in the low frequency regime. Our analysis, thus, clarifies the precise mechanism through which the physical information is transferred between different scattering channels of interacting electron problems and highlights the pivotal role played by such an intertwining in the physics of correlated electrons beyond the perturbative regime.