arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.03904cond-mat.str-el
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强关联电子系统实际模型中的极化子变换

Polaron transformations in the realistic model of the strongly correlated electron system

E. I. Shneyder, S. V. Nikolaev, M. V. Zotova, R. A. Kaldin, S. G. Ovchinnikov

摘要:

电子-声子耦合,对角线在一个真正的空间制定,导致极化子范例的平稳变化的属性。然而,当考虑非对角配对时,极化子的奇异行为发生了根本性的变化。极化子变换和物质相关性质的研究对现实模型特别有意义,因为在其他强相互作用存在下,对角和非对角电子-声子贡献之间的竞争可能导致系统的非常规行为。本文考虑了具有电子-声子相互作用的铜酸盐超导体的多带pd模型,分析了在强电子关联极限下,对角和非对角电子-声子贡献的竞争所引起的系统特性。利用极化子形式的广义紧束缚方法,我们描述了从绝热极限的弱耦合强度到强耦合强度的电子-声子参数空间中的能带结构、费米面、费米能级态密度和声子谱函数的演化.在极化子性质的相图上,我们揭示了两个量子相变,并显示了电子-声子相互作用如何引起费米表面的转变(i)从空穴袋到费米弧和(ii)从空穴到电子类型的导电性。我们还证明了新的状态的出现在声子谱函数的极化子,并讨论了它们的起源。

英文摘要:

Electron-phonon coupling, diagonal in a real space formulation, leads to polaron paradigm of smoothly varying properties. However, fundamental changes, namely the singular behavior of polarons, occur if non-diagonal pairing is involved into consideration. The study of polaron transformations and related properties of matter is of particular interest for realistic models, since competition between diagonal and non-diagonal electron-phonon contributions in the presence of other strong interactions can result in unconventional behavior of the system. Here we consider the multiband pd-model of cuprate superconductors with electron-phonon interaction and analyze the features of the systems that are caused by the competition of diagonal and non-diagonal electron-phonon contributions in the limit of strong electron correlations. Using the polaronic version of the generalized tight-binding method, we describe the evolution of the band structure, Fermi surface, density of states at Fermi level, and phonon spectral function in the space of electron-phonon parameters ranging from weak to strong coupling strength of the adiabatic limit. On the phase diagram of polaron properties we reveal two quantum phase transitions and show how electron-phonon interaction gives rise to Fermi surface transformation (i) from hole pockets to Fermi arcs and (ii) from hole to electron type of conductivity. We also demonstrate the emergence of new states in the phonon spectral function of the polaron and discuss their origin.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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