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arXiv 1504.07569cond-mat.str-el
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莫特绝缘体的第一性原理处理:线性化QSGW + DMFT方法

First-principles treatment of Mott insulators: linearized QSGW+DMFT approach

Sangkook Choi, Andrey Kutepov, Kristjan Haule, Mark van Schilfgaarde, Gabriel Kotliar

摘要:

量子材料中涌现现象的理论理解是凝聚态物理最大的挑战之一。与贵金属和半导体等简单材料相比,量子材料的宏观性质不能通过单个电子的性质来预测。强关联电子系统是具有重要科学意义的例子之一。电子在部分填充的3d、4f和5f轨道中的定域或巡游行为都不能产生丰富的物理,如莫特绝缘体、高温超导体和优越的热电性,但阻碍了对低位激发谱的定量理解。在这里,我们提出了一个新的第一性原理方法强关联固体。它是基于准粒子自洽GW近似和动力学平均场论的组合的Q4。在这种方法中,唯一的输入是投影到所有局部费曼图正在评估的相关轨道集。为此,我们选择了非常局域化的准原子轨道跨越大的能量窗口,其中包含最强的杂化带,以及上,下哈伯德带。在松原轴上进行自洽。这种方法使莫特绝缘体的顺磁和反铁磁相的第一性原理研究。以典型的电荷转移相关绝缘体La_2CuO_4和NiO为例,给出了与实验符合较好的光谱特性和磁矩。

英文摘要:

The theoretical understanding of emergent phenomena in quantum materials is one of the greatest challenges in condensed matter physics. In contrast to simple materials such as noble metals and semiconductors, macroscopic properties of quantum materials cannot be predicted by the properties of individual electrons. One of the examples of scientific importance is strongly correlated electron system. Neither localized nor itinerant behaviors of electrons in partially filled 3d, 4f, and 5f orbitals give rise to rich physics such as Mott insulators, high-temperature superconductors, and superior thermoelectricity, but hinder quantitative understanding of low-lying excitation spectrum. Here we present a new first-principles approach to strongly correlated solids. It is Q4 based on a combination of the quasiparticle self-consistent GW approximation and the dynamical mean-field theory. The sole input in this method is the projector to the set of correlated orbitals for which all local Feynman graphs are being evaluated. For that purpose, we choose very localized quasiatomic orbitals spanning large energy window, which contains most strongly hybridized bands, as well as upper and lower Hubbard bands. The self-consistency is carried out on the Matsubara axis. This method enables the first-principles study of Mott insulators in both their paramagnetic and antiferromagnetic phases. We illustrate the method on the archetypical charge transfer correlated insulators La2CuO4 and NiO, and obtain spectral properties and magnetic moments in good agreement with experiments.

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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