Orbital differentiation in Hund metals
Orbital differentiation in Hund metals
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DOI：
10.1103/physrevb.100.115159
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发表时间：
2019-09-27
影响因子：
3.7
通讯作者：
von Delft, Jan
中科院分区：
文献类型：
--
作者：
Kugler, Fabian B.;Lee, Seung-Sup B.;von Delft, Jan
轨道分异是多轨道系统的一个共同主题，但对它的完全理解仍然缺失。在这里，我们用一种高度精确的方法考虑了Hund金属中轨道微分的最小模型：我们使用数值重整化群作为实频率杂质解算器，用于三轨道Hubbard模型的动态平均场研究，其中晶体场的能量移动了一个轨道。用动态相关函数对各个相进行了表征，并分析了它们与不同近藤温度的关系。在接近轨道选择性莫特跃迁时，我们发现了一个强烈抑制的自旋相干尺度，并揭示了奇异费米液体和带间双布朗-荷子激发的出现。我们的理论描述了如钌酸盐和铁基超导体等材料的t（2g）带中的各种极化驱动现象，我们的方法进步为强相关材料的实频率分析铺平了道路。
Orbital differentiation is a common theme in multiorbital systems, yet a complete understanding of it is still missing. Here, we consider a minimal model for orbital differentiation in Hund metals with a highly accurate method: We use the numerical renormalization group as a real-frequency impurity solver for a dynamical mean-field study of three-orbital Hubbard models, where a crystal field shifts one orbital in energy. The individual phases are characterized with dynamic correlation functions and their relation to diverse Kondo temperatures. Upon approaching the orbital-selective Mott transition, we find a strongly suppressed spin coherence scale and uncover the emergence of a singular Fermi liquid and interband doublon-holon excitations. Our theory describes the diverse polarization-driven phenomena in the t(2g) bands of materials such as ruthenates and iron-based superconductors, and our methodological advances pave the way toward real-frequency analyses of strongly correlated materials.