Nonlocal correlations induced by Hund's coupling: A cluster DMFT study

Article

关键词: MEAN-FIELD THEORY;    INFINITE DIMENSIONS;    ORBITAL DEGENERACY;    QUANTUM;    FERROMAGNETISM;    SYSTEMS;   

DOI  :  10.1103/PhysRevB.91.235107

来源: SCIE

【 摘 要 】

We study spatial correlation effects in multiorbital systems, especially in a paramagnetic metallic state subject to Hund's coupling. We apply a cluster extension of the dynamical mean-field theory (DMFT) to the three-orbital Hubbard model away from half filling, where previous single-site DMFT studies revealed that local correlation effects caused by Hund's coupling bring about unusual strongly correlated metallic behaviors. We find that Hund's coupling significantly affects the nonlocal correlations too; it strongly modulates the electron distribution in the momentum space so as to make a momentum region almost half filled and hence strongly correlated. It leads to an anomalous electronic state distinct both from the Fermi liquid and the Mott insulator. We identify the mechanism of the anomalous state with the intersite ferromagnetic correlations induced by Hund's coupling.

【 授权许可】

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