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arXiv · 1106.0815

Janus-faced influence of the Hund's rule coupling in strongly correlated materials

Luca de' Medici·Jernej Mravlje·Antoine Georges
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Abstract

We show that in multi-band metals the correlations are strongly affected by the Hund's rule coupling, which depending on the filling promotes metallic, insulating or bad-metallic behavior. The quasiparticle coherence and the proximity to a Mott insulator are influenced distinctly and, away from single- and half-filling, in opposite ways. A strongly correlated bad-metal far from a Mott phase is found there. We propose a concise classification of 3d and 4d transition-metal oxides within which the ubiquitous occurrence of strong correlations in Ru- and Cr-based oxides, as well as the recently measured high Néel temperatures in Tc-based perovskites are naturally explained.

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Luca de' Medici, Jernej Mravlje, Antoine Georges. 2011-06-04. Janus-faced influence of the Hund's rule coupling in strongly correlated materials. https://doi.org/10.1103/physrevlett.107.256401

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