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arXiv · 2303.08324

Stability of the novel interorbital-hopping mechanism for ferromagnetism in multi-orbital Hubbard models

Ling-Fang Lin·Yang Zhang·Gonzalo Alvarez·Michael A. McGuire·Andrew F. May·Adriana Moreo·Elbio Dagotto
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Abstract

Recently, it was argued that a ferromagnetic (FM) insulating phase can be induced by a novel {\it interorbital} hopping mechanism. Here, we study the stability range of this novel FM phase under modifications in the crystal fields and electronic correlation strength, constructing a theoretical phase diagram. A plethora of states is unveiled, including the FM Mott insulator (MI), a FM orbital-selective Mott phase (OSMP), several anferromagnetic (AFM) MI phases, an AFM metallic state, and a FM metal as well. Our most interesting result is that the FM regime, either in MI or OSMP forms, is shown to be stable in {\it large} portions of the phase diagram, at both intermediate and strong electronic correlations, respectively. Our results demonstrate via a detailed example that the recently proposed novel mechanism to stabilize FM insulators is not fragile but instead robust, and may enlarge substantially the relatively small family of known FM insulators.

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Ling-Fang Lin, Yang Zhang, Gonzalo Alvarez, Michael A. McGuire, Andrew F. May, Adriana Moreo, Elbio Dagotto. 2023-03-15. Stability of the novel interorbital-hopping mechanism for ferromagnetism in multi-orbital Hubbard models. https://doi.org/10.1038/s42005-023-01314-w

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