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Ferromagnetism in a Realistic Two-Band Model: A Slave-Boson Study

Raymond Fresard·Mathieu Lamboley
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Abstract

Using a slave boson representation of multi-band Hubbard models, we investigate a two-band model relevant to layered perovskites in the vicinity of half-filling. Beside the strong influence of the Hund's rule coupling, we obtain that the phase diagram separates into two regions: a weak to moderate coupling region where the effective mass is weakly renormalized, and a strong coupling regime where it is strongly renormalized. The transition between these two regimes is very sharp. It takes place in a (vanishingly) small domain. A ferromagnetic instability in only found in the strongly correlated regime, and is triggered by the Hund's rule coupling. The results are compared to La-doped layered ruthenates.

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Raymond Fresard, Mathieu Lamboley. 2001-09-28. Ferromagnetism in a Realistic Two-Band Model: A Slave-Boson Study. https://arxiv.org/abs/cond-mat/0109543

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