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Low density ferromagnetism in the Hubbard model

P. Pieri·S. Daul·D. Baeriswyl·M. Dzierzawa·P. Fazekas
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Abstract

A single-band Hubbard model with nearest and next-nearest neighbour hopping is studied for $d=1$, 2, 3, using both analytical and numerical techniques. In one dimension, saturated ferromagnetism is found above a critical value of $U$ for a band structure with two minima and for small and intermediate densities. This is an extension of a scenario recently proposed by Müller--Hartmann. For three dimensions and non-pathological band structures, it is proven that such a scenario does not work.

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P. Pieri, S. Daul, D. Baeriswyl, M. Dzierzawa, P. Fazekas. 1996-03-26. Low density ferromagnetism in the Hubbard model. https://doi.org/10.1103/physrevb.54.9250

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