A single-band Hubbard model with nearest and next-nearest neighbor 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 Muller-Hartmann. For three dimensions and nonpathological band structures, it is proven that such a scenario does not work.
PIERI, P., S. DAUL, D. BAERISWYL, M. DZIERZAWA, P. FAZEKAS (1996). Low density ferromagnetism in the Hubbard model. PHYSICAL REVIEW. B, CONDENSED MATTER, 54(13), 9250-9253 [10.1103/PhysRevB.54.9250].
Low density ferromagnetism in the Hubbard model
PIERI, Pierbiagio;
1996
Abstract
A single-band Hubbard model with nearest and next-nearest neighbor 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 Muller-Hartmann. For three dimensions and nonpathological band structures, it is proven that such a scenario does not work.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
