The influence of long-range hopping on ferromagnetism in the Hubbard model

Abstract

The phase diagram of the Hubbard model in an external magnetic field is examined by extrapolation of small-cluster exact-diagonalization calculations. Using a general expression for the hopping matrix elements ($t_{ij}\sim q^{|i-j|}$) the influence of long-range hopping (band asymmetry) on ferromagnetism in this model is studied. It is found that the long-range hopping (nonzero $q$) stabilizes ferromagnetism in an external magnetic field for $n>1$. In the opposite limit $n\le 1$ the fully polarized ferromagnetic state is generally suppressed with increasing $q$. The critical value of magnetic field $h$ below which the ferromagnetic state becomes unstable is calculated numerically.

8 pages, 3 Postscript figures, LateX

References in corpus (4)

• Ferromagnetism in the Hubbard Model-- Examples from Models with Degenerate Single-Electron Ground States
• Ferromagnetism in Hubbard Models: Low Density Route
• Low density ferromagnetism in the Hubbard model
• The Hubbard model on a complete graph: Exact Analytical results

Cited by in corpus (1)

• Ferromagnetism in the Hubbard model with a generalized type of hopping