Existence of the Spin-Wave Gap in a Deformed Flat-Band Hubbard Model
Strongly Correlated Electrons
2007-05-23 v1 Mathematical Physics
math.MP
Abstract
We consider a deformed flat-band Hubbard model under a periodic boundary condition in arbitrary dimensions. We show that the ground state is only all-spin-up or -down state. We obtain upper and lower bounds of the one-magnon spin-wave energy with an arbitrary momentum. This dispersion relation is the same as that in the XXZ model in the certain parameter region. Therefore the spin wave has a finite energy gap. These results suggests the our model and the XXZ model.
Keywords
Cite
@article{arxiv.cond-mat/0411362,
title = {Existence of the Spin-Wave Gap in a Deformed Flat-Band Hubbard Model},
author = {Makoto Homma},
journal= {arXiv preprint arXiv:cond-mat/0411362},
year = {2007}
}
Comments
30 pages, 1 figure