Effects of two-site composite excitations in the Hubbard model
Strongly Correlated Electrons
2007-05-23 v1
Abstract
The electronic states of the Hubbard model are investigated by use of the Composite Operator Method. In addition to the Hubbard operators, two other operators related with two-site composite excitations are included in the basis. Within the present formulation, higher-order composite excitations are reduced to the chosen operatorial basis by means of a procedure preserving the particle-hole symmetry. The positive comparison with numerical simulations for the double occupancy indicates that such approximation improves over the two-pole approximation.
Keywords
Cite
@article{arxiv.cond-mat/0401083,
title = {Effects of two-site composite excitations in the Hubbard model},
author = {A. Avella and F. Mancini and S. Odashima},
journal= {arXiv preprint arXiv:cond-mat/0401083},
year = {2007}
}
Comments
2 pages, 1 figure