Helicity Modulus and Effective Hopping in the Two-Dimensional Hubbard Model Using Slave-Boson Methods
Abstract
The slave-boson mean-field method is used to study the two-dimensional Hubbard model. A magnetic phase diagram allowing for paramagnetism, weak- and strong ferromagnetism and antiferromagnetism, including all continuous and first-order transitions, is constructed and compared to the corresponding phase diagram using the Hartree-Fock approximation (HFA). Magnetically ordered regions are reduced by a factor of about 3 along both the and density axes compared to the HFA. Using the spin-rotation invariant formulation of the slave-boson method the helicity modulus is computed and for half-filling is found to practically coincide with that found using variational Monte Carlo calculations using the Gutzwiller wave function. Off half-filling the results can be used to compare with Quantum Monte Carlo calculations of the effective hopping parameter. Contrary to the case of half-filling, the slave-boson approach is seen to greatly improve the results of the HFA when off half-filling. (Submitted to: Journal of Physics: Condensed Matter)
Keywords
Cite
@article{arxiv.cond-mat/9406093,
title = {Helicity Modulus and Effective Hopping in the Two-Dimensional Hubbard Model Using Slave-Boson Methods},
author = {P. J. H. Denteneer and M. Blaauboer},
journal= {arXiv preprint arXiv:cond-mat/9406093},
year = {2009}
}
Comments
27 pages, LaTeX2e, 7 figures available upon request, INLO-PUB-10/94