Formation of heavy quasiparticle state in two-band Hubbard model
Abstract
A realization of heavy fermion state is investigated on the basis of two-band Hubbard model. By means of the slave-boson mean-field approximation, it is shown that for the intermediate electron density, n_e=1.5, the inter-band Coulomb repulsion U strongly emphasizes initially small difference between bands, and easily stabilizes integral valence in the lower band. As a result, a strong renormalization takes place in the lower band and the mixing strength between two bands. It gives rise to a sharp peak at the Fermi level in the quasiparticle density of states, as that obtained in the periodic Anderson model. In contrast to a simple insight that the Hund's-rule coupling J reduces the characteristic energy, it turns out to be almost irrelevant to the renormalization for J<U. The required conditions are suitable for LiV_2O_4, the first observed heavy fermion compound in transition metal oxide.
Keywords
Cite
@article{arxiv.cond-mat/9912208,
title = {Formation of heavy quasiparticle state in two-band Hubbard model},
author = {H. Kusunose and S. Yotsuhashi and K. Miyake},
journal= {arXiv preprint arXiv:cond-mat/9912208},
year = {2009}
}
Comments
5 pages, 4 figures, to be published in Phys. Rev. B