Heavy Quasi-Particle in the Two-Orbital Hubbard Model
Abstract
The two-orbital Hubbard model with the Hund coupling is investigated in a metallic phase close to the Mott insulator. We calculate the one-particle spectral function and the optical conductivity within dynamical mean field theory, for which the effective impurity problem is solved by using the non-crossing approximation. For a metallic system close to quarter filling, a heavy quasi-particle band is formed by the Hubbard interaction, the effective mass of which is not so sensitive to the orbital splitting and the Hund coupling. In contrast, a heavy quasi-particle band near half filling disappears in the presence of the orbital splitting, but is induced again by the introduction of the Hund coupling, resulting in a different type of heavy quasi-particles.
Cite
@article{arxiv.cond-mat/0106189,
title = {Heavy Quasi-Particle in the Two-Orbital Hubbard Model},
author = {Yoshiki Imai and Norio Kawakami},
journal= {arXiv preprint arXiv:cond-mat/0106189},
year = {2009}
}
Comments
6page, 7eps figures, to appear in J. Phys. Soc. Jpn