Exact diagonalization study of optical conductivity in two-dimensional Hubbard model
Abstract
The optical conductivity \sigma(\omega) in the two-dimensional Hubbard model is examined by applying the exact diagonalization technique to small square clusters with periodic boundary conditions up to \sqrt{20} X \sqrt{20} sites. Spectral-weight distributions at half filling and their doping dependence in the 20-site cluster are found to be similar to those in a \sqrt{18} X \sqrt{18} cluster, but different from 4 X 4 results. The results for the 20-site cluster enable us to perform a systematic study of the doping dependence of the spectral-weight transfer from the region of the Mott-gap excitation to lower-energy regions. We discuss the dependence of the Drude weight and the effective carrier number on the electron density at a large on-site Coulomb interaction.
Cite
@article{arxiv.cond-mat/0505404,
title = {Exact diagonalization study of optical conductivity in two-dimensional Hubbard model},
author = {T. Tohyama and Y. Inoue and K. Tsutsui and S. Maekawa},
journal= {arXiv preprint arXiv:cond-mat/0505404},
year = {2007}
}
Comments
5 pages, 5 figures