Excitonic properties in the Kagome lattice system, which is produced by quantum wires on semiconductor surfaces, are investigated by using the exact diagonalization of a tight binding model. It is shown that due to the existence of flat bands the binding energy of exciton becomes remarkably large in the two-dimensional Kagome lattice compared to that in one-dimensional lattice, and the exciton Bohr radius is quite small as large as a lattice constant. We also discuss the magnetic field effects on the exciton binding energy and the stability of exciton against the creation of charged exciton and biexciton.
@article{arxiv.cond-mat/0110360,
title = {Flat-band excitonic states in Kagome lattice on semiconductor surface},
author = {H. Ishii and T. Nakayama and J. Inoue},
journal= {arXiv preprint arXiv:cond-mat/0110360},
year = {2009}
}