Spin and charge dynamics of stripes in doped Mott insulators
Abstract
We study spin and charge dynamics of stripes in doped Mott insulators by considering a two-dimensional Hubbard model with N fermion flavors. For N =2 we recover the normal one-band model while for N -> infty a spin density wave mean-field solution. For all band fillings, lattice topologies and N= 4 n the model may be solved by means of Monte Carlo methods without encountering the sign problem. At N=4 and in the vicinity of the Mott insulator, the single particle density of states shows a gap. Within this gap and on rectangular topologies of sizes up to 30 X 12 we find gapless spin collective modes centered around q = (\pi \pm \epsilon_x,\pi \pm \epsilon_y) as well as charge modes centered around q = (\pm 2 \epsilon_x, \pm 2 \epsilon_y), q = (\pm \epsilon_x, \pm \epsilon_y) and q = (0,0). \epsilon_{x,y} depends on the lattice topology and doping.
Cite
@article{arxiv.cond-mat/0206287,
title = {Spin and charge dynamics of stripes in doped Mott insulators},
author = {F. F. Assaad and V. Rousseau and F. Hebert and M. Feldbacher and G. G. Batrouni},
journal= {arXiv preprint arXiv:cond-mat/0206287},
year = {2009}
}
Comments
4 pages, 5 Figues. Submitted to PRL. Corrected typos and added references