Dynamics of doublon-holon pairs in Hubbard two-leg ladders
Abstract
The dynamics of holon-doublon pairs is studied in Hubbard two-leg ladders using the time-dependent Density Matrix Renormalization Group method. We find that the geometry of the two-leg ladder, that is qualitatively different from a one-dimensional chain due to the presence of a spin-gap, strongly affects the propagation of a doublon-holon pair. Two distinct regimes are identified. For weak inter-leg coupling, the results are qualitatively similar to the case of the propagation previously reported in Hubbard chains, with only a renormalization of parameters. More interesting is the case of strong inter-leg coupling where substantial differences arise, particularly regarding the double occupancy and properties of the excitations such as the doublon speed. Our results suggest a connection between the presence of a spin gap and qualitative changes in the doublon speed, indicating a weak coupling between the doublon to magnetic excitations.
Keywords
Cite
@article{arxiv.1208.2225,
title = {Dynamics of doublon-holon pairs in Hubbard two-leg ladders},
author = {Luis G. G. V. Dias da Silva and Gonzalo Alvarez and Elbio Dagotto},
journal= {arXiv preprint arXiv:1208.2225},
year = {2012}
}
Comments
8 pages, 9 figures. Published version