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arXiv · 1208.2225

Dynamics of doublon-holon pairs in Hubbard two-leg ladders

Luis G. G. V. Dias da Silva·Gonzalo Alvarez·Elbio Dagotto
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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.

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Luis G. G. V. Dias da Silva, Gonzalo Alvarez, Elbio Dagotto. 2012-11-23. Dynamics of doublon-holon pairs in Hubbard two-leg ladders. https://doi.org/10.1103/physrevb.86.195103

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