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

Autor(es)

Dias da Silva, Luis G. G. V. ^[1] ; Alvarez, G. ^{[2, 3]} ; Dagotto, E. ^{[4, 5]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis, BR-05315970 Sao Paulo - Brazil

^[2] Oak Ridge Natl Lab, Comp Sci & Math Div, Oak Ridge, TN 37831 - USA

^[3] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 - USA

^[4] Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 - USA

^[5] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 - USA

• Tipo de documento: Artigo Científico
• Fonte: Physical Review B; v. 86, n. 19 NOV 5 2012.
• Citações Web of Science: 6

Resumo

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, which 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 interleg 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 interleg 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 and the magnetic excitations. (AU)

• Processo FAPESP: 10/20804-9 - Estudos computacionais de correlação eletrônica e dinâmica dependente do tempo em nanoestruturas
• Beneficiário: Luis Gregório Godoy de Vasconcellos Dias da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular