Propriedades estáticas e dinâmicas de sistemas fortemente correlacionados

• Autor(a) principal: Ramos, Flávia Braga
• Data de Publicação: 2017
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFU
• Texto Completo: https://repositorio.ufu.br/handle/123456789/18296; http://dx.doi.org/10.14393/ufu.te.2017.60
• topic: Física; Mecânica quântica; Schrodinger, Equação de; Sistemas abertos (Física); Sistemas fortemente correlacionados; DMRG; Escadas quânticas; Entropia de emaranhamento; Correlações dinâmicas; Strongly correlated systems; DMRG; Quantum ladders; Entanglement entropy; Dynamical correlations; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA

In this work, we investigated static and dynamical properties of quasi-one-dimensional strongly correlated systems. The main technique used in the study of such systems was the density matrix renormalization group. In this context, one of the systems that we considered were the spin-s N-leg Heisenberg ladders. For these ladders, we investigated static properties, such as the energy per site in the thermodynamic limit and the spin gap. In particular, we checked the validity of the Haldane-Sénéchal-Sierra's conjecture for the spin gap behavior of the Heisenberg ladders. Also for systems with ladders geometry, another problem that we analyzed was the entanglement entropy of quantum critical ladders. In this case, we proposed a conjecture for the scaling behavior of this entropy. In order to check our conjecture, we consider free fermions, Heisenberg ladders and quantum Ising ladders. Finally, we investigated the behavior of the dynamical correlations in one-dimensional strongly correlated systems. For this case, we presented a detailed study of the asymptotic behavior of the dynamical spin autocorrelations at the bulk and the boundary of such systems.