Correlated electron systems on the Apollonian network

• Autor(a) principal: Souza, André Maurício Conceição de
• Data de Publicação: 2007
• Outros Autores: Herrmann, Hans Jürgen
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFS
• DOI: 10.1103/PhysRevB.75.054412
• Texto Completo: https://ri.ufs.br/handle/riufs/472
• topic: Apollonian network; Sistemas de elétrons fortemente correlacionados

Strongly correlated electrons on an Apollonian network are studied using the Hubbard model. Ground-state and thermodynamic properties, including specific heat, magnetic susceptibility, spin-spin correlation function, double occupancy, and one-electron transfer, are evaluated applying direct diagonalization and quantum Monte Carlo techniques. In the strong-coupling limit, the quantum anisotropic spin-1∕2 Heisenberg model is used and the phase diagram is discussed using the renormalization group method. The results support an antiferromagnetic order with a metal-insulator transition for U∕t=11.1 at temperature T=0 and a tendency toward a nonordered phase in the half-filled Hubbard model for any U∕t. We also indicate that the spectral dimension must control the magnetic behavior on the Apollonian network.