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Correlated electrons systems on the Apollonian network

Andre M. C. Souza·Hans Herrmann
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Abstract

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. The results support several types of magnetic behavior. 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. For ferromagnetic coupling, we always observe the existence of long-range order. For antiferromagnetic coupling, we find a paramagnetic phase for all finite temperatures.

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Andre M. C. Souza, Hans Herrmann. 2006-10-04. Correlated electrons systems on the Apollonian network. https://doi.org/10.1103/physrevb.75.054412

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