2 papers
cond-mat.stat-mech2004
Effects of anisotropy on a quantum Heisenberg spin glass in a three-dimensional hierarchical lattice
J. Ricardo de Sousa, Beatriz Boechat, Claudette Cordeiro +1
We study the anisotropic Heisenberg spin-glass model in a three-dimensional hierarchical lattice (designed to approximate the cubic lattice), within a real-space renormalization-gr…
cond-mat1997
The Two - Dimensional Attractive Hubbard Model: Highly Non-Linear Superconductivity With Sum Rules
J. J. Rodriguez - Nunez, C. E. Cordeiro, A. Delfino
We use the moment approach of Nolting (exact sum rules) (Z. Physik 255, 25 (1972)) for the attractive Hubbard model in the superconducting phase. Our diagonal and off - diagonal sp…