arXiv:1111.0361
Phase diagrams and critical behavior of the quantum spin-1/2 XXZ model on diamond-type hierarchical lattices
Xiu-Xing Zhang, Xiang-Mu Kong, Zhong-Yang Gao, Xiao-Song Chen
Abstract
In this paper, the phase diagrams and the critical behavior of the spin-1/2 anisotropic XXZ ferromagnetic model (the anisotropic parameter Δ\in(-\infty,1]) on two kinds of diamond-type hierarchical (DH) lattices with fractal dimensions d_{f}=2.58 and 3, respectively, are studied via the real-space renormalization group method. It is found that in the isotropic Heisenberg limit (Δ=0), there exist finite temperature phase transitions for the two kinds of DH lattices above. The systems are also investigated in the range of -\infty