Mean field study of the quasi-one-dimensional antiferromagnetic anisotropic Heisenberg model

摘要

The effect of the chain and the dimer anisotropies on the ground state energy and the energy gap of the spin-1/2 quasi-one-dimensional antiferromagnetic Heisenberg model is investigated using a mean field theory. The dependence of the magnetization and the effective hopping parameters on the anisotropy (alpha)(sup xy)(=J(sup xy)(sub perpendicular)/J(sup xy)(sub parallel)) are presented for several values of the chain anisotropy. However, such a system exhibits a transition from antiferromagnetic ordered to disordered phases for arbitrary chain anisotropy and dimer anisotropy. (author). 22 refs, 11 figs. (Atomindex citation 28:022278)