arXiv:cond-mat/0201014 · Progress of Theoretical Physics Supplement
Anisotropies of the Hamiltonian and the Wave Function: Inversion Phenomena in Quantum Spin Chains
Kiyomi Okamoto
Abstract
We investigate the inversion phenomenon between the XXZ anisotropies of the Hamiltonian and the wave function in quantum spin chains, focusing mainly on the S = 1/2 trimerized XXZ model with the next-nearest-neighbor interactions. We have obtained the ground-state phase diagram by use of the degenerate perturbation theory and the level spectroscopy analysis of the numerical data calculated by the Lanczös method. In some parameter regions, the spin-fluid phase is realized for the Ising-like anisotropy, and the Néel phase for the XY-like anisotropy, against the ordinary situation.