arXiv:cond-mat/9909388 · Physical review. B, Condensed matter
Finite-size spectrum, magnon interactions, and magnetization of S=1 Heisenberg spin chains
Jizhong Lou, Shaojin Qin, Tai Kai Ng, Zhao-Bin Su, Ian K. Affleck
Abstract
We report on density-matrix renormalization-group and analytical work on $S=1$ antiferromagnetic Heisenberg spin chains. We study the finite-size behavior within the framework of the nonlinear $\ensuremath{\sigma}$ model. We study the effect of magnon-magnon interactions on the finite-size spectrum and on the magnetization curve close to the critical magnetic field, determine the magnon scattering length, and compare it to the prediction from the nonlinear $\ensuremath{\sigma}$ model.