Response of finite spin-S Heisenberg chains to local perturbations
arXiv:cond-mat/9809038 · doi:10.1103/PhysRevB.59.3606
Abstract
We consider the properties of finite isotropic antiferromagnetic Heisenberg chains with S=1/2, 1, 3/2 spins when a weak magnetic field is applied on a few sites, using White's density matrix renormalization group (DMRG) method. For the S=1 chain there exists only one length scale in the system which determines the behavior of the one- and two-point correlation functions both around the local perturbation and near the free boundary. For the critical, half-odd-integer spin cases the exponent of the spin-spin correlation function was found to be , and the exponent of the decay of the site magnetization around the perturbed site is . Close to a free boundary, however, the behavior is completely different for S=1/2 and .
13 pages, 7 figures