A. Fledderjohann et al., THE 1D SPIN-1 2 AF-HEISENBERG MODEL IN A STAGGERED FIELD/, The European Physical Journal. B: Condensed Matter Physics, 5(3), 1998, pp. 487-494
We investigate the scaling properties of the excitation energies and t
ransition amplitudes of the one-dimensional spin-1/2 antiferromagnetic
Heisenberg model exposed to an external perturbation. Two types of pe
rturbations are discussed in detail: a staggered field and a dimerized
field.