Journal of Physics A Mathematical and General
Calculation of finite-size corrections for the antiferromagnetic Heisenberg chain
B -D Dorfel, St Meißner
Abstract
The finite-size corrections for the anisotropic Heisenberg model in the gap region are calculated using an exact integral representation based on the Bethe ansatz equations (BAE). The energy corrections are determined by saddle-point approximations for states without complex roots. The case of symmetric states is discussed in greater detail.