Eur. Phys. J. B 29, 35-40 (2002)
https://doi.org/10.1140/epjb/e2002-00259-9

The spin-1/2 anisotropic Heisenberg-chain in longitudinal and transversal magnetic fields: a DMRG study

Universität des Saarlandes, Fakultät 7.1, Postfach 15 11 50, 66041 Saarbrücken, Germany

Corresponding author: ^a capraro@lusi.uni-sb.de

Received: 16 April 2002
Revised: 4 July 2002
Published online: 17 September 2002

Abstract

Using the density matrix renormalization group technique, we evaluate the low-energy spectrum (ground state and first excited states) of the anisotropic antiferromagnetic spin-one-half chain under magnetic fields. We study both homogeneous longitudinal and transversal fields as well as the influence of a transversal staggered field on the opening of a spin-gap. We find that only a staggered transversal field opens a substantial gap.