Eur. Phys. J. B 10, 409-414 (1999)
https://doi.org/10.1007/s100510050870

A generalized spin ladder in a magnetic field

Institut für Theoretische Physik, Universität Hannover, 30167 Hannover, Germany

Corresponding author: ^a frahm@itp.uni-hannover.de

Received: 17 November 1998
Revised: 22 January 1999
Published online: 15 August 1999

Abstract

We study the phase diagram of coupled spin-1/2 chains with bilinear and (chiral) three-spin exchange interactions in a magnetic field. The model is soluble on a one-parametric line in the space of coupling constants connecting the limiting cases of a single and two decoupled Heisenberg chains with nearest neighbour exchange only. We give a complete classification of the low-energy properties of the integrable system and introduce a numerical method which allows to study the possible phases of spin ladder systems away from the soluble line in a magnetic field.