Spin-Wave Description of Haldane-gap antiferromagnets

TL;DR

This paper introduces a modified spin-wave theory to accurately describe the magnetic properties of Haldane-gap antiferromagnets, overcoming previous limitations in one-dimensional systems and providing insights into ground-state and finite-temperature behaviors.

Contribution

It presents a novel modified spin-wave approach that maintains sublattice symmetry and effectively models both ground-state correlations and finite-temperature properties of Haldane-gap antiferromagnets.

Findings

Accurately describes ground-state correlations.

Provides insights into finite-temperature properties.

Overcomes divergence issues in one-dimensional systems.

Abstract

Modifying the conventional antiferromagnetic spin-wave theory which is plagued by the difficulty of the zero-field sublattice magnetizations diverging in one dimension, we describe magnetic properties of Haldane-gap antiferromagnets. The modified spin waves, constituting a grand canonical bosonic ensemble so as to recover the sublattice symmetry, not only depict well the ground-state correlations but also give useful information on the finite-temperature properties.