Haldane-gap chains in a magnetic field

TL;DR

This paper investigates the effects of a magnetic field on quasi-one-dimensional spin-1 Heisenberg chains with anisotropy, analyzing dynamical properties and experimental relevance, especially in neutron scattering studies of Haldane-gap materials.

Contribution

It provides a comprehensive analysis of the dynamical structure factor in various magnetic field regimes, including interchain coupling effects, for Haldane-gap chains.

Findings

Field-dependent width of magnon modes

Qualitative changes in dynamical structure factor

Relevance to neutron scattering experiments

Abstract

We consider quasi one dimensional spin-1 Heisenberg chains with crystal field anisotropy in a uniform magnetic field. We determine the dynamical structure factor in various limits and obtain a fairly complete qualitative picture of how it changes with the applied field. In particular, we discuss how the width of the higher energy single magnon modes depends on the field. We consider the effects of a weak interchain coupling. We discuss the relevance of our results for recent neutron scattering experiments on the quasi-1D Haldane-gap compound NDMAP.