Effect of a Staggered Magnetic Field on the S=1 Haldane Chain with Single-ion Anisotropy

TL;DR

This paper investigates how a staggered magnetic field affects the excitation spectrum of an S=1 Haldane chain with single-ion anisotropy, revealing anisotropic gap behavior and spectral weight transfer.

Contribution

It provides a detailed analysis of the spectral gap evolution and spectral weight redistribution in the Haldane chain under a staggered magnetic field, highlighting anisotropic effects.

Findings

Gap along the field increases faster than others

Spectral weight shifts to a two-magnon continuum

Anisotropic excitation spectrum behavior

Abstract

We analyze the gaps in the excitation spectrum of a Haldane chain with single-ion anisotropy in a staggered field. We show that the gap along the direction of the field increases at a faster rate than the others, while its spectral weight decreases, being transferred to a two-magnon continuum.