Dynamical properties of S=1 bond-alternating Heisenberg chains in transverse magnetic fields

TL;DR

This paper investigates the dynamical properties of S=1 bond-alternating Heisenberg chains under transverse magnetic fields, revealing characteristic field-dependent behaviors consistent with experimental neutron-scattering data.

Contribution

It introduces a continued fraction method based on the Lanczos algorithm to calculate dynamical structure factors in these quantum spin chains, providing new insights into their field-dependent properties.

Findings

Dynamical structure factors vary with magnetic field in Haldane-gap and dimer phases.

Numerical results qualitatively match recent neutron-scattering experiments.

Characteristic field dependence observed in the dynamical properties.

Abstract

We calculate dynamical structure factors of the S=1 bond-alternating Heisenberg chain with a single-ion anisotropy in transverse magnetic fields, using a continued fraction method based on the Lanczos algorithm. In the Haldane-gap phase and the dimer phase, dynamical structure factors show characteristic field dependence. Possible interpretations are discussed. The numerical results are in qualitative agreement with recent results for inelastic neutron-scattering experiments on the S=1 bond-alternating Heisenberg-chain compound $\rm{Ni(C_{9}D_{24}N_{4})(NO_{2})ClO_{4}}$ and the S=1 Haldane-gap compound $\rm{Ni(C_{5}D_{14}N_{2})_{2}N_{3}(PF_{6})}$ in transverse magnetic fields.