Triplet spin resonance of the Haldane compound with interchain coupling

TL;DR

This study investigates triplet spin resonance in the Haldane magnet PbNi2V2O8, revealing temperature-dependent spectra and interactions between triplets, supporting a bosonic field theory model over noninteracting chain models.

Contribution

It provides experimental evidence of triplet resonance features and supports a bosonic field theory description of the magnetic excitations in the Haldane compound.

Findings

Resonance spectrum shows all three spin components.

Resonance field varies with temperature, indicating spectrum renormalization.

Results align with bosonic field theory, contradicting noninteracting chain models.

Abstract

Spin resonance absorption of the triplet excitations is studied experimentally in the Haldane magnet PbNi2V2O8. The spectrum has features of spin S=1 resonance in a crystal field, with all three components, corresponding to transitions between spin sublevels, being observable. The resonance field is temperature dependent, indicating the renormalization of excitation spectrum in interaction between the triplets. Magnetic resonance frequencies and critical fields of the magnetization curve are consistent with a boson version of the macroscopic field theory [Affleck 1992, Farutin & Marchenko 2007], implying the field induced ordering at the critical field, while contradict the previously used approach of noninteracting spin chains.