Electron Spin Resonance in sine-Gordon spin chains in the perturbative spinon regime

TL;DR

This study uses low-temperature ESR measurements on a spin-1/2 antiferromagnetic chain compound to validate a recent theoretical model based on bosonization, achieving excellent agreement between theory and experiment.

Contribution

It provides the first experimental validation of Oshikawa and Affleck's theoretical predictions for ESR parameters in the perturbative spinon regime.

Findings

Quantitative agreement between ESR measurements and theory

Validation of bosonization-based theoretical models

Insights into Dzyaloshinskii-Moriya interactions in spin chains

Abstract

We report the low-temperature multi-frequency ESR studies of copper pyrimidine dinitrate, a spin-1/2 antiferromagnetic chain with alternating $g$-tensor and the Dzyaloshinskii-Moriya interaction, allowing us to test a new theoretical concept proposed recently by Oshikawa and Affleck [Phys. Rev. Lett. 82, 5136 (1999)]. Their theory, based on bosonization and the self-energy formalism, can be applied for precise calculation of ESR parameters of $S=1/2$ antiferromagnetic chains in the perturbative spinon regime. Excellent quantitative agreement between the theoretical predictions and experiment is obtained.