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.
@article{arxiv.cond-mat/0502393,
title = {Electron Spin Resonance in sine-Gordon spin chains in the perturbative spinon regime},
author = {S. A. Zvyagin and A. K. Kolezhuk and J. Krzystek and R. Feyerherm},
journal= {arXiv preprint arXiv:cond-mat/0502393},
year = {2009}
}