We investigate a spin-21 antiferromagnet, CuBr2, which has quasi-one-dimensional structural motifs. The system has previously been observed to exhibit unusual Raman modes possibly due to a locally deformed crystal structure driven by the low-dimensional magnetism. Using hard X-ray scattering and neutron total scattering, here we aim to verify a specific form of tetramerized lattice deformation proposed in the previous study. Apart from diffuse scattering signals which we can reproduce by performing a thorough modeling of the lattice's thermal vibrations, we do not observe evidence for a tetramerized lattice structure within our detection sensitivity. As a result, it is more likely that the unusual Raman modes in CuBr2 arise from classical magnon-phonon hybridization, rather than from quantum spin-singlet-driven lattice deformation.
@article{arxiv.2312.09055,
title = {Exploration of magnetoelastic deformations in spin-chain compound CuBr$_2$},
author = {Biaoyan Hu and Yingying Peng and Xiaoqiang Liu and Qizhi Li and Qiangqiang Gu and Matthew J. Krogstad and Raymond Osborn and Takashi Honda and Ji Feng and Yuan Li},
journal= {arXiv preprint arXiv:2312.09055},
year = {2024}
}