We present a mixed spin-(1/2, 5/2) chain composed of a charge-transfer salt (4-Br-o-MePy-V)FeCl4. We observe the entire magnetization curve up to saturation, which exhibits a clear Lieb-Mattis magnetization plateau and subsequent quantum phase transition towards the gapless Luttinger-liquid phase. The observed magnetic behavior is quantitatively explained by a mixed spin-(1/2, 5/2) chain model. The present results demonstrate a quantum many-body effect based on quantum topology and provide a new stage in the search for topological properties in condensed matter physics.
@article{arxiv.2004.10416,
title = {Experimental realization of Lieb-Mattis plateau in a quantum spin chain},
author = {H. Yamaguchi and T. Okita and Y. Iwasaki and Y. Kono and N. Uemoto and Y. Hosokoshi and T. Kida and T. Kawakami and A. Matsuo and M. Hagiwara},
journal= {arXiv preprint arXiv:2004.10416},
year = {2020}
}