We report a comprehensive single-crystal neutron diffraction investigation of the Kitaev quantum magnet α-RuCl3 under hydrostatic pressure. Utilizing a He-gas pressure cell, we successfully applied an ideal hydrostatic pressure in situ at low temperatures, which allows to effectively eliminate any possible influences from the structural transition occurring between 200 K and 50 K under ambient conditions. Our experiments reveal a gradual suppression of the ziagzag antiferromagnetic order as hydrostatic pressure increases. Furthermore, a reversible pressure-induced structural transition occurs at a critical pressure of Pd = 0.15 GPa at 30 K, as evidenced by the absence of magnetic order and non-uniform changes in lattice constants. The decrease in magnetic transition temperature is discussed in relation to a pressure-induced change in the trigonal distortion of the Ru-Cl octahedra in this compound. Our findings emphasize the significance of the trigonal distortion in Kitaev materials, and provide a new perspective on the role of hydrostatic pressures in the realization of the Kitaev quantum spin liquid state in α-RuCl3.
@article{arxiv.2304.00632,
title = {Hydrostatic pressure effects in the Kitaev quantum magnet $\alpha$-RuCl$_3$: A single-crystal neutron diffraction study},
author = {Xiao Wang and Fengfeng Zhu and Navid Qureshi and Ketty Beauvois and Junda Song and Thomas Mueller and Thomas Brückel and Yixi Su},
journal= {arXiv preprint arXiv:2304.00632},
year = {2023}
}