The vacancy effect in quantum spin liquid (QSL) has been extensively studied. A finite density of random vacancies in the Kitaev model can lead to a pileup of low-energy density of states (DOS), which is generally experimentally determined by a scaling behavior of thermodynamic or magnetization quantities. Here, we report detailed muon spin relaxation (μSR) results of H3LiIr2O6, a Kitaev QSL candidate with vacancies. The absence of magnetic order is confirmed down to 80 mK, and the spin fluctuations are found to be persistent at low temperatures. Intriguingly, the time-field scaling law of longitudinal-field (LF)-μSR polarization is observed down to 0.1 K. This indicates a dynamical scaling, whose critical exponent 0.46 is excellently consistent with the scaling behavior of specific heat and magnetization data. All the observations point to the finite DOS with the form N(E)∼E−0.5 , which is expected for the Kitaev QSL in the presence of vacancies. Our {\mu}SR study provides a dynamical fingerprint of the power-law low-energy DOS, and introduces a crucial new insight into the vacancy effect in QSL.
@article{arxiv.2201.12978,
title = {Muon Spin Relaxation Study of Spin Dynamics on a Kitaev honeycomb material H$_3$LiIr$_2$O$_6$},
author = {Yan-Xing Yang and Cheng-Yu Jiang and Liang-Long Huang and Zi-Hao Zhu and Chang-Sheng Chen and Qiong Wu and Zhao-Feng Ding and Cheng Tan and Pabi K. Biswas and Adrian D. Hillier and You-Guo Shi and Cai Liu and Le Wang and Fei Ye and Jia-Wei Mei and Lei Shu},
journal= {arXiv preprint arXiv:2201.12978},
year = {2024}
}