We report the discovery of a dynamic magnetic ground state in the ${\mathrm{Yb}}^{3+}$ dimer-based compound ${\mathrm{Yb}}_2{\mathrm{Te}}_5{\mathrm{O}}_{13}$ through various characterization techniques down to sub-Kelvin temperatures. Magnetization measurements reveal the absence of long-range magnetic ordering down to 0.4 K and the onset of magnetic correlations below 1 K. Heat capacity data, measured down to 0.37 K, indicate a small finite energy gap in zero field, $\mathrm{\Delta }\left(0\right)\sim$ 0.55 K, and validate the presence of magnetic correlations with a Kramers doublet ground state ($J_{\text{eff}}$ = 1/2). Further insight is provided by zero-field muon spin relaxation ($\mu \mathrm{SR}$) measurements, which show a gradual slowdown of ${\mathrm{Yb}}^{3+}$ spin fluctuations below 30 K, indicating a dynamic state down to 44 mK. The temperature dependence of the relaxation rate, $\lambda$, confirms the presence of the Orbach process, which is mediated through various crystal electric field levels, complementing the $J_{\text{eff}}$ = 1/2 ground state. Furthermore, longitudinal field $\mu \mathrm{SR}$ measurements performed at 70 mK demonstrate that the ${\mathrm{Yb}}^{3+}$ spins remain dynamic even under an external field of 3200 Oe, with fluctuations becoming stronger with increasing magnetic field. Theoretical investigations further support the dynamic state, revealing competition between intra- and interdimer exchange interactions as the underlying cause. By integrating macroscopic and microscopic measurements with theoretical insights, we propose ${\mathrm{Yb}}_2{\mathrm{Te}}_5{\mathrm{O}}_{13}$ as a quantum spin liquid candidate, opening avenues for research in quantum magnetism.

Close

PrevNext

View figure in article

• Quantum spin liquid
• Spin dynamics
• Density functional theory
• Monte Carlo methods
• Muon spin relaxation & rotation