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$μ$SR study of the quantum dynamics in the frustrated $S=3/2$ kagome bilayers

David Bono·P. Mendels·G. Collin·N. Blanchard·F. Bert·A. Amato·C. Baines·A. D. Hillier
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Abstract

We present $μ$SR experiments in the $S=3/2$ kagome bilayer compound Ba$_{2}$Sn$_{2}$ZnGa$_{10-7p}$Cr$_{7p}$O$_{22}$ (BSZCGO$(p)$) and compare it to the isostructural SrCr$_{9p}$Ga$_{12-9p}$O$_{19}$ (SCGO$(p)$), including for the latter new results for $p\geq0.89$. Quantum-dynamical low energy magnetic excitations are evidenced in this novel compound. We study the evolution of the muon relaxation rate with $p$, $T$ and field. A phenomenological model for the muon relaxation based on sporadic dynamics due to spin excitations in a singlet sea proposed by Uemura \emph{et al.} [Phys. Rev. Lett. \textbf{73}, 3306 (1994)]. is extended to all fields and $T$-range. Its connexion to the RVB picture is discussed, and we argue that such coherent states might mediate the interactions between "impurities" which induce the spin glass freezing.

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David Bono, P. Mendels, G. Collin, N. Blanchard, F. Bert, A. Amato, C. Baines, A. D. Hillier. 2004-09-13. $μ$SR study of the quantum dynamics in the frustrated $S=3/2$ kagome bilayers. https://doi.org/10.1103/physrevlett.93.187201

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