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arXiv · 2501.04653

Evidence for spin liquid behavior in the frustrated three-dimensional $S = 1/2$ Heisenberg garnet NaCa$_{2}$Cu$_{2}$(VO$_{4}$)$_{3}$

Y. Alexanian·R. Kumar·H. Zeroual·B. Bernu·L. Mangin-Thro·J. R. Stewart·J. M. Wilkinson·S. Bhattacharya·P. L. Paulose·F. Bert·P. Mendels·B. Fåk·E. Kermarrec
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Abstract

Three-dimensional quantum spin liquids have remained elusive, hindered by reduced quantum fluctuations from larger lattice connectivity inherent to high-dimensional systems. Here, we investigate the remarkable persistence of dynamical short-range magnetic correlations in the nearly body-centered cubic garnet NaCa$_{2}$Cu$_{2}$(VO$_{4}$)$_{3}$ down to $T = 50$ mK, two orders of magnitude below its Curie-Weiss temperature. Using a combination of neutron and muon spectroscopies plus numerical simulations, we demonstrate that a dynamical regime emerges, characterized by a dual response in the inelastic spectrum composed of short-live dispersive excitations and a quasi-elastic component. Strongly frustrated exchange interactions combined with subtle temperature-dependent Jahn-Teller spin-lattice effects are a plausible mechanism to explain the origin of this spin-liquid behavior.

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Y. Alexanian, R. Kumar, H. Zeroual, B. Bernu, L. Mangin-Thro, J. R. Stewart, J. M. Wilkinson, S. Bhattacharya, P. L. Paulose, F. Bert, P. Mendels, B. Fåk, E. Kermarrec. 2025-01-08. Evidence for spin liquid behavior in the frustrated three-dimensional $S = 1/2$ Heisenberg garnet NaCa$_{2}$Cu$_{2}$(VO$_{4}$)$_{3}$. https://doi.org/10.1103/crg9-9txm

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