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arXiv · 2507.11391

Magnetic ground state and persistent spin fluctuations in triangular-lattice antiferromagnet NdZnAl$_{11}$O$_{19}$

Yantao Cao·Huanpeng Bu·Toni Shiroka·Helen C. Walker·Zhendong Fu·Zhaoming Tian·Jinkui Zhao·Hanjie Guo
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Abstract

Rare-earth triangular-lattice magnets serve as an excellent platform for investigating exotic quantum magnetic phenomena. Recently, the hexaaluminate \cmao\ has been proposed to host a $U(1)$ Dirac quantum spin liquid state with dominant Ising anisotropy. Here, we report a systematic study of its analogue, \nzao, employing ac susceptibility, inelastic neutron scattering, and muon spin relaxation measurements. Inelastic neutron scattering measurements establish a well-defined $J_\mathrm{eff}$ = 1/2 ground state with moderate Ising anisotropy ($g_c$ = 4.54, $g_\mathrm{ab}$ = 1.42). Muon spin relaxation measurements reveal persistent fluctuations emerging below $\sim$15\,K, and extending down to at least 0.28 K. AC susceptibility data further indicate an absence of magnetic ordering or spin freezing down to 50\,mK, despite an overall antiferromagnetic interaction with the Curie-Weiss temprature of $-0.42$\,K. These results suggest that \nzao\ is a good candidate material for realizing a quantum spin liquid state.

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Yantao Cao, Huanpeng Bu, Toni Shiroka, Helen C. Walker, Zhendong Fu, Zhaoming Tian, Jinkui Zhao, Hanjie Guo. 2025-07-15. Magnetic ground state and persistent spin fluctuations in triangular-lattice antiferromagnet NdZnAl$_{11}$O$_{19}$. https://arxiv.org/abs/2507.11391

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