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arXiv · 2201.01057

Quantum spin liquid in the Ising triangular-lattice antiferromagnet neodymium heptatantalate

T. Arh·B. Sana·M. Pregelj·P. Khuntia·Z. Jagličić·M. D. Le·P. Biswas·A. Ozarowski·A. Zorko
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Abstract

Disordered magnetic states known as spin liquids are of paramount importance in both fundamental and applied science. A classical state of this kind was predicted for the Ising antiferromagnetic triangular model more than half a century ago, while additional non-commuting exchange terms were proposed to induce its quantum version -- a quantum spin liquid. These predictions have not been yet confirmed experimentally. Here we report a discovery of such a state in the structurally perfect triangular-lattice antiferromagnet NdTa$_7$O$_{19}$. Its magnetic ground state is characterized by spin-1/2 degrees of freedom with Ising-like interactions and gives rise to low-frequency spin excitations persisting down to the lowest temperatures. Our study demonstrates the key role of strong spin-orbit coupling in stabilizing spin liquids that result from magnetic anisotropy and highlights the large family of rare-earth (RE) heptatantalates RETa$_7$O$_{19}$ as a novel framework for realization of these states, which represent a promising platform for quantum applications.

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T. Arh, B. Sana, M. Pregelj, P. Khuntia, Z. Jagličić, M. D. Le, P. Biswas, A. Ozarowski, A. Zorko. 2022-01-04. Quantum spin liquid in the Ising triangular-lattice antiferromagnet neodymium heptatantalate. https://doi.org/10.1038/s41563-021-01169-y

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