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arXiv · 1806.04081

Quantum Spin Fragmentation in Kagome Ice Ho3Mg2Sb3O14

Zhiling Dun·Xiaojian Bai·Joseph A. M. Paddison·Nicholas P. Butch·Clarina D. Cruz·Matthew B. Stone·Tao Hong·Martin Mourigal·Haidong Zhou
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Abstract

A promising route to realize entangled magnetic states combines geometrical frustration with quantum-tunneling effects. Spin-ice materials are canonical examples of frustration, and Ising spins in a transverse magnetic field are the simplest many-body model of quantum tunneling. Here, we show that the tripod kagome lattice material Ho3Mg2Sb3O14 unites an ice-like magnetic degeneracy with quantum-tunneling terms generated by an intrinsic splitting of the Ho3+ ground-state doublet, realizing a frustrated transverse Ising model. Using neutron scattering and thermodynamic experiments, we observe a symmetry-breaking transition at T*~0.32 K to a remarkable quantum state with three peculiarities: a continuous magnetic excitation spectrum down to T~0.12K; a macroscopic degeneracy of ice-like states; and a fragmentation of the spin into periodic and aperiodic components strongly affected by quantum fluctuations. Our results establish that Ho3Mg2Sb3O14 realizes a spin-fragmented state on the kagome lattice, with intrinsic quantum dynamics generated by a homogeneous transverse field.

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Zhiling Dun, Xiaojian Bai, Joseph A. M. Paddison, Nicholas P. Butch, Clarina D. Cruz, Matthew B. Stone, Tao Hong, Martin Mourigal, Haidong Zhou. 2018-06-11. Quantum Spin Fragmentation in Kagome Ice Ho3Mg2Sb3O14. https://arxiv.org/abs/1806.04081

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