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.
@article{arxiv.1806.04081,
title = {Quantum Spin Fragmentation in Kagome Ice Ho3Mg2Sb3O14},
author = {Zhiling Dun and Xiaojian Bai and Joseph A. M. Paddison and Nicholas P. Butch and Clarina D. Cruz and Matthew B. Stone and Tao Hong and Martin Mourigal and Haidong Zhou},
journal= {arXiv preprint arXiv:1806.04081},
year = {2021}
}
Comments
15 pages, 5 figures in the main text, 4 figures in the Appendix