Qin, Y.; Shen, Y.; Liu, C.; Wo, H.; Gao, Y.; Feng, Y.; Zhang, X.; Ding, G.; Gu, Y.; Wang, Q.; Shen, S.; Walker, H.C.; Bewley, R.; Xu, J.; Boehm, M.; Steffens, P.; Ohira-Kawamura, S.; Murai, N.; Schneidewind, A.; Tong, X.; Chen, G.; Zhao, J.: Field-tuned quantum effects in a triangular-lattice Ising magnet. Science Bulletin 67 (2022), p. 38-44
10.1016/j.scib.2021.08.012
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Abstract:
We report thermodynamic and neutron scattering measurements of the triangular-lattice quantum Ising magnet TmMgGaO4 in longitudinal magnetic fields. Our experiments reveal a quasi-plateau state induced by quantum fluctuations. This state exhibits an unconventional non-monotonic field and temperature dependence of the magnetic order and excitation gap. In the high field regime where the quantum fluc- tuations are largely suppressed, we observed a disordered state with coherent magnon-like excitations despite the suppression of the spin excitation intensity. Through detailed semi-classical calculations, we are able to understand these behaviors quantitatively from the subtle competition between quantum fluctuations and frustrated Ising interactions.