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arXiv · 2011.09376

Field-Tuned Quantum Effects in a Triangular-Lattice Ising Magnet

Yayuan Qin·Yao Shen·Changle Liu·Hongliang Wo·Yonghao Gao·Yu Feng·Xiaowen Zhang·Gaofeng Ding·Yiqing Gu·Qisi Wang·Shoudong Shen·Helen C. Walker·Robert Bewley·Jianhui Xu·Martin Boehm·Paul Steffens·Seiko Ohira-Kawamura·Naoki Murai·Astrid Schneidewind·Xin Tong·Gang Chen·Jun Zhao
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Abstract

We report thermodynamic and neutron scattering measurements of the triangular-lattice quantum Ising magnet TmMgGaO 4 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 fluctuations 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.

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Yayuan Qin, Yao Shen, Changle Liu, Hongliang Wo, Yonghao Gao, Yu Feng, Xiaowen Zhang, Gaofeng Ding, Yiqing Gu, Qisi Wang, Shoudong Shen, Helen C. Walker, Robert Bewley, Jianhui Xu, Martin Boehm, Paul Steffens, Seiko Ohira-Kawamura, Naoki Murai, Astrid Schneidewind, Xin Tong, Gang Chen, Jun Zhao. 2020-11-18. Field-Tuned Quantum Effects in a Triangular-Lattice Ising Magnet. https://doi.org/10.1016/j.scib.2021.08.012

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