A new quantum spin liquid (QSL) candidate material H₃LiIr₂O₆ was synthesized recently and was found not to show any magnetic order or phase transition down to low temperatures. In this work, we study the quantum dynamics of the hydrogen ions, i.e., protons, in this material by combining first-principles calculations and theoretical analysis. We show that each proton and its adjacent oxygen ions form an electric dipole. The dipole interactions and the proton tunneling are captured by a transverse-field Ising model with a quantum disordered paraelectric ground state. The dipole excitations have an energy gap Δ_d ≃ 60 meV, and can be probed by the infrared optical spectroscopy and the dielectric response. We argue that the electric dipole fluctuations renormalize the magnetic interactions in H₃LiIr₂O₆ and lead to a Kitaev QSL state.

中文翻译：

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Kitaev自旋液体候选物H 3 LiIr 2 O 6中可能的量子顺电态

最近合成了一种新的量子自旋液体（QSL）候选材料H ₃ LiIr ₂ O ₆，发现在低温下没有任何磁序或相变。在这项工作中，我们通过结合第一性原理计算和理论分析来研究这种材料中氢离子（质子）的量子动力学。我们表明每个质子及其相邻的氧离子形成一个电偶极子。偶极相互作用和质子隧穿被具有量子无序顺电基态的横向场伊辛模型捕获。偶极子激励具有的能隙Δ _dme 60 meV，并且可以通过红外光谱和介电响应进行探测。我们认为电偶极子波动使H ₃ LiIr ₂ O _6中的磁相互作用重新归一化，并导致一个Kitaev QSL状态。