论文标题
Kitaev Quantum Quantum-Spin-liquid候选者中的量子路推力h $ _ {3} $ liir $ _ {2} $ o $ $ _ {6} $和d $ _ {3} $ _ {3} $ liir $ _ {2}
Quantum Paraelectricity in the Kitaev Quantum-Spin-Liquid Candidates H$_{3}$LiIr$_{2}$O$_{6}$ and D$_{3}$LiIr$_{2}$O$_{6}$
论文作者
论文摘要
H3LIIR2O6是第一个蜂窝状晶格系统，没有任何远距离磁性的迹象至最低的温度，从而提高了理想的Kitaev量子自旋液体的希望。其蜂窝层与层间氢键结合。提出了这些氢键的静态或动态障碍，以强烈影响磁交换并使Kitaev型相互作用显性占主导地位。使用介电光谱法，我们在这里提供了H3LIIR2O6中偶极弛豫和氘化D3Liir2O6的实验证据，该二皮极弛豫反映了氢键双电势内的质子和德氏蛋白的动力学。检测到的氢动力学揭示了玻璃冰的冻结，其特征是在冷却下放慢速度，从热激活的跳跃到量子力的机械隧道到低温。因此，除了是基塔夫量子旋转的候选者外，这些材料还包括量子paraelectrics。然而，在低温下发现的MHz范围内的较小放松率实际上实现了准静态氢障碍，这是在最近的理论著作中假定的，以解释两种化合物的量子旋转基态。
H3LiIr2O6 is the first honeycomb-lattice system without any signs of long-range magnetic order down to the lowest temperatures, raising the hope for the realization of an ideal Kitaev quantum spin liquid. Its honeycomb layers are coupled by interlayer hydrogen bonds. Static or dynamic disorder of these hydrogen bonds was proposed to strongly affect the magnetic exchange and to make Kitaev-type interactions dominant. Using dielectric spectroscopy, here we provide experimental evidence for dipolar relaxations in H3LiIr2O6 and deuterated D3LiIr2O6, which mirror the dynamics of protons and deuterons within the double-well potentials of the hydrogen bonds. The detected hydrogen dynamics reveals glassy freezing, characterized by a strong slowing down under cooling, with a crossover from thermally-activated hopping to quantum-mechanical tunneling towards low temperatures. Thus, besides being Kitaev quantum-spin-liquid candidates, these materials also are quantum paraelectrics. However, the small relaxation rates in the mHz range, found at low temperatures, practically realize quasi-static hydrogen disorder, as assumed in recent theoretical works to explain the quantum-spin-liquid ground state of both compounds.
