Spin Waves and Revised Crystal Structure of Honeycomb Iridate Na2IrO3
Spin Waves and Revised Crystal Structure of Honeycomb Iridate Na2IrO3
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DOI：
10.1103/physrevlett.108.127204
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发表时间：
2012-03-20
影响因子：
8.6
通讯作者：
Taylor, J.
中科院分区：
文献类型：
--
作者：
Choi, S. K.;Coldea, R.;Taylor, J.
我们报告非弹性中子散射测量Na 2 IrO 3，Kitaev自旋模型的蜂窝晶格上的候选人。我们观察到自旋波激发低于5毫电子伏的色散，可以解释为包括大量的进一步的邻居交流，稳定锯齿形磁秩序。通过在零场μ子自旋旋转实验中观察到的振荡，证实了在T-N = 15.3 K以下长程磁序的开始。结合单晶衍射和密度泛函计算，我们提出了一个修订的晶体结构模型，从占主导地位的Kitaev交换所需的理想的90度Ir-O-Ir键显着偏离。
We report inelastic neutron scattering measurements on Na2IrO3, a candidate for the Kitaev spin model on the honeycomb lattice. We observe spin-wave excitations below 5 meV with a dispersion that can be accounted for by including substantial further-neighbor exchanges that stabilize zigzag magnetic order. The onset of long-range magnetic order below T-N = 15.3 K is confirmed via the observation of oscillations in zero-field muon-spin rotation experiments. Combining single-crystal diffraction and density functional calculations we propose a revised crystal structure model with significant departures from the ideal 90 degrees Ir-O-Ir bonds required for dominant Kitaev exchange.