First-Principles Study of the Magnetic Structure of Na2IrO3
First-Principles Study of the Magnetic Structure of Na2IrO3
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Na2IrO3磁结构的第一性原理研究
DOI：
10.1103/physrevlett.115.167204
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发表时间：
2015-10-16
影响因子：
8.6
通讯作者：
Feng, Ji
中科院分区：
文献类型：
--
作者：
Hu, Kaige;Wang, Fa;Feng, Ji
铱酸盐Na 2 IrO 3被认为是Kitaev模型的量子自旋液体基态的实现。实验已经证实，这种材料具有锯齿形反铁磁序。然而，以前指定的有序的时刻方向的a轴是有争议的。我们研究的磁矩方向Na 2 IrO 3使用本地自旋密度近似加上自旋轨道耦合+ U计算。计算结果表明，当磁有序矩沿沿着g近似a + c方向排列时，总能量最小.总能量对磁矩方向的依赖性可以通过在最近邻Kitaev-Heisenberg模型中加入各向异性相互作用来解释，并在此基础上计算了自旋波谱。有序矩的修正对于理解和获得该化合物中可能的奇异电子相是非常重要的。
The iridate Na2IrO3 was proposed to be a realization of the Kitaev model with a quantum spin liquid ground state. Experiments have now established that this material hosts a zigzag antiferromagnetic order. However, the previous assignment of the ordered moment direction to the a axis is controversial. We examine the magnetic moment direction of Na2IrO3 using the local spin density approximation plus spin orbit coupling + U calculations. Our calculations reveal that the total energy is minimized when the zigzag-ordered moments are aligned along g approximate to a + c direction. The dependence of the total energy on moment directions can be explained by adding anisotropic interactions to the nearest-neighbor Kitaev-Heisenberg model, on which the spin-wave spectrum is also calculated. The revision of ordered moments is very important to understanding and achieving possible exotic electronic phases in this compound.