Possible proximity of the Mott insulating iridate Na2IrO3 to a topological phase: Phase diagram of the Heisenberg-Kitaev model in a magnetic field
Possible proximity of the Mott insulating iridate Na2IrO3 to a topological phase: Phase diagram of the Heisenberg-Kitaev model in a magnetic field
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DOI：
10.1103/physrevb.83.245104
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发表时间：
2011-06-06
影响因子：
3.7
通讯作者：
Trebst, Simon
中科院分区：
文献类型：
--
作者：
Jiang, Hong-Chen;Gu, Zheng-Cheng;Trebst, Simon
基于最近对层状铱酸盐Na2IrO3的莫特绝缘状态的实验观察，我们讨论了在强自旋-轨道耦合和磁场存在下有效铱矩的可能有序状态。对于指向< 111 >方向的场-垂直于由铱矩形成的六边形晶格-我们发现海森堡和基塔伊夫交换相互作用的组合产生了丰富的相图，其中既有对称破缺的磁有序相，也有在小耦合参数范围内稳定的拓扑有序相。我们的数值模拟进一步表明在这些有序相的边界处有两个奇异的临界点。
Motivated by the recent experimental observation of a Mott insulating state for the layered iridate Na2IrO3, we discuss possible ordering states of the effective iridium moments in the presence of strong spin-orbit coupling and a magnetic field. For a field pointing in the < 111 > direction-perpendicular to the hexagonal lattice formed by the iridium moments-we find that a combination of Heisenberg and Kitaev exchange interactions gives rise to a rich phase diagram with both symmetry breaking magnetically ordered phases as well as a topologically ordered phase that is stable over a small range of coupling parameters. Our numerical simulations further indicate two exotic critical points at the boundaries between these ordered phases.