Crystal-Field Splitting and Correlation Effect on the Electronic Structure of A2IrO3
Crystal-Field Splitting and Correlation Effect on the Electronic Structure of A2IrO3
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DOI：
10.1103/physrevlett.110.076402
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发表时间：
2013-02-13
影响因子：
8.6
通讯作者：
Kim, Young-June
中科院分区：
文献类型：
--
作者：
Gretarsson, H.;Clancy, J. P.;Kim, Young-June
采用共振非弹性x射线散射（RIXS）研究了蜂窝晶格铱酸盐Na2IrO3和Li2IrO3的电子结构。在高分辨率RIXS光谱中可以分辨出晶体场分裂d-d激发。特别是，由j(eff) = 3/2态的分裂得到的非立方晶体场的分裂比典型的自旋轨道能量尺度小得多，验证了jeff物理在A(2)IrO(3)中的适用性。我们还发现在0.4 eV附近粒子-空穴激发间隙的激子增强，表明最近邻的库仑相互作用可能很大。这些发现表明，Na2IrO3和Li2IrO3都可以被描述为自旋轨道莫特绝缘体，类似于方形晶格铱酸盐Sr2IrO4。DOI: 10.1103 / PhysRevLett.110.076402
The electronic structure of the honeycomb lattice iridates Na2IrO3 and Li2IrO3 has been investigated using resonant inelastic x-ray scattering (RIXS). Crystal-field-split d-d excitations are resolved in the high-resolution RIXS spectra. In particular, the splitting due to noncubic crystal fields, derived from the splitting of j(eff) = 3/2 states, is much smaller than the typical spin-orbit energy scale in iridates, validating the applicability of jeff physics in A(2)IrO(3). We also find excitonic enhancement of the particle-hole excitation gap around 0.4 eV, indicating that the nearest-neighbor Coulomb interaction could be large. These findings suggest that both Na2IrO3 and Li2IrO3 can be described as spin-orbit Mott insulators, similar to the square lattice iridate Sr2IrO4. DOI: 10.1103/PhysRevLett.110.076402