论文标题
在两个非磁性五价蜂窝状的电子基态下
On the electronic ground state of two non-magnetic pentavalent honeycomb iridates
论文作者
论文摘要
我们研究了两个IR $^{5+} $ Honeycomb iridates的电子结构，SR $ _3 $ CAIR $ _2 $ o $ _9 $和NAIRO $ _3 $，通过谐振X射线技术。我们确认SR $ _3 $ CAIR $ _2 $ o $ _9 $实现了一个大型旋转轨道驱动的非磁性$ J = 0 $ singlet基态，尽管IR协调八面体的四方扭曲很大。另一方面，NAIAO $ _3 $的共振非弹性X射线光谱与对具有八面体配位的IR $^{5+} $的莫特绝缘子的期望大不相同。我们发现，NAIAO $ _3 $的数据可以最好地解释为源自狭窄的间隙非磁性$ S = 0 $ band绝缘地面状态。我们的结果突出了配体环境在蜂窝虹膜电子结构中的复杂作用，以及X射线光谱法对表征绝缘材料的电子接地态的重要作用。
We investigate the electronic structure of two Ir$^{5+}$ honeycomb iridates, Sr$_3$CaIr$_2$O$_9$ and NaIrO$_3$, by means of resonant x-ray techniques. We confirm that Sr$_3$CaIr$_2$O$_9$ realizes a large spin-orbit driven non-magnetic $J = 0$ singlet ground state despite sizable tetragonal distortions of Ir coordinating octahedra. On the other hand, the resonant inelastic x-ray spectra of NaIrO$_3$ are drastically different from expectations for a Mott insulator with octahedrally coordinated Ir$^{5+}$. We find that the data for NaIrO$_3$ can be best interpreted as originating from a narrow gap non-magnetic $S = 0$ band insulating ground state. Our results highlight the complex role of the ligand environment in the electronic structure of honeycomb iridates and the essential role of x-ray spectroscopy to characterize electronic ground states of insulating materials.
