论文标题
触发物中的电荷传递能量:硬X射线光电学光谱研究
Charge transfer energy in iridates: a hard x-ray photoelectron spectroscopy study
论文作者
论文摘要
我们使用硬X射线光电子光谱法研究了包含IR $^{4+} $或IR $^{5+} $的双钙钛矿晶体结构中的虹膜物质的电子结构。可以使用紧密的绑定计算(包括IR $ 5D $,o $ 2p $和o $ 2S $轨道)的实验价频段光谱可以很好地再现,并基于对密度功能功能型频带结构的下折叠的折叠。我们发现,无论A和B阳离子如何,A $ _2 $ biro $ _6 $ iridates基本上零o $ 2p $ $ $ 2p $ to $ $ 5D $充电转移能量。因此,双重钙钛矿的生机源是极其共价的系统,结果是磁交换相互作用变得非常长,从而阻碍了长期追求的基塔夫物理学的物质化。然而,使用虹膜液通过对各种竞争交流相互作用进行适当的调整,仍然可以实现旋转液体系统。
We have investigated the electronic structure of iridates in the double perovskite crystal structure containing either Ir$^{4+}$ or Ir$^{5+}$ using hard x-ray photoelectron spectroscopy. The experimental valence band spectra can be well reproduced using tight binding calculations including only the Ir $5d$, O $2p$ and O $2s$ orbitals with parameters based on the downfolding of the density-functional band structure results. We found that regardless of the A and B cations, the A$_2$BIrO$_6$ iridates have essentially zero O $2p$ to Ir $5d$ charge transfer energies. Hence, double perovskite iridates turn out to be extremely covalent systems with the consequence being that the magnetic exchange interactions become very long-ranged, thereby hampering the materialization of the long-sought Kitaev physics. Nevertheless, it still would be possible to realize a spin-liquid system using the iridates with a proper tuning of the various competing exchange interactions.