论文标题
$ 5D^4 $绝缘子SR $ _3 $ ir $ _2 $ o $ $ _7 $ f $ _2 $
Spin-orbit excitons and electronic configuration of the $5d^4$ insulator Sr$_3$Ir$_2$O$_7$F$_2$
论文作者
论文摘要
在这里，我们报告了顺磁性旋转轨道绝缘子SR $ _3 $ ir $ _2 $ o $ _7 $ _7 $ f $ _2 $通过谐振X射线散射，\ textIt {ab Initio}量子化学计算和模型 - 木制 - 木尔顿量模拟。该材料是独特的$ d^{4} $ ir $^{5+} $ sr $ _3 $ _3 $ ir $ $ _2 $ _2 $ o $ $ _7 $，当时在SRO层中插入Sro层的sro层插入方形晶格IRO $ _ {6} $ sr $ $ $ $ $ _3 $ $ $ __2 $ _2 $ _2 $ ___2时。由于对IR $^{5+} $离子的扭曲很大，我们的计算表明，一个大的单离子各向异性产生$ S $ = 1（$ l {\ live} $ 1，$ j {\ oft} $ 0）地面状态波函数。观察到了$ s_z $ = 0的基础状态的弱耦合的激子模式，并由先前以$ 3D $和$ 4D $过渡金属离子开发的现象学旋转轨道激子模型很好地描述。讨论了我们关于对先前对孔掺杂源的研究的解释的含义，讨论了接近$ d^{4} $填充物的研究。
Here we report on the low-energy excitations within the paramagnetic spin-orbit insulator Sr$_3$Ir$_2$O$_7$F$_2$ studied via resonant inelastic X-ray scattering, \textit{ab initio} quantum chemical calculations, and model-Hamiltonian simulations. This material is a unique $d^{4}$ Ir$^{5+}$ analog of Sr$_3$Ir$_2$O$_7$ that forms when F ions are intercalated within the SrO layers spacing the square lattice IrO$_{6}$ bilayers of Sr$_3$Ir$_2$O$_7$. Due to the large distortions about the Ir$^{5+}$ ions, our computations demonstrate that a large single-ion anisotropy yields an $S$=1 ($L{\approx}$1, $J{\approx}$0) ground state wave function. Weakly coupled, excitonic modes out of the $S_z$=0 ground state are observed and are well-described by a phenomenological spin-orbit exciton model previously developed for $3d$ and $4d$ transition metal ions. The implications of our results regarding the interpretation of previous studies of hole-doped iridates close to $d^{4}$ fillings are discussed.
