论文标题
局部结构扭曲在j = 1/2伪旋转状态的起源中的作用
Role of local structural distortions on the origin of j=1/2 pseudo-spin state in sodium iridate
论文作者
论文摘要
Na2iro3（NiO）已知是自旋轨道（SO）驱动的J = 1/2伪旋转Mott-Hubbard（M-H）绝缘子。但是，尚未清楚地理解伪旋转状态的微观起源和局部结构扭曲的作用。利用理论计算和X射线光谱的组合，我们表明，费米水平（EF）附近的能量学由SO相互作用，电子相关和局部八面体畸变控制。与较早的理解相反，我们在这里表明j = 3/2和1/2伪旋转状态具有由于局部结构失真而导致的T2G和EG字符的混合。局部八面体对称性的还原还可以使IR 5D-O2P周围的EF周围杂交，从而产生具有增强电荷转移特征的M-H绝缘子。 Slater绝缘体相的可能性也通过在价带光谱中缺乏室温DOS的结合，计算的矩和温度依赖性磁化测量结果来排除。
Na2IrO3 (NIO) is known to be a spin-orbit (SO) driven j=1/2 pseudo-spin Mott-Hubbard (M-H) insulator. However, the microscopic origin of the pseudo-spin state and the role of local structural distortions have not been clearly understood. Using a combination of theoretical calculations and x-ray spectroscopy, we show that the energetics in the vicinity of Fermi level (EF) is governed by SO interactions, electron correlation and local octahedral distortions. Contrary to the earlier understanding, here we show that the j=3/2 and 1/2 pseudo-spin states have admixture of both t2g and eg characters due to local structural distortion. Reduction of local octahedral symmetry also enables Ir 5d- O2p hybridization around the EF resulting in a M-H insulator with enhanced charge transfer character. The possibility of Slater insulator phase is also ruled out by a combination of absence of room temperature DoS in valence band spectra, calculated moments and temperature dependent magnetization measurements.
