论文标题
LANIO $ _3 $的氧气空位的稳定性和扩散
Stability and diffusion of oxygen vacancies in LaNiO$_3$: a DMFT study
论文作者
论文摘要
在密切相关的稀土镍钙壶（RNIO $ _3 $）中操纵氧空位使其能够调整其难以捉摸的金属绝缘体过渡（MIT），从而更好地控制了对其电子特性的控制。在本文中，我们通过研究其光谱函数以及使用动力学平均场理论（DMFT）和密度功能理论以及u（DFT+U）来研究各种氧空位配置对LANIO $ _3 $ MIT的影响。为了考虑固定空置浓度的所有可能配置，我们使用适应对称的配置集合方法。在此方法中，我们可以减少需要考虑的配置空间，从而降低计算成本。我们证明控制氧空位位置可以调整MIT的发生。我们还表明，使用DMFT获得的弹性弹性带（NEB）能量屏障高度和与使用DFT+U获得的能量曲线相比，由于在DFT+U中未正确处理的非脱位相关轨道中使用DFT+U所获得的能量。
Manipulating oxygen vacancies in strongly correlated rare-earth nickelate perovskites (RNiO$_3$) enables the tuning of their elusive metal-insulator transition (MIT), providing a better handle for control over their electronic properties. In this paper, we investigate the effect of various oxygen vacancy configurations on the MIT of LaNiO$_3$ by studying their spectral functions and the corresponding diffusion energy path using dynamical mean field theory (DMFT) and density functional theory plus U (DFT+U). To consider all possible configurations for a fixed vacancy concentration, we use a symmetry-adapted configurational ensemble method. Within this method, we can reduce the configurational space which needs to be considered, thus lowering the computational cost. We demonstrate that controlling the oxygen vacancy position can tune the occurrence of MIT. We also show that the nudged elastic band (NEB) energy barrier heights and energy profile obtained using DMFT are lower and different than those obtained using DFT+U due to dynamical quantum fluctuations among non-degenerate correlated orbitals not properly treated in DFT+U.
