AI 中文总结
本研究检验DFT+U与DFT+U+V泛函预测非中心对称钙钛矿氧化物光学各向异性的准确性，发现DFT+U+V泛函可提升性能且成本低，还探究了掺杂BaTiO₃固溶体的应用潜力。
AI 中文摘要
光学各向异性是众多光子与量子技术运行及性能的基础。本研究严格检验了含 onsite 与 intersite Hubbard 修正的密度泛函理论近似（即 DFT+$U$ 和 DFT+$U$+$V$ 泛函）在预测非中心对称钙钛矿氧化物（如 BaTiO$_3$、LiNbO$_3$、KNbO$_3$、PbTiO$_3$）各向异性光学响应时的准确性。研究发现，仅用 DFT+$U$ 修正自相互作用误差无法捕捉这些材料的光电响应，常导致其光学各向异性被抑制；而 intersite Hubbard 相互作用虽能恢复该各向异性，但定义 Hubbard 修正的（原子间）原子轨道流形的选择对其准确性至关重要。经系统验证的 DFT+$U$+$V$ 泛函的预测性能，仅为杂化泛函与多体微扰理论计算计算成本的一小部分。作为基准，研究还探究了 Zn 与（Bi,Mn）掺杂的 BaTiO$_3$ 固溶体，其中（Bi,Mn）掺杂样品因带隙中间态引发的极化依赖带隙窄化，显著提升了二向色性比与双折射，对偏振敏感光电探测器与集成光子学具有潜在应用价值。
英文摘要
Optical anisotropy underpins the operation and performance of a broad range of photonic and quantum technologies. In this work, we critically examine the accuracy of density functional theory approximations with onsite and intersite Hubbard corrections (the DFT+$U$ and DFT+$U$+$V$ functionals) in predicting the anisotropic optical response of the non-centrosymmetric perovskite oxides, such as BaTiO$_3$, LiNbO$_3$, KNbO$_3$, and PbTiO$_3$. It is found that correcting self-interaction errors using DFT+$U$ alone does not capture the optoelectronic response of these materials, often leading to a suppression of their optical anisotropy. While intersite Hubbard interactions restore this anisotropy, the choice of the (inter)atomic orbital manifold that defines the Hubbard correction remains critical to its accuracy. The predictive performance of the resulting, systematically validated DFT+$U$+$V$ functional is achieved at a fraction of the computational cost of hybrid functionals and many-body perturbation theory calculations. As benchmarks, we investigate Zn- and (Bi,Mn)-substituted BaTiO$_3$ solid solutions; the latter exhibit polarization-dependent bandgap narrowing from mid-gap states, substantially enhancing the dichroic ratio and birefringence with promising implications for polarization-sensitive photodetectors and integrated photonics.
Comments13 pages, 7 figures + 1-page Supplementary Information (1 figure)
