KNbO₃与KTaNbO₃的普克尔斯响应的实验约束建模
Experimentally constrained modeling of the Pockels response of KNbO3 and KTaNbO3
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中文总结 AI 辅助
该研究针对KNbO₃与KTN的普克尔斯响应，结合从头算与远红外测量，提出实验约束建模方法，发现KTN的TO斯莱特模主导r₅₁普克尔斯系数，其调制器有望替代铌酸锂和BTO技术。
中文摘要 AI 辅助
电光（EO）金属氧化物钙钛矿的软模在决定其普克尔斯响应中起关键作用，钽铌酸钾（KTN）便是如此，其本征普克尔斯响应是当前最先进的钛酸钡（BTO）的2.5倍，凸显了其在高性能EO应用中的潜力。通过结合密度泛函理论级别的从头算与远红外测量，我们发现简谐近似结合半局域交换关联泛函无法准确捕获铌酸钾和KTN的软横光学（TO）斯莱特模，该模主导着技术上相关的r₅₁普克尔斯系数。将计算得到的模频率替换为测量值，提供了一种实验约束方法，可大幅提升普克尔斯响应的预测精度。为此，从远红外反射率测量中提取了此前未报道的KTN的TO斯莱特模频率。结果强调，基于KTN的EO调制器有望替代标准的铌酸锂和BTO技术，具备更低的能耗和器件尺寸。
英文摘要
The soft-mode of electro-optic (EO) metal-oxide perovskites plays a critical role in determining their Pockels responses. This is the case of potassium tantalate niobate (KTN), which exhibits an intrinsic Pockels response 2.5 times larger than that of state-of-the-art barium titanate (BTO), highlighting its potential for high-performance EO applications. By combining ab initio calculations at the density-functional theory level and far-IR measurements, we reveal that the harmonic approximation combined with semi-local exchange-correlation functionals fails to accurately capture the soft transverse optical (TO) Slater mode of both potassium niobate and KTN, which dominates the technologically relevant r51 Pockels coefficient. Replacing the calculated mode frequency with its measured value provides an experimentally constrained approach that substantially improves the predicted Pockels response. For that purpose, the previously unreported TO Slater-mode frequency of KTN is extracted from far-IR reflectivity measurements. The results emphasize the potential of KTN-based EO modulators as an alternative to standard lithium niobate and BTO technologies, with a potentially lower energy consumption and device footprint.
发表机构
- ETH Zurich（苏黎世联邦理工学院）
- University of Bremen（不来梅大学）
- Czech Academy of Sciences（捷克科学院）
机构由 AI 辅助整理，请以论文原文为准。
