透明导电氧化物中折射率的极超快动力学：理论与实验
Extreme Ultrafast Dynamics of the Refractive Index in Transparent Conductive Oxides: Theory and Experiment
AI总结：
本文针对透明导电氧化物（TCO）中光诱导折射率的极超快变化问题，建立基于电子微观动力学的简化模型并开展模拟，预测并实验观测到导带内电子带内调制引发的折射率超快振荡，验证了理论的预测性，可用于设计新型极超快现象相关实验。
AI中文摘要：
透明导电氧化物（TCO）的最新实验揭示了光诱导的折射率发生量级为1的变化，且该变化发生在仅几飞秒的极短时间尺度上。这些实验观测结果仍未得到解释，尤其是折射率变化在10-20飞秒的超快弛豫过程，无法用已知的声子介导弛豫机制解释。本文提出了一个简化模型并进行了全面模拟，描述了该现象，模型基于强超快激光脉冲作用下TCO中电子的微观动力学。通过该物理模型，我们预测并实验观测到了导带内电子带内调制的未探索区域，该区域会导致折射率的超快振荡。对该振荡的观测验证了该理论作为预测工具的有效性，利用该理论可设计针对依赖材料光学性质极端改变的新效应的实验，如光子时间晶体以及大量新型极超快现象。
英文摘要：
Recent experiments in transparent conductive oxides (TCOs) have revealed light-induced order-unity variations in the refractive index occurring at extreme time scales, as short as a few-femtoseconds. These experimental observations remain unexplained, especially the ultrafast 10-20 femtoseconds relaxation of the index change, that cannot be explained by known phonon-mediated relaxation processes. Here, we present a simplified model followed by comprehensive simulations describing the phenomena, relying on the microscopic dynamics of electrons in TCOs under powerful ultrafast laser pulses. With this physical model, we predict and experimentally observe the unexplored regime of intraband modulation of electrons in the conduction band, leading to ultrafast oscillations of the refractive index. The observation of the oscillations validates the theory as a predictive tool, utilizing it to design experiments targeting novel effects that hinge on extreme alterations of optical properties of materials, such as photonic time-crystals and a plethora of novel extreme ultrafast phenomena.
