固体强场辐射中布洛赫电子超快动力学研究

High-order harmonic generation (HHG) broaden to vacuum ultraviolet and extreme ultraviolet is an extremely nonlinear electro-optical behavior between the solids and the strong laser field. HHG from solids can not only be the solid-state sources of isolated extreme-ultraviolet pulses, but also can be used to probe the ultrafast electron dynamics and all-optically reconstruct the band structure. Although there are many experimental and theoretical researches, the microscopic mechanism underlying HHG from solids is still controversially debated, due to the high density and the periodic structures of solids. In this project, we focus on the frontiers of the strong field physics in solids. Based on the mechanism of HHG from solids in real space, the instantaneous electron dynamics in solids has been investigated. The synchronized radiation of HHG and terahertz wave (THz) from solids driven by the two-color laser field has also been explored. The coherent control system of electron dynamics in two-dimensional materials is established using the quantum trajectories. This project is of great significance in understanding the mechanism of the strong-field quantum coherent radiation from solids.

强激光场与固体相互作用的极端非线性可以产生真空紫外和极远紫外区的固体高次谐波。固体高次谐波不仅可以作为强阿秒脉冲源，还可以用于探测阿秒尺度电子超快动力学特性和全光学成像固体能带结构信息。虽然固体高次谐波涌现了大量的实验和理论研究，但是由于不同于原子分子，其高密度和周期性的结构特征使得对于固体辐射机制理解尚未明朗。本项目针对固体强场物理这一前沿研究领域中的关键科学问题提出，在固体高次谐波产生的坐标空间物理图像下，深入探究亚光学周期内固体中电子的瞬态动力学特性。揭示双色场驱动下固体高次谐波和太赫兹波协同辐射的物理机制。结合量子轨迹在二维材料中建立电子动力学的相干调控体系。该研究对于深入理解强场驱动固体量子相干辐射的微观动力学机制有重要意义。

强激光场与固体相互作用的极端非线性可以产生真空紫外和极远紫外区的固体高次谐波。固体高次谐波不仅可以作为强阿秒脉冲源，还可以用于探测阿秒尺度电子超快动力学特性和全光学成像固体能带结构信息。本项目针对固体强场物理这一前沿研究领域中的关键科学问题提出，研究内容基本按计划执行。首先基于固体高次谐波多平台结构，通过探测固体中电子的超快动力学特性，分析了动态布洛赫振荡对固体高次谐波高频区域的贡献，从而有效地在固体材料中产生更短阿秒脉冲，实现了固体中电子和空穴动力学更短的时间分辨；其次探究了强激光场作用下固体高次谐波和太赫兹波协同辐射，分析了电子的超快动态局域化在固体强场辐射中的重要作用。成像了电子相干演化的时域信息，从而实现了材料的能带信息的解构。本项目研究结果揭示了固体强场辐射在阿秒光源、晶体结构和能带结构表征等方面的应用，结合相关实验现象为本研究领域提供理论预测。