论文标题
一维周期晶体中高阶谐波的光谱苛刻
Spectral caustics of high-order harmonics in one-dimensional periodic crystals
论文作者
论文摘要
从理论上讲，我们研究了固体中高阶谐波的光谱腐蚀性。我们分析了固体HHG的1维模型，并发现除了属于能量波段结构中的范霍夫奇异点外，另一种灾难性的奇异性也出现了，当电子孔轨迹的不同分支产生高阶谐波凝胶的不同分支中。我们在周期性的潜力中求解了时间依赖性的schrödinger方程，并用两色激光场的辅助设置了对HHG中这种奇异性的控制。焦点附近的谐波光谱的衍射模式与半导体半古典方程预测的带间电子重组轨迹非常吻合。预计这项工作将有助于了解固体中的HHG动力学，并通过调整驱动场参数来操纵谐波频谱。
We theoretically investigate the spectral caustics of high-order harmonics in solids. We analyze the 1-dimension model of solids HHG and find that, apart from the caustics originated from the van Hove singularities in the energy-band structure, another kind of catastrophe singularities also emerge when the different branches of electron-hole trajectories generating high-order harmonics coalesce into a single branch. We solve time-dependent Schrödinger equation in periodic potential and demonstrate the control of this kind of singularities in HHG with the aids of two-color laser fields. The diffraction patterns of the harmonic spectrum near the caustics agree well with the inter-band electron-hole recombination trajectories predicted by the semiconductor semi-classical equation. This work is expected to help to understand the HHG dynamics in solids and manipulate the harmonic spectrum by adjusting driving field parameters.
