Crystal-momentum-resolved contributions to high-order harmonic generation in solids
Crystal-momentum-resolved contributions to high-order harmonic generation in solids
复制标题
DOI：
10.1103/physreva.100.033405
复制
发表时间：
2019-09-09
影响因子：
2.9
通讯作者：
Thumm, Uwe
中科院分区：
文献类型：
--
作者：
Navarrete, Francisco;Ciappina, Marcelo F.;Thumm, Uwe
我们通过分析和数值研究了强少周期中红外激光脉冲从模型固体发射高阶谐波辐射。在单活性电子近似中，我们在绝热休斯顿态的基础上扩展了活性电子的波函数，并根据可调节的 Kronig-Penney 模型势描述了固体的电子能带结构。对于 MgO 晶体的高阶谐波产生 (HHG)，我们检查了两波段和收敛多波段数值计算的光谱。我们讨论了用于计算的 HHG 谱的带内和带间贡献的特征，包括仅来自第一布里乌林区 (BZ) 中心的 F 点或来自整个第一 BZ 的初始晶体动量。对于足够高强度的驱动激光场，我们发现整个第一 BZ 对 HHG 的相关贡献。基于数值计算的光谱，我们仔细检查了截止谐波阶次作为激光峰值强度的函数，并发现与我们的分析鞍点近似预测和已发表的理论数据具有良好的定性一致性。
We analytically and numerically investigate the emission of high-order harmonic radiation from model solids by intense few-cycle midinfrared laser pulses. In single-active-electron approximation, we expand the active electron's wave function in a basis of adiabatic Houston states and describe the solid's electronic band structure in terms of an adjustable Kronig-Penney model potential. For high-order harmonic generation (HHG) from MgO crystals, we examine spectra from two-band and converged multiband numerical calculations. We discuss the characteristics of intra- and interband contributions to the HHG spectrum for computations including initial crystal momenta either from the F point at the center of the first Brioullin zone (BZ) only or from the entire first BZ. For sufficiently high intensities of the driving laser field, we find relevant contributions to HHG from the entire first BZ. Based on numerically calculated spectra, we scrutinize the cutoff harmonic orders as a function of the laser peak intensity and find good qualitative agreement with our analytical saddle-point-approximation predictions and published theoretical data.