论文标题
固体$ \ rm \ bf c_ {60} $中的高阶谐波生成
High-order harmonic generation in solid $\rm \bf C_{60}$
论文作者
论文摘要
高谐波产生（HHG）释放了固体中强激光物理的力量。在这里，我们从一个大型系统中调查了HHG，固体c $ _ {60} $，在每个水晶动量（第一个水晶动量）中，240个价电子吸引谐波生成。我们采用密度功能理论和密度矩阵的时间依赖性liouville方程来计算HHG信号。我们发现，在适度强的激光脉冲下，HHG信号达到第15阶，与C $ _ {60} $等离子体的实验结果一致。由于高对称性，固体C $ _ {60} $中的螺旋依赖性很弱。与一般信念相反，HHG不适合C $ _ {60} $中的频带结构映射。但是，我们找到了使用长波长的机会窗口，在该波长中，通过多光子激发产生谐波。特别是，第五阶的谐波能量遵循价和导带之间的过渡能分散。这一发现有望激发未来的实验研究。
High harmonic generation (HHG) has unleashed the power of strong laser physics in solids. Here we investigate HHG from a large system, solid C$_{60}$, with 240 valence electrons engaging harmonic generation at each crystal momentum, the first of this kind. We employ the density functional theory and the time-dependent Liouville equation of the density matrix to compute HHG signals. We find that under a moderately strong laser pulse, HHG signals reach 15th order, consistent with the experimental results from C$_{60}$ plasma. The helicity dependence in solid C$_{60}$ is weak, due to the high symmetry. In contrast to the general belief, HHG is unsuitable for band structure mapping in C$_{60}$. However, we find a window of opportunity using a long wavelength, where harmonics are generated through multiple-photon excitation. In particular, the 5th order harmonic energies closely follow the transition energy dispersion between the valence and conduction bands. This finding is expected to motivate future experimental investigations.
