We employ a theoretical model based on the density-matrix equation in the velocity gauge to calculate high harmonic generation from monolayer MoS 2 . This approach incorporates the tight-binding model, enabling the full consideration of both crystal symmetry and multiple band effects. In additional to the usual odd harmonics, even harmonics are also presented in the case of observing two different polarization components, which are parallel and perpendicular to the polarization of linearly driving pulses. We detailedly analyze the crystal orientation dependence for the parallel and perpendicular components of both odd- and even-harmonics. It is found that they exhibits different modulation behavior with rotating the crystal orientation. The simulation results capture all important orientation-dependent features observed in the recent experiment, thus demonstrating that the Berry curvature of MoS 2 has been appropriately considered in our proposed model. In ord...

中文翻译：

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单层MoS 2中高次谐波产生的极化分辨分析

我们在速度计中采用基于密度矩阵方程的理论模型，以计算单层MoS 2产生的高次谐波。这种方法结合了紧密结合模型，可以全面考虑晶体对称性和多能带效应。除了常见的奇次谐波，在观察两个不同的极化分量时，还会出现偶次谐波，这两个极化分量平行且垂直于线性驱动脉冲的极化。我们详细分析了奇数和偶数谐波的平行和垂直分量的晶体取向依赖性。发现随着晶体取向的旋转它们表现出不同的调制行为。仿真结果捕获了最近实验中观察到的所有重要的方向相关特征，因此表明在我们提出的模型中已经适当考虑了MoS 2的贝里曲率。在...