Subband picture of high-harmonic generation in solids
Subband picture of high-harmonic generation in solids
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DOI：
10.1103/physrevb.100.081203
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发表时间：
2019-06
影响因子：
3.7
通讯作者：
T. Tamaya;T. Kato
中科院分区：
文献类型：
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作者：
T. Tamaya;T. Kato
基于能带结构随时间变化的概念，我们提出了一种新的固体高次谐波产生(HHG)图像。为了证明这幅图的实用性，我们在泵浦-探测光谱学的背景下，重点研究了由强太赫兹(THz)和弱近红外(NIR)光引起的高阶边带产生(HSG)。我们发现，HSG的近红外频率依赖关系表明，在具有多个THz光频率的带隙能量周围存在新的能级(子带)。这张子带图像解释了为什么HSG强度成为太赫兹光幅的非单调函数。目前的分析不仅揭示了HHG谱中平台结构的起源，而且还提供了与其他高场现象的联系。
We propose a novel picture of high-harmonic generation (HHG) in solids based on the concept of temporally changing band structures. To demonstrate the utility of this picture, we focus on the high-order sideband generation (HSG) caused by strong terahertz (THz) and weak near-infrared (NIR) light in the context of pump-probe spectroscopy. We find that the NIR frequency dependence of the HSG indicates the existence of new energy levels (sub-bands) around the band-gap energy, which have multiple frequencies of THz light. This sub-band picture explains why the HSG intensity becomes a non-monotonic function of the THz light amplitude. The present analysis not only reveals the origin of the plateau structure in HHG spectra, but also provides a connection to other high-field phenomena.