Non-Hermitian Quantum Mechanics for High-Order Harmonic Generation Spectra†
Non-Hermitian Quantum Mechanics for High-Order Harmonic Generation Spectra†
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DOI：
10.1021/jp034390y
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发表时间：
2003-06
影响因子：
2.9
通讯作者：
N. Moiseyev;M. Lein
中科院分区：
文献类型：
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作者：
N. Moiseyev;M. Lein
原子和分子在强激光场中的高次谐波产生光谱显示出奇次谐波的宽平台，光子能量高到软X射线区域。导致其他频率，即所谓的超拉曼线或边带消失的机制仍然不清楚。利用多电子原子/分子哈密顿系统的非厄米量子力学，导出了高次谐波产生谱的封闭表达式。对这些表达式的分析提供了超拉曼线缺失的（已知的）条件以及它们可观察到的条件。这里获得的新信息证明，为了观察边带，它是不足以填充两个不同的Floquet状态。当激光脉冲的持续时间足够长时，两个共振Floquet态应该具有相似的宽度（逆寿命）。对于短脉冲，可观察边带的条件更复杂，并且…
High-order harmonic generation spectra of atoms and molecules in intense laser fields show a wide plateau of odd harmonics, with photon energies high up to the soft X-ray regime. The mechanism leading to the absence of other frequencies, so-called hyper-Raman lines or sidebands, is still unclear. By the use of non-Hermitian quantum mechanics for the many-electron atomic/molecular Hamiltonian system, we derive closed-form expressions for the high-order harmonic generation spectra. The analysis of these expressions provides the (already known) conditions for which the hyper-Raman lines are missing and also the conditions for which they are observable. The new information obtained here is proof that in order to observe sidebands it is not sufficient to populate two different Floquet states. When the duration of the laser pulse is sufficiently long, the two resonance Floquet states should have similar widths (inverse lifetimes). For short pulses, the condition for observable sidebands is more complicated, and...