Controlling quantum effects in enhanced strong-field ionisation with machine-learning techniques
Controlling quantum effects in enhanced strong-field ionisation with machine-learning techniques
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DOI：
10.1088/1361-6455/aca4b0
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发表时间：
2022-05
期刊：
影响因子：
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通讯作者：
H. Chomet;Samuel Plesnik;Constantin Nicolae;Jack Dunham;Lesley Gover;Timothy Weaving;Carla Figueira de Morisson Faria
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文献类型：
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作者：
H. Chomet;Samuel Plesnik;Constantin Nicolae;Jack Dunham;Lesley Gover;Timothy Weaving;Carla Figueira de Morisson Faria
我们利用机器学习技术研究了强激光场中双原子分子增强电离中的非经典路径和量子干涉。量子干涉为分子内布居转移提供了一座“桥梁”。它的频率高于场的频率，这是系统固有的，并且取决于几个因素，例如初始波包的状态或核间分离。利用降维技术，即t分布随机邻域嵌入和主成分分析，我们同时研究了多个参数的影响，找到了静电场中增强电离和双色驱动场受控电离释放的最佳条件。这种受控电离在依赖时间的自相关函数中表现为阶跃行为。我们解释了相空间自变量所遇到的特征，并建立了通过相空间Wigner准概率流控制电离的参数层次，例如状态的特定相干叠加、电子局域化和核间距离范围。
We study non-classical pathways and quantum interference in enhanced ionisation of diatomic molecules in strong laser fields using machine learning techniques. Quantum interference provides a ‘bridge’, which facilitates intramolecular population transfer. Its frequency is higher than that of the field, intrinsic to the system and depends on several factors, for instance the state of the initial wavepacket or the internuclear separation. Using dimensionality reduction techniques, namely t-distributed stochastic neighbour embedding and principal component analysis, we investigate the effect of multiple parameters at once and find optimal conditions for enhanced ionisation in static fields, and controlled ionisation release for two-colour driving fields. This controlled ionisation manifests itself as a step-like behaviour in the time-dependent autocorrelation function. We explain the features encountered with phase-space arguments, and also establish a hierarchy of parameters for controlling ionisation via phase-space Wigner quasiprobability flows, such as specific coherent superpositions of states, electron localisation and internuclear-distance ranges.