意大利米兰理工大学Matteo Lucchini团队研究了电介质中的阿秒虚电荷动力学。相关论文发表在2025年6月16日出版的《自然—光子学》杂志上。
强红外脉冲与固体目标的相互作用可以引发光场驱动现象，从而在阿秒的时间尺度上可逆地操纵它们的电光特性。因此，这种交互机制为以非常高的速度诱导和控制新功能提供了独特的机会。然而，为了在未来的应用中有效地利用相干光-物质状态，需要对潜在的物理过程有详细的了解。固体中场驱动现象背后的真实和虚拟载流子的带间和带内动力学的复杂性和交织性使这项任务变得复杂。研究组使用阿秒瞬态反射光谱来研究原型电介质（单晶金刚石）中在以前未获得的宽光子能量范围内的超快虚电子动力学。
泵浦-探针延迟轴的独立校准实现了与数值计算进行直接比较，揭示了虚拟带间跃迁会影响晶体响应的时序和绝热性，即使在被认为由带内运动主导的情况下也是如此。通过证明虚拟带间跃迁对于准确描述固体中强场诱导现象是不可或缺的，该结果构成了理解瞬态非线性光学过程的重要一步，这是信息处理和太赫兹电子学未来发展的基石。
附：英文原文
Title: Attosecond virtual charge dynamics in dielectrics
Author: Dolso, Gian Luca, Sato, Shunsuke A., Inzani, Giacomo, Di Palo, Nicola, Moio, Bruno, Borrego-Varillas, Roco, Nisoli, Mauro, Lucchini, Matteo
Issue&Volume: 2025-06-16
Abstract: The interaction of intense infrared pulses with a solid target can initiate light-field-driven phenomena that enable the reversible manipulation of their electro-optical properties on an attosecond timescale. This interaction regime therefore offers a unique opportunity to induce and control new functionalities with very high speed. However, the efficient exploitation of coherent light–matter states for future applications requires a detailed understanding of the underlying physical processes. This task is complicated by the complex and intertwined nature of inter- and intraband dynamics of real and virtual carriers underlying field-driven phenomena in solids. Here we used attosecond transient reflection spectroscopy to investigate ultrafast virtual electron dynamics in a prototype dielectric (monocrystalline diamond) over a broad photon energy range not previously accessed. Independent calibration of the pump–probe delay axis allowed direct comparison with numerical calculations, revealing that virtual interband transitions affect the timing and adiabaticity of the crystal response, even in a regime believed to be dominated by intraband motion. By demonstrating that virtual interband transitions are indispensable for an accurate description of strong-field-induced phenomena in solids, our results constitute a relevant step towards understanding transient nonlinear optical processes, a cornerstone for the future development of information processing and petahertz electronics.
DOI: 10.1038/s41566-025-01700-6
Source: https://www.nature.com/articles/s41566-025-01700-6