Understanding the evolution of molecular electronic structures is the key to explore and control photochemical reactions and photobiological processes. Subjected to strong laser fields, electronic holes are formed upon ionization and evolve in the attosecond timescale. It is crucial to probe the electronic dynamics in real time with attosecond-temporal and atomic-spatial precision. Here, we present molecular attosecond interferometry that enables the in situ manipulation of holes in carbon dioxide molecules via the interferometry of the phase-locked electrons (propagating in opposite directions) of a laser-triggered rotational wave packet. The joint measurement on high-harmonic and terahertz spectroscopy (HATS) provides a unique tool for understanding electron dynamics from picoseconds to attoseconds. The optimum phases of two-color pulses for controlling the electron wave packet are precisely determined owing to the robust reference provided with the terahertz pulse generation. It is noteworthy that the contribution of HOMO-1 and HOMO-2 increases reflecting the deformation of the hole as the harmonic order increases. Our method can be applied to study hole dynamics of complex molecules and electron correlations during the strong-field process. The threefold control through molecular alignment, laser polarization, and the two-color pulse phase delay allows the precise manipulation of the transient hole paving the way for new advances in attochemistry.

Yindong Huang

Jing Zhao

Zheng Shu

Yalei Zhu

Jinlei Liu

Wenpu Dong

Xiaowei Wang

Zhihui L&#x00FC;

Dongwen Zhang

Jianmin Yuan

Jing Chen

Zengxiu Zhao

Ultrafast Hole Deformation Revealed by Molecular Attosecond Interferometry

Matters are generally classified within four states: solid, liquid, gas, and plasma. Three of the four states of matter (solid, gas, and plasma) have been used for THz wave generation with short laser pulse excitation for decades, including the recent vigorous development of THz photonics in gases (air plasma). However, the demonstration of THz generation from liquids was conspicuously absent. It is well known that water, the most common liquid, is a strong absorber in the far infrared range. Therefore, liquid water has historically been sworn off as a source for THz radiation. Recently, broadband THz wave generation from a flowing liquid target has been experimentally demonstrated through laser-induced microplasma. The liquid target as the THz source presents unique properties. Specifically, liquids have the comparable material density to that of solids, meaning that laser pulses over a certain area will interact with three orders more molecules than an equivalent cross-section of gases. In contrast with solid targets, the fluidity of liquid allows every laser pulse to interact with a fresh area on the target, meaning that material damage or degradation is not an issue with the high-repetition rate intense laser pulses. These make liquids very promising candidates for the investigation of high-energy-density plasma, as well as the possibility of being the next generation of THz sources.

Yiwen E

Liangliang Zhang

Anton Tcypkin

Sergey Kozlov

Cunlin Zhang

X.-C. Zhang

Broadband THz Sources from Gases to Liquids

Qihuang Gong

Wei Zhao

Ultrafast Science to Capture Ultrafast Motions

About this journal

The Open Access journal Ultrafast Science, published in association with&nbsp;Xi’an Institute of Optics and Precision Mechanics, is a&nbsp;platform for cutting-edge and emerging topics in ultrafast science with broad interest from scientific communities.

Journal profile

Meet the editorial board

Ultrafast Science's editorial board is led by Qihuang Gong (Peking University)&nbsp;and Wei Zhao (Xi'an Institute of Optics and Precision Mechanics, CAS),&nbsp;and is comprised of experts who have made significant and well recognized contributions to the field of ultrafast science.

Editorial board

More special issue details

Ultrafast Science is now accepting submissions for its first special issue:

<a href="https://spj.sciencemag.org/ultrafast-science-special-issues/attosecond/">Attosecond Science and Technology</a>