水二聚体单电离后的反应路径

Laser-induced Electron-Transfer in the Dissociative Multiple Ionization of Argon Dimers

We report on an experimental and theoretical study of the ionization-fragmentation dynamics of argon dimers in intense few-cycle laser pulses with a tagged carrier-envelope phase. We find that a field-driven electron transfer process from one argon atom across the system boundary to the other argon atom triggers sub-cycle electron-electron interaction dynamics in the neighboring atom. This attosecond electron-transfer process between distant entities and its implications manifest themselves as a distinct phase-shift between the measured asymmetry of electron emission curves of the $\text{Ar}^{…

Observation and dynamic control of a new pathway of H$_3^+$ formation

We propose and experimentally demonstrate that the trihydrogen cation (H$_3^+$) can be produced via single photoionization of the molecular hydrogen dimer (H$_4$). Using near-infrared, femtosecond laser pulses and coincidence momentum imaging, we find that the dominant channel after single ionization of the dimer is the ejection of a hydrogen atom within a few hundred femtoseconds, leaving an H3+ cation behind. The formation mechanism is supported and well reproduced by an ab-initio molecular dynamics simulation. This is a new pathway of H$_3^+$ formation from ultracold hydrogen gas that may h…

(H$_2$O)$_n$ (n=1-4) 强场电离和解离动力学中的尺寸效应

Size Effects in the Strong-Field Ionization and Dissociation Dynamics of (H$_2$O)$_n$ (n=1-4)

利用实时含时密度泛函理论结合埃伦费斯特分子动力学，研究水团簇尺寸对强场电离和解离动力学的影响，发现质子响应和氧响应随尺寸显著变化，且质子转移和氢喷射活性在二聚体以上急剧增强。

High activity of He droplets following ionization of systems inside those droplets

Relaxation processes following inner-valence ionization of a system can be modified dramatically by embedding this system in a suitable environment. Surprisingly, such an environment can be even composed of helium atoms, the most inert species available. As demonstrated by the examples of Ne and Ca atoms embedded in He droplets, a fast relaxation process [Interatomic Coulombic Decay (ICD)] takes place merely due to the presence of the He surroundings. We have computed ICD widths for both 4He_N and 3He_N droplets doped with Ne and Ca and discuss the findings in some detail. In the case of Ne, I…

Pure Molecular Beam of Water Dimer

Spatial separation of water dimer from water monomer and larger water-clusters through the electric deflector is presented. A beam of water dimer with $93~\%$ purity and a rotational temperature of $1.5~$K was obtained. Following strong-field ionization using a $35~$fs laser pulse with a wavelength centered around $800~$nm and a peak intensity of $10^{14}~\text{W}/\text{cm}^2$ we observed proton transfer and $46~\%$ of the ionized water dimer broke apart into a hydronium ion $\text{H}_3\text{O}^+$ and neutral OH.

Coulombic Energy Transfer and Triple Ionization in Clusters

Using neon and its dimer as a specific example, it is shown that excited Auger decay channels that are electronically stable in the isolated monomer can relax in a cluster by electron emission. The decay mechanism, leading to the formation of a tricationic cluster, is based on an efficient energy-transfer process from the excited, dicationic monomer to a neighbor. The decay is ultrafast and expected to be relevant to numerous physical phenomena involving core holes in clusters and other forms of spatially extended atomic and molecular matter.

Rearrangements of Water Dimer and Hexamer

Rearrangement mechanisms of the water dimer and the cage form of the water hexamer are examined theoretically with particular reference to tunneling splittings and spectroscopy. The three lowest barrier rearrangements of the water dimer are characterized by {\it ab initio} methods and compared with the results of previous constrained calculations. The acceptor-tunneling pathway does not proceed via a direct rotation around the $C_2$ axis of the acceptor, but rather via relatively asynchronous rotation of the donor about the hydrogen bond and an associated `wag' of the acceptor. Rearrangements …

原子间库仑衰变起始于氦离子和氩双聚体碰撞中的电子移除和激发过程

Interatomic Coulombic decay initiated by electron removal and excitation processes in helium ion and argon dimer collisions

研究了氦离子和氩双聚体碰撞中促进原子间库仑衰变的电子移除和激发通道，通过统计技术分析电子激发路径，发现3d激发态是主要衰变通道，且随着碰撞能量变化，静态和动态势模型存在差异。

为低温充电：超流氦纳米液滴中双电荷与三电荷富勒烯二聚体的形成

Charging up the cold: Formation of doubly- and triply-charged fullerene dimers in superfluid helium nanodroplets

该研究在超流氦纳米液滴中通过顺序电离与高效冷却，发现双电荷和三电荷富勒烯的最小稳定团簇为二聚体，并由计算验证其异构稳定性与低库仑势垒。

臭氧的单光子双电离

Single-Photon Double Ionization of Ozone

研究通过实验和理论方法揭示臭氧双光子电离的电子结构和动力学，发现其电离过程产生激发态阳离子氧碎片，扩展了对大气电离过程的理解。

Ion impact induced Interatomic Coulombic Decay in neon and argon dimers

We investigate the contribution of Interatomic Coulombic Decay induced by ion impact in neon and argon dimers (Ne$_2$ and Ar$_2$) to the production of low energy electrons. Our experiments cover a broad range of perturbation strengths and reaction channels. We use 11.37 MeV/u S$^{14+}$, 0.125 MeV/u He$^{1+}$, 0.1625 MeV/u He$^{1+}$ and 0.150 MeV/u He$^{2+}$ as projectiles and study ionization, single and double electron transfer to the projectile as well as projectile electron loss processes. The application of a COLTRIMS reaction microscope enables us to retrieve the three-dimensional momentu…

氦纳米液滴上异核碱金属二聚体的激光诱导库仑爆炸

Laser-induced Coulomb explosion of heteronuclear alkali dimers on helium nanodroplets

本文利用符合过滤方法从同核与异核碱金属二聚体混合物的库仑爆炸信号中分离出异核二聚体的动能分布，并据此确定核间距分布，以 LiK 和 NaK 为例验证了方法有效性。