Exploring the weakest bond: Structure and ionization of the Helium Dimer, Trimer and the search for the Efimov State

探索最弱的键：氦二聚体、三聚体的结构和电离以及 Efimov 态的搜索

• 批准号: 115609961
• 负责人: Professor Dr. Reinhard Dörner
• 金额: --
• 依托单位: Institut für Kernphysik
• 依托单位国家: 德国
• 项目类别: Reinhart Koselleck Projects
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/115609961?language=en
• 关键词: Exploring; weakest; bond; Structure; ionization

Molecules made of only two Helium atoms (Dimers, He2) and three atoms (Trimers, He3) are extremely fragile, floppy and diffuse quantum objects. The Helium dimer has the by far longest and weakest bond ever observed. It spreads over 100 times the atomic diameter. For the trimer an excited halo state, a so called Efimov state, is predicted but not yet found experimentally. The fascinating quantum nature of the dimer and trimer resulted in a large body of often controversial theoretical work. Experimentally so far only the existence of the dimer and ground state trimer and the mean value of the internuclear distance could be established. The current project suggests a completely new approach to study these objects: we will ionize them with synchrotron radiation, short laser pulses and free electron laser beams to explore their ionization dynamics, image their structure via Coulomb explosion imaging and search for the elusive Efimov state. These unique studies will become possible by putting the dimer and trimer in a COLTRIMS reaction microscope, a multiparticle imaging system, to which the applicant has made major contributions. We will obtain a direct image of the geometrical structure and internuclear distances of the ground state, allowing us to settle the theoretical controversies and providing the most sensitive and background free signal for a search for the Efimov state.

仅由两个氦原子（二聚体，He2）和三个原子（三聚体，He3）组成的分子是极其脆弱、松散和扩散的量子物体。氦二聚体的化学键是迄今为止所观察到的最长、最弱的。它的扩散超过原子直径的100倍。对于三聚体，一个激发态，即所谓的叶菲莫夫态，是预测的，但尚未在实验中发现。二聚体和三聚体令人着迷的量子性质导致了大量经常有争议的理论工作。实验迄今为止，只能确定二聚体和基态三聚体的存在以及核间距离的平均值。目前的项目提出了一种全新的方法来研究这些物体：我们将用同步辐射、短激光脉冲和自由电子激光束电离它们，以探索它们的电离动力学，通过库仑爆炸成像成像它们的结构，并寻找难以捉摸的叶菲莫夫态。通过将二聚体和三聚体置于COLTRIMS反应显微镜中，这些独特的研究将成为可能，COLTRIMS是一种多粒子成像系统，申请人对此做出了重大贡献。我们将获得基态几何结构和核间距离的直接图像，使我们能够解决理论争议，并为寻找叶菲莫夫态提供最敏感和无背景的信号。

项目成果

Numerical Simulations of Single Photon Double Ionization of the Helium Dimer

氦二聚体单光子双电离的数值模拟

• DOI: 10.1103/physreva.88.013407
• 发表时间: 2013
• 期刊: Bulletin of the American Physical Society
• 作者: C. Ruiz;R. Dörner;A. Becker
• 通讯作者: A. Becker

Angular distributions of photoelectrons and interatomic-Coulombic-decay electrons from helium dimers: Strong dependence on the internuclear distance

• DOI: 10.1103/physreva.82.063405
• 发表时间: 2010-12-10
• 期刊: PHYSICAL REVIEW A
• 影响因子: 2.9
• 作者: Havermeier, T.;Kreidi, K.;Jahnke, T.
• 通讯作者: Jahnke, T.

Imaging of the structure of the argon and neon dimer, trimer, and tetramer.

• DOI: 10.1021/jp1121245
• 发表时间: 2011-03
• 期刊: The journal of physical chemistry. A
• 作者: B. Ulrich;A. Vredenborg;Abdollah Malakzadeh;L. Schmidt;T. Havermeier;M. Meckel;K. Cole;M. Smolarski;Z. Chang;T. Jahnke;R. Dörner

Probing angular correlations in sequential double ionization.

• DOI: 10.1103/physrevlett.107.113003
• 发表时间: 2011-09
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Avner Fleischer;Hans Jakob Wörner;L. Arissian;Lee R. Liu;M. Meckel;A. Rippert;R. Dörner;D. M. Villeneuve;P. Corkum;A. Staudte

Multiple recapture of electrons in multiple ionization of the argon dimer by a strong laser field.

• DOI: 10.1103/physrevlett.107.043003
• 发表时间: 2011-07
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Jian Wu;A. Vredenborg;B. Ulrich;L. Schmidt;M. Meckel;S. Voss;H. Sann;H. Kim;T. Jahnke