Time-resolved study of resonant interatomic Coulombic decay in helium nanodroplets
A. C. LaForge, R. Michiels, Y. Ovcharenko, A. Ngai, J. M. Escartin, N. Berrah, C. Callegari, A. Clark, M. Coreno, R. Cucini, M. Di Fraia, M. Drabbels, E. Fassha… 展开作者
A. C. LaForge, R. Michiels, Y. Ovcharenko, A. Ngai, J. M. Escartin, N. Berrah, C. Callegari, A. Clark, M. Coreno, R. Cucini, M. Di Fraia, M. Drabbels, E. Fasshauer, P. Finetti, L. Giannessi, C. Grazioli, D. Iablonskyi, B. Langbehn, T. Nishiyama, V. Oliver, P. Piseri, O. Plekan, K. C. Prince, D. Rupp, S. Stranges, K. Ueda, N. Sisourat, J. Eloranta, M. Pi, M. Barranco, F. Stienkemeier, T. Moeller, M. Mudrich
When weakly-bound complexes are multiply excited by intense electromagnetic radiation, energy can be exchanged between neighboring atoms through a type of resonant interatomic Coulombic decay (ICD). This decay mechanism due to multiple excitations has been predicted to be relatively slow, typically lasting tens to hundreds of picoseconds. Here, we directly measure the ICD timescale in resonantly excited helium droplets using a high resolution, tunable, extreme ultraviolet free electron laser. Over an extensive range of droplet sizes and laser intensities, we discover the decay to be surprisingly fast, with decay times as fast as 400 femtoseconds, and to only present a weak dependence on the density of the excited states. Using a combination of time dependent density functional theory and ab initio quantum chemistry calculations, we elucidate the mechanisms of this ultrafast decay process where pairs of excited helium atoms in one droplet strongly attract each other and form merging void bubbles which drastically accelerates ICD.
Time-Resolved Measurement of Interatomic Coulombic Decay in Ne_2
原子间库仑衰变（ICD）寿命[L. S. Cederbaum等人，物理修订版信函79，4778（1997）]在汉堡的自由电子激光中通过极紫外泵浦-探测实验测定。泵浦脉冲在两个Ne原子中的一个中产生了2s的内壳层空位，于是电离的二聚体经历ICD，导致排斥的Ne^{+}（2 p ^{-1}）- Ne^{+}（2 p ^{-1}）态，用第二个脉冲探测该态，去除另外的电子。这使得我们能够推断出Ne_{2} ^{+}（2s^{-1}）态的ICD寿命为（150 +/-50）fs，与量子计算一致。
Vibrationally Resolved Decay Width of Interatomic Coulombic Decay in HeNe
我们研究了氦氖从低于He 1s3p激发到He电离阈值的电离。我们观察到氦氖$^+$离子的增强超过60倍时，他侧共振耦合到辐射场。这些离子是Najjari等人[Phys. Rev. Lett. 105，153002（2010）]。此外，我们的数据提供了电子和振动态分辨的衰变宽度的原子间库仑衰变（ICD）的HeNe二聚体。我们发现，ICD的寿命强烈增加，增加振动状态。
