Ultrafast temporal evolution of interatomic Coulombic decay in NeKr dimers

F Trinter,M Weller,A Gatton,B Berry,N Sisourat,B Gaire,J Sartor,R Dörner,K Gokhberg,T Weber,A Hartung,A L Landers,T Jahnke,T Miteva,J B Williams,I Ben-Itzhak,V Stumpf,M Richter

doi:10.1039/d1sc04630f

Abstract

We investigate interatomic Coulombic decay in NeKr dimers after neon inner-valence photoionization [Ne+(2s−1)] using a synchrotron light source. We measure with high energy resolution the two singly charged ions of the Coulomb-exploding dimer dication and the photoelectron in coincidence. By carefully tracing the post-collision interaction between the photoelectron and the emitted ICD electron we are able to probe the temporal evolution of the state as it decays. Although the ionizing light pulses are 80 picoseconds long, we determine the lifetime of the intermediate dimer cation state and visualize the contraction of the nuclear structure on the femtosecond time scale.

Highlights

We report on a detailed experimental investigation of ICD in NeKr dimers a er Ne+(2sÀ1) photoionization, where we apply the method of post-collision interaction (PCI)-streaking and measure the energy shi of the slow photoelectron in order to infer the time of the decay
We have extended our experimental PCI-streaking approach to resolve ICD in dimers in order to time ultrafast decay dynamics
In contrast to our previous studies on the evolution of ICD in the time domain in homonuclear HeHe dimers,[28] which took place on picosecond time scales, in this work we could successfully track the dynamics in heteronuclear NeKr dimers in the 1000 times faster femtosecond time domain

Summary

Introduction

We examine the temporal evolution of an IC-decaying system. The ICD lifetime of a dimer is rooted in the nature of the transient electronically excited dimer states, i.e., the charge state, the internuclear distance, as well as the steepness and variety of the accessible potential energy curves (PECs). We report on a detailed experimental investigation of ICD in NeKr dimers a er Ne+(2sÀ1) photoionization, where we apply the method of PCI-streaking and measure the energy shi of the slow photoelectron in order to infer the time of the decay. Experimental observables such as the squared norm of the vibrational wave packet and the mean internuclear distance of the decaying electronic state as a function of time can be obtained theoretically To this end, we apply the Born–Oppenheimer approximation to separate the electronic and nuclear degrees of freedom and rst obtain the electronic properties of the dimer, i.e., the adiabatic PECs and the ICD width.

38. The mean internuclear distance and the binding energy of this

Results

Conclusions