Dynamics of interatomic Coulombic decay in neon dimers by XUV-pump–XUV-probe spectroscopy

Abstract

We apply the Monte Carlo wave-packet approach to study the interatomic Coulombic decay (ICD) dynamics of neon dimers after removing a 2s electron from one of the Ne atoms by one-photon absorption from an XUV pulse. This method reproduces well both the lifetime for the 2s inner-valence vacancy in Ne 2 + (2s −1) and the kinetic energy release (KER) spectra for the coincident Ne + and Ne 2+ fragments following triple ionization, i.e., two photoionizations and one ionization via ICD, of Ne 2 measured in an XUV-pump-XUV-probe experiment [K. Schnorr et al., Phys. Rev. Lett. 111, 093402 (2013)]. Comparisons between the calculated and measured nuclear KER spectra give physical insights in the considered process. For example, an analysis of the ratios between the low-and high-energy peaks in the nuclear KER spectra for large delays provides an estimate of the photoionization cross sections for removing a 2p electron from the excited states in Ne 2 + (2s −1). Such comparisons also allow an estimate for the ICD rates for the 2s inner-valence vacancy in the single-site two hole state in Ne 2 2+ (2s −1 2p −1). Finally, the influence of photon statistics of the free electron laser pulses on the nuclear KER spectra is considered.

Time-resolved spectroscopy of interparticle Coulombic decay processes

“…Fano profiles of a much faster autoionization (AI) process were recently measured [27,28]. A few time-resolved investigations of ICD have already been performed theoretically and experimentally, where the ions produced in the process were measured [29][30][31][32][33][34][35][36]. However, electrons can be measured with higher energy resolution than ions and grant direct access to the electron dynamics and interference effects during the process.…”

Interatomic and Intermolecular Coulombic Decay

“… 7 A more detailed theoretical study of the nuclear dynamics using a wave packet-approach has been published recently. 352 Just recently, Schmid et al performed a similar pump–probe experiment to trace charge transfers in argon dimers employing strong IR-light as a probe. 324 …”

“…7 A more detailed theoretical study of the nuclear dynamics using a wave packet-approach has been published recently. 352 Just recently, Schmid et al performed a similar pump−probe experiment to trace charge transfers in argon dimers employing strong IR-light as a probe. 324 In an experiment, Takanashi and co-workers used XUVpump and UV-probe pulses to perform a time-resolved study of ICD in doubly excited neon dimers.…”