Ultrafast interatomic electronic decay in multiply excited clusters

TL;DR

This paper proposes an ultrafast interatomic Coulombic decay (ICD) mechanism in excited clusters, showing it dominates ionization over two-photon processes under specific laser conditions, with implications for heteroatomic systems.

Contribution

It introduces a new ultrafast ICD mechanism in multiply excited clusters and analyzes its dominance over traditional ionization methods under resonant laser excitation.

Findings

ICD can rapidly ionize excited clusters via energy transfer.

ICD dominates over two-photon ionization in large clusters under resonant laser pulses.

A collective ICD process is also identified in heteroatomic systems.

Abstract

An ultrafast mechanism belonging to the family of interatomic Coulombic decay (ICD) phenomena is proposed. When two excited species are present, an ultrafast energy transfer can take place bringing one of them to its ground state and ionizing the other one. It is shown that if large homoatomic clusters are exposed to an ultrashort and intense laser pulse whose photon energy is in resonance with an excitation transition of the cluster constituents, the large majority of ions will be produced by this ICD mechanism rather than by two-photon ionization. A related collective-ICD process that is operative in heteroatomic systems is also discussed.