Interatomic Coulombic decay cascades in multiply excited neon clusters

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Laser-Matter Interactions

Background:

• Matter ionization in high-intensity laser fields typically occurs via multiphoton absorption.
• Resonant excitation enhances ionization through indirect pathways like interatomic Coulombic decay (ICD).
• ICD involves de-excitation of one species to ionize another excited species.

Purpose of the Study:

• To investigate ionization mechanisms in multiply excited systems under resonant laser excitation.
• To identify and characterize novel decay pathways beyond established ICD processes.
• To explore the potential for enhanced ion production in weakly-bound systems.

Main Methods:

• Theoretical modeling of atomic and molecular systems subjected to high-intensity resonant laser fields.
• Simulation of electron dynamics and energy transfer processes.
• Analysis of decay cascades initiated by resonant excitation to higher Rydberg states.

Main Results:

• Identification of a new ionization mechanism: intra-Rydberg interatomic Coulombic decay (ICD).
• Demonstration that de-excitation to a Rydberg state can trigger electron emission from a neighboring Rydberg atom.
• Observation of cascading intra-Rydberg ICD processes leading to multiply charged ions.

Conclusions:

• Intra-Rydberg ICD represents a significant, previously unrecognized ionization pathway.
• Cascading intra-Rydberg ICD processes can substantially amplify ion yields in resonant laser-matter interactions.
• This phenomenon is anticipated to be widespread in weakly-bound systems under resonant high-intensity laser irradiation.