The interaction of excited atoms and few-cycle laser pulses

TL;DR

This paper reports the first experimental observation of neon ionization in a metastable state using strong, few-cycle laser pulses, comparing results with theoretical models and revealing spin-dependent ionization rates.

Contribution

It presents the first observation of neon metastable ionization with few-cycle pulses and analyzes spin-dependent effects using advanced theoretical frameworks.

Findings

TDSE matches experimental data better than ADK theory

Ionization rate depends on atomic spin state

Physically transparent interpretation of spin dependence

Abstract

This work describes the first observations of the ionisation of neon in a metastable atomic state utilising a strong-field, few-cycle light pulse. We compare the observations to theoretical predictions based on the Ammosov-Delone-Krainov (ADK) theory and a solution to the time-dependent Schrodinger equation (TDSE). The TDSE provides better agreement with the experimental data than the ADK theory. We optically pump the target atomic species and demonstrate that the ionisation rate depends on the spin state of the target atoms and provide physically transparent interpretation of such a spin dependence in the frameworks of the spin-polarised Hartree-Fock and random-phase approximations.