Resonant charging of Xe clusters in helium nanodroplets under intense laser fields

We theoretically investigate the impact of multiple plasmon resonances on the charging of Xe clusters embedded in He nanodroplets under intense pump-probe laser excitation (τ = 25 fs, I ₀ = 2.5 × 10¹⁴   W/cm², λ = 800 nm). Our molecular dynamics simulations on Xe₃₀₉He_10 000 and comparison to results for free Xe₃₀₉ give clear evidence for selective resonance heating in the He shell and the Xe cluster, but no corresponding double hump feature in the final Xe charge spectra is found. Though the presence of the He shell substantially increases the maximum charge states, the pump-probe dynamics of the Xe spectra from the embedded system is similar to that of the free species. In strong contrast to that, the predicted electron spectra do show well-separated and pronounced features from highly efficient plasmon assisted electron acceleration for both resonances in the embedded clusters. A detailed analysis of the underlying ionization and recombination dynamics is presented and explains the apparent disaccord between the resonance features in the ion and electron spectra.