Fig. 4

Photoexcitation (PE) dynamics of the In–He₄₀₀₀ system simulated with TDDFT. a Bubble radius as a function of time delay Δt, determined as the position of the corresponding He distribution at which the density has dropped to 50% of the bulk value. Times for which the calculated He density is shown in Fig. 1b are indicated. b Interaction energy \(E_{{\rm{He}}_{\rm{N}}{-{\rm{In}}^{\ast}}}\) of the 5s²6s excited state (cyan curve) and interaction energy \(E_{{{\rm{He}}_{\rm{N}}} - {{\rm{In}}^{{+}}}}\) of the 5s² ionic state (red curve). Additionally, the kinetic energy of the He atoms, E_kin,He, is plotted as dashed line. c Simulated PE peak shift induced by the He environment (orange line), obtained as \(E_{{\rm{He}}_{\rm{N}} {-{\rm{In}}^{\ast}}}\) − \(E_{{{\rm{He}}_{\rm{N}}} - {{\rm{In}}^{{ + }}}}\) (indicated by the shaded area in b), which is also shown in Fig. 2a. For comparison to the measured shift of the PE peak position over time, the recorded electron spectra at all time delays (c.f., Fig. 2b) are fitted with Gaussian functions and the line positions are indicated here by blue dots