Dynamical effects of confinement on atomic valence photoionization in $\text{Mg}@{\text{C}}_{60}$

We predict a huge dynamical boost from collective electron motion on the valence $3\mathit{s}$ photoionization of Mg in the $\text{Mg}@{\text{C}}_{60}$ molecule. Calculations have been performed in a framework of time-dependent local density approximation that includes coupling between dipole-allowed final state channels. Our results qualitatively agree with the recent predictions of a semiclassical model, however, significantly differing in magnitude. In particular, a strong dependence on the nature of the caged atom is found which is at odds with the prediction of the semiclassical result.

Figure 1

(Color online) Bottom panel: The average radial LDA ground state potential. All ${\text{C}}_{60}$ single-electron levels and the valence $3\mathit{s}$ levels of the confined Mg are shown. Top panel, free and confined Mg $3\mathit{s}$ radial wave functions. The radial wave functions of some pristine ${\text{C}}_{60}$ levels are also displayed.

Figure 2

(Color online) Free and confined Mg $3\mathit{s}$ photoionization cross sections calculated using the correlated TDLDA method, along with the total photoionization cross section of pristine ${\text{C}}_{60}$ calculated in the same manner. Also shown is an earlier molecular calculation at the uncorrelated LDA level [23].

Figure 3

(Color online) Ratio of the $3s$ photionization cross sections of $\text{Mg}@{\text{C}}_{60}$ and free Mg, the corresponding ratio for Ar $3p$ [13] and the predictions of the semiclassical model [11, 12] using input parameters from the present calculation for consistency.