Figure 5: The time-dependent results for the negatively charged nanocluster.

(a) The dipole moment shows a much slower decay compared with the neutral Ag₅₅ (Fig. 2a). (b) The number of excited electrons ΔO_j(t). The major electron excitations are onto the 304th eigen state. The excitations onto the 301st–303rd eigen states shown in Fig. 4a do not exist. (c) The energies stored in the plasmon mode and single-particle excitations. The energy transfer from the plasmon to single-particle excitations is also much slower compared with Fig. 4b, which indicates the slow plasmon decay, because the main single-particle d to s excitation channels resonant to the plasmon are blocked in . (d) The charge density difference Δρ at time t as labelled in a, which corresponds to the local maximum or local minimum of the dipole moment. Compared with Fig. 2b, the significant charge sloshing on the surface still exists around 40 fs, which shows the plasmon is not fully decayed.