Distortion and preservation of Giant resonances in Endohedral Atoms A@C60
M. Ya. Amusia*+, A. S. Baltenkov∇, L. V. Chernysheva+
*A.F. Ioffe Physical-Technical Institute, 194021 St.Petersburg, Russia
+Racah Institute of Physics, Hebrew University, 91904 Jerusalem, Israel
∇Arifov's Institute of Electronics, Akademgorodok, 700125 Tashkent, Uzbekistan
PACS: 31.25.-v, 32.80.-t
Abstract
It is demonstrated in this Letter that the effect of the fullerene
shell upon atomic Giant resonance decisively depends upon energy of
photoelectrons, by which the resonance decay. According to the earlier
prediction, the Giant resonance in Xe is strongly modified in the endohedral
Xe@C60 being transformed from a single broad and powerful maximum in Xe
into four quite narrow, but with almost the same total oscillator strength.
On the contrary, here the 4d Giant resonances in ions Ce3+ (the
electronic structure that Ce has, when stuffed into fullerene), in Ce4+,
and Eu are considered. In none of them the 4d Giant resonance in
endohedrals is affected essentially. This is because the decay of the Giant
resonances in these endohedrals proceeds by emission of fast photoelectrons
that are almost unaffected by the C60 shell. The results obtained give
at least qualitative explanation to the fact that relatively recent
observation of 4d Giant resonance in Ce@C82+, where the Giant
resonance was observed as a maximum without noticeable structure.