Giant dipole resonance in small metal clusters

The problem of giant dipole resonance in small metal clusters is considered. By using the finite Fermi system theory the description of the photoabsorption cross section is given. The effect of spillout of valence electrons is disregarded. It is shown that there exist two types of valence electron vibrations: giant dipole resonance and surface plasmons. The energies of the giant dipole and the plasmon resonances are calculated. The values of the maximum cross section for the two types of resonances are estimated. A comparison of theoretical results with experimental data is also given.