Low-frequency absorption of electro-magnetic radiation in thin metallic films

We study the absorption of low-frequency radiation in thin metallic films w ith ballistic electron dynamics. Incorporating screening effects, we calcul ate an approximation to the effective potential inside the film using a qua si-classical approach. This approach combined with Fermi's golden rule is u sed to derive an analytical formula for the absorption coefficient valid fo r frequencies much smaller than the plasma frequency, and high electron den sities. (C) 2001 Elsevier Science B.V. All rights reserved.