Thin-film effects on the surface stopping power of a free electron gas

The electronic properties of thin films present quantum-size effects, which are a consequence of the finite size of the system. Here we focus on the investigation of these effects on the electronic energy loss of charged particles moving parallel with thin metallic films. The energy loss is calculated, within linear-response theory, from the knowledge of the density-response function of the inhomogeneous electron system, which we evaluate either in the random-phase approximation or with the use of an adiabatic and local exchange-correlation kernel.