engleski

Surface plasmon and electron-hole structures in the excitation spectra of thin films

Surface excitation spectra are calculated, including both collective and single-particle modes, and examined in detail. This is achieved by calculating the non-local dielectric function e_{; ; ; p}; ; ; (Q, z, z', w ) of the thin jellium film within the Random Phase Approximation (using Local Density Approximation wave-functions which actually takes us beyond the RPA), from which we then derive the spectral function. High precision of the calculations enables us to analyze not only the collective (surface plasmon) modes and their dependence of film thickness, but also the intraband electron-hole excitations, and for the first time oscillatory structures due to interband transitions. The spectra are then analyzed with special attention to their dependence of on the slab thickness, and the periodic peaks observed due to single-particle excitations in the spectra.

Surface palsmons; Electron-hole excitations

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