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Accueil du site > Séminaires > Séminaires 2014 > Ultra-fast carrier relaxation in bulk silicon following the photo-excitation with a short and polarized laser pulse

Mardi 25 novembre 2014-14:00

Ultra-fast carrier relaxation in bulk silicon following the photo-excitation with a short and polarized laser pulse

Andrea Marini (Istituto di Struttura della Materia, CNR, Rome)

par Gabriel LeMarié - 25 novembre 2014

A novel approach based on the merging of the out-of-equilibrium Green’s function method with the Density-Functional-Theory is used to describe the ultra-fast carriers relaxation in Silicon. The results are compared with recent two photon photo-emission measurements showing that the state-of-the-art interpretation of the carrier relaxation in terms of L->X inter-valley scattering is not correct. The ultra-fast dynamics measured experimentally is, instead, due to the scattering between degenerate L states that is activated by the non symmetric population of the conduction bands induced by the laser field. This ultra-fast relaxation is, then, entirely due to the specific experimental setup and it can be interpreted by introducing a novel definition of the quasi-particle lifetimes in an out-of-equilibrium context.

Post-scriptum :

contact : P. Romaniello