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arXiv · 1409.1706

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

Davide Sangalli·Andrea Marini
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Abstract

A novel approach based on the merging of the out--of--equilibrium Green's function method with the ab-initio, 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. We show that the 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.

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Davide Sangalli, Andrea Marini. 2014-09-05. Ultra--fast carriers relaxation in bulk silicon following photo--excitation with a short and polarized laser pulse. https://arxiv.org/abs/1409.1706

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