arXiv subjects

F. Bassani

Publications and source records attributed to F. Bassani.

3 recordsLinked to original sources

arXiv2017

Toward III-V/Si co-integration by controlling biatomic steps on hydrogenated Si(001)

The integration of III-V on silicon is still a hot topic as it will open up a way to co-integrate Si CMOS logic with photonic vices. To reach this aim, several hurdles should be solved, and more particularly the generation of antiphase boundaries (APBs) at the III-V/Si(001) interface. Density functional theory (DFT) has been used to demonstrate the existence of a double-layer steps on nominal Si(001) which is formed during annealing under proper hydrogen chemical potential. This phenomenon could be explained by the formation of dimer vacancy lines which could be responsible for the preferential and selective etching of one type of step leading to the double step surface creation. To check this hypothesis, different experiments have been carried in an industrial 300 mm MOCVD where the total pressure during the anneal step of Si(001) surface has been varied. Under optimized conditions, an APBs-free GaAs layer was grown on a nominal Si(001) surface paving the way for III-V integration on silicon industrial platform.

cond-mat.mtrl-sci↗

arXiv2001

Slow group velocity and Cherenkov radiation

We theoretically study the effect of ultraslow group velocities on the emission of Vavilov-Cherenkov radiation in a coherently driven medium. We show that in this case the aperture of the group cone on which the intensity of the radiation peaks is much smaller than that of the usual wave cone associated with the Cherenkov coherence condition. We show that such a singular behaviour may be observed in a coherently driven ultracold atomic gas.

quant-ph↗

arXiv1998

General Properties of Optical Harmonic Generation from a simple Oscillator Model

The nonlinear oscillator model allows a basic understanding of all nonlinear processes and can be adopted to analyse optical vibrational modes and electronic transition in molecules and crystals, in order to derive general properties of harmonic generation to all orders. In particular, we obtain Kramers Kroenig relations and sum rules referred to all momenta of the susceptibility, and Miller's empirical rules to all orders. Since the above properties only depend on time causality and not on the specific microscopic model, they can be adopted for the quantum mechanical description, sustituting in the classical expression the derivatives of the potential with their expectation values.

physics.optics↗