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Disorder, noise and interaction play a crucial role in the transport properties of real systems, but they are typically hard to control and study, both theoretically and experimentally, especially in the quantum case. Here, we explore a paradigmatic problem, the diffusion of a wavepacket, by employing ultra-cold atoms in a quasi-periodic lattice with controlled noise and tunable interaction. The presence of quasi-disorder leads to Anderson localization, while both interaction and noise tend to suppress localization and restore transport, although with completely different mechanisms. When only noise or interaction is present, we observe a diffusion dynamics that can be explained by existing microscopic models. When noise and interaction are combined, we observe instead a complex anomalous diffusion. By combining experimental measurements with numerical simulations, we show that such anomalous behavior can be modeled with a generalized diffusion equation in which the noise- and interaction-induced diffusions enter in an additive manner. Our study reveals also a more complex interplay between the two diffusion mechanisms in the regimes of strong interaction or narrowband noise. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) films are grown on Si(111) using as a precursor fullerene seeded in helium supersonic beams. The regime of energy and flux distributions, achievable by changing the beam parameters, is well suited to synthesizing SiC films under well ordered conditions, because of better control of the synthesis process and of the C[sub 60] dissociative absorption. This is confirmed by the first experimental results and by morphological and structural characterization of the films produced. Further developments are briefly discussed. [ABSTRACT FROM AUTHOR]