• background and partition noise
• current correlations
• delta t noise
• integer quantum Hall effect
• scattering approach in chiral systems
• superconductivity

In this thesis we investigate current correlations in chiral coherent electronic scattering systems exhibiting Integer Quantum Hall Effect at spin-polarized $\nu=2$ in the presence of normal spin-mixing or Andreev processes between the edge states.
We assume to be able to inject and collect them from different contacts, as recently realized experimentally.
We also assume to be able to mix them by using finger-like scatterers placed along their path, either consisting of normal spin-mixers or superconducting material.
First, we find that current correlations generically exhibit two physically distinct contributions, which we recognize as background and excess noise.
The latter is the most relevant term since it carries the contribution of the partition noise, which is clearly absent in simple average currents' measurements.
We study then the correlations both when the scattering region is made out only of a normal spin mixer and when it is made out only of a superconductor capable of perfect crossed Andreev reflection.
We analyze noise not only as a function of the voltages applied to the contacts but also for different temperatures, characterizing the so called $\Delta T$ noise in its low and high temperature limits.
We obtain then the correlations' expressions for a sequence of two different finger-like scatterers along the edge states, underlining the differences in their behaviour due to the scatterers' order.
Finally, we investigate the signatures of the contributions due to superconductors or spin-mixers, by discussing the dependencies on the source contact voltages and temperatures and how their different contributions are mutually hindered.