  Most of the time, electronic excitations in mesoscopic conductors are well
described, around equilibrium, by non-interacting Landau quasi-particles. This
allows a good understanding of the transport properties in the linear regime.
However, the role of interaction in the non-equilibrium properties beyond this
regime has still to be established. A paradigmatic example is the Kondo many
body state, which can be realized in a carbon nanotube (CNT) quantum dot for
temperatures below the Kondo temperature $T_K$. As CNT possess spin and orbital
quantum numbers, it is possible to investigate the twofold degenerate SU(2)
Kondo effect as well as the four fold degenerate SU(4) state by tuning the
degeneracies and filling factor. This article aims at providing a comprehensive
review on our recent works on the Kondo correlations probed by quantum noise
measurement both at low and high frequencies and demonstrate how current noise
measurements yield new insight on interaction effects and dynamics of a Kondo
correlated state.
