Shot Noise in SU(N) Quantum Dot Kondo Effects

Abstract

We study shot noise in the current of quantum dots whose low-energy behaviour corresponds to an SU(N) Kondo model, focusing on the case N=4 relevant to carbon nanotube dots. For general N, two-particle Fermi liquid interactions have two distinct effects: they can enhance the noise via back-scattering processes with an N-dependent effective charge, and can also modify the coherent partition noise already present without interactions. For N=4, in contrast to the SU(2) case, interactions enhance shot noise solely through an enhancement of partition noise. This leads to a non-trivial prediction for experiment.