High-order current correlation functions in Kondo systems

Abstract

We examine the statistics of current fluctuations in a junction with a quantum dot described by Kondo Hamiltonian. With the help of modified Keldish technique we calculate the third current cumulant. As a function of ratio $v=eV/T_{K}$ the 3rd cumulant was obtained for three different regimes: Fermi liquid regime (v<1), crossover interval ($v\geq1$) and RG limit (v>>1). Unlike the case of noninteracting dot, 3rd cumulant shows strong non-linear voltage dependence. Only in the asymptotical limit of large voltages the linear dependence on $V$ is recovered.