Full counting statistics for SU(N) impurity Anderson model

TL;DR

This paper investigates the full counting statistics of a multiorbital SU(N) Kondo quantum dot, revealing how electron transfer processes and orbital correlations depend on Coulomb interactions and symmetry.

Contribution

It introduces a renormalized perturbation theory approach to calculate current distributions for arbitrary Coulomb repulsion in SU(N) quantum dots.

Findings

Identifies two types of electron transfer with different charge quanta and N-dependence.

Shows exponential enhancement of cross correlations with Coulomb interaction U.

Addresses formation of orbital-singlet states through current correlations.

Abstract

We analyze the full counting statistics of a multiorbital Kondo effect in a quantum dotwith the SU(N) symmetry in the framework of the renormalized perturbation theory. The current probability distribution function is calculated for an arbitrary dot-site Coulomb repulsion $U$ in the particle-hole symmetric case. The resulting cumulant up to the leading nonlinear term of applied bias voltages indicates two types of electron transfer, respectively carrying charge $e$ and $2e$, with different $N$-dependences. The cross correlation between different orbital currents shows exponential enhancement with respect to $U$, which directly addresses formation of the orbital-singlet state.