Super-Poissonian noise in a Coulomb blockade metallic quantum dot structure

TL;DR

This paper investigates shot noise in a Coulomb blockade metallic quantum dot structure, revealing conditions for super-Poissonian noise and emphasizing charge accumulation as the key factor, using a master equation approach.

Contribution

It demonstrates how charge accumulation, rather than negative differential conductance, causes super-Poissonian noise in a quantum dot system, with analysis based on the master equation.

Findings

Noise can be sub-Poissonian or super-Poissonian depending on system parameters.

Charge accumulation in the quantum dot drives super-Poissonian noise.

Super-Poissonian noise is not necessarily linked to negative differential conductance.

Abstract

The shot noise of the current through a single electron transistor (SET), coupled capacitively with an electronic box, is calculated, using the master equation approach. We show that the noise may be sub-Poissonian or strongly super-Poissonian, depending mainly on the box parameters and the gate. The study also supports the idea that not negative differential conductance, but charge accumulation in the quantum dot, responds for the super-Poissonian noise observed.