Interdot Coulomb repulsion effect on the charge transport of parallel double single electron transistors

TL;DR

This paper investigates how interdot Coulomb repulsion influences charge transport in parallel double single electron transistors, revealing the creation of new resonant levels and negative differential conductance effects.

Contribution

It introduces a detailed analysis of Coulomb interactions in double SETs using the Anderson model and nonequilibrium Green's functions, highlighting effects overlooked in previous studies.

Findings

Interdot Coulomb repulsion creates new resonant levels.

Negative differential conductance observed due to Coulomb effects.

Coulomb interaction dominates over electron hopping in these systems.

Abstract

The charge transport behaviors of parallel double single electron transistors (SETs) are investigated by the Anderson model with two impurity levels. The nonequilibrium Keldysh Green's technique is used to calculate the current-voltage characteristics of system. For SETs implemented by quantum dots (QDs) embedded into a thin $SiO_2$ layer, the interdot Coulomb repulsion is more important than the interdot electron hopping as a result of high potential barrier height between QDs and $SiO_2$. We found that the interdot Coulomb repulsion not onlyleads to new resonant levels, but also creates negative differential conductances.