Non-Gaussian distribution of nearest-neighbour Coulomb peak spacings in metallic single electron transistors

TL;DR

This paper investigates the distribution of Coulomb peak spacings in metallic single electron transistors, revealing a non-Gaussian pattern with a tail towards smaller spacings, likely caused by impurity effects.

Contribution

It demonstrates that Coulomb peak spacings are non-Gaussian and links this to impurity-induced charge rearrangements, offering insights into quantum dot behavior.

Findings

Distribution is non-Gaussian with a tail to smaller spacings

Impurity-specific charge rearrangements influence peak spacings

Explains absence of Wigner-Dyson distribution in quantum dots

Abstract

The distribution of nearest-neighbour spacings of Coulomb blockade oscillation peaks in normal conducting aluminum single electron transistors is found to be non-Gaussian. A pronounced tail to reduced spacings is observed, which we attribute to impurity-specific parametric charge rearrangements close to the transistor. Our observation may explain the absence of a Wigner-Dyson distribution in the experimental nearest-neighbour spacing distributions in semiconductor quantum dots.