Coulomb blockade conductance peak fluctuations in quantum dots and the independent particle model

TL;DR

This paper investigates how temperature, classical dynamics, and shape deformations influence Coulomb blockade conductance peaks in quantum dots, comparing experimental data with theoretical models including chaotic and integrable potentials.

Contribution

It provides a comprehensive numerical analysis of conductance fluctuations in quantum dots using the independent particle model across different potential types and temperature regimes.

Findings

Peak height distribution matches experiments at low temperatures.

Peak bunching is reproduced under specific conditions.

Independent particle model explains long-range correlations but not short-range ones.

Abstract

We study the combined effect of finite temperature, underlying classical dynamics, and deformations on the statistical properties of Coulomb blockade conductance peaks in quantum dots. These effects are considered in the context of the single-particle plus constant-interaction theory of the Coulomb blockade. We present numerical studies of two chaotic models, representative of different mean-field potentials: a parametric random Hamiltonian and the smooth stadium. In addition, we study conductance fluctuations for different integrable confining potentials. For temperatures smaller than the mean level spacing, our results indicate that the peak height distribution is nearly always in good agreement with the available experimental data, irrespective of the confining potential (integrable or chaotic). We find that the peak bunching effect seen in the experiments is reproduced in the theoretical models under certain special conditions. Although the independent particle model fails, in general, to explain quantitatively the short-range part of the peak height correlations observed experimentally, we argue that it allows for an understanding of the long-range part.