Effect of dephasing on mesoscopic conductance fluctuations in quantum dots with single channel leads

TL;DR

This paper investigates how dephasing affects conductance fluctuations in disordered quantum dots with single channel leads, revealing a transition from non-Gaussian to mainly Gaussian distributions under strong dephasing conditions.

Contribution

It introduces a perturbative diagrammatic approach to describe dephasing effects, accounting for level broadening contributions while conserving particle number, and characterizes the resulting conductance distribution.

Findings

Distribution becomes mainly Gaussian with non-universal variance under strong dephasing.

Zero dephasing leads to a non-Gaussian conductance distribution.

The approach accounts for two different contributions to level broadening.

Abstract

We consider the distribution of conductance fluctuations in disordered quantum dots with single channel leads. Using a perturbative diagrammatic approach, valid for continuous level spectra, we describe dephasing due to processes within the dot by considering two different contributions to the level broadening, thus satisfying particle number conservation. Instead of a completely non-Gaussian distribution, which occurs for zero dephasing, we find for strong dephasing that the distribution is mainly Gaussian with non-universal variance and non-Gaussian tails.