Edge-state Blockade of Transport in Quantum Dot Arrays

TL;DR

This paper introduces a transport blockade mechanism in quantum dot arrays based on Coulomb interactions and topological edge states, revealing new insights into electron transport and noise characteristics.

Contribution

It demonstrates a novel edge-state blockade in quantum dot arrays linked to topological phase transitions, supported by analytical and numerical analysis.

Findings

Edge states cause a crossover in shot noise from bunching to Poissonian behavior.

Analytical Fano factor expressions match numerical quantum master equation results.

Transport blockade is driven by topological edge states and Coulomb interactions.

Abstract

We propose a transport blockade mechanism in quantum dot arrays and conducting molecules based on an interplay of Coulomb repulsion and the formation of edge states. As a model we employ a dimer chain that exhibits a topological phase transition. The connection to a strongly biased electron source and drain enables transport. We show that the related emergence of edge states is manifest in the shot noise properties as it is accompanied by a crossover from bunched electron transport to a Poissonian process. For both regions we develop a scenario that can be captured by a rate equation. The resulting analytical expressions for the Fano factor agree well with the numerical solution of a full quantum master equation.