Transport properties of two laterally coupled vertical quantum dots in series with tunable inter-dot coupling

TL;DR

This paper investigates the electronic transport properties of a double vertical quantum dot system with tunable inter-dot coupling, revealing effects like current rectification and Pauli spin blockade under various coupling regimes.

Contribution

It introduces a method to control lateral coupling in double quantum dots in-situ and studies the resulting transport phenomena in different coupling regimes.

Findings

Current rectification observed due to Pauli spin blockade.

Tunable inter-dot coupling achieved via center gate voltage.

Charging diagrams characterized for different source-drain voltages.

Abstract

We describe the electronic properties of a double dot for which the lateral coupling between the two vertical dots can be controlled in-situ with a center gate voltage (Vc) and the current flows through the two dots in series. When Vc is large and positive, the two dots merge. As Vc is made less positive, two dots are formed whose coupling is reduced. We measure charging diagrams for positive and negative source-drain voltages in the weak coupling regime and observe current rectification due to the Pauli spin blockade when the hyperfine interaction between the electrons and the nuclei is suppressed.