Engineering electron and hole tunneling with asymmetric InAs quantum dot molecules

TL;DR

This paper demonstrates how to engineer and control electron and hole tunneling in asymmetric InAs quantum dot molecules by intentionally introducing asymmetry, enabling precise design of quantum nanostructures.

Contribution

It introduces a method to intentionally create asymmetry in InAs quantum dot molecules, allowing selective tunneling control and systematic investigation of tunneling energies.

Findings

Successful growth of asymmetric InAs/GaAs quantum dot pairs.

Tunneling energies vary systematically with barrier thickness.

Provides a framework for designing complex quantum dot structures.

Abstract

Most self-assembled quantum dot molecules are intrinsically asymmetric with inequivalent dots resulting from imperfect control of crystal growth. We have grown vertically-aligned pairs of InAs/GaAs quantum dots by molecular beam epitaxy, introducing intentional asymmetry that limits the influence of intrinsic growth fluctuations and allows selective tunneling of electrons or holes. We present a systemic investigation of tunneling energies over a wide range of interdot barrier thickness. The concepts discussed here provide an important tool for the systematic design and characterization of more complicated quantum dot nanostructures.