On the multifaceted journey for the invention of epitaxial quantum dots

TL;DR

This paper provides a historical and analytical overview of the development of epitaxial quantum dots over the past 40 years, highlighting their structures, methods, challenges, and potential applications in quantum technologies.

Contribution

It offers a comprehensive historical perspective and critical analysis of early developments, structures, and current challenges in epitaxial quantum dot research.

Findings

Diverse epitaxial structures and methods have been developed.

Despite progress, the field remains far from mature in applications.

Current challenges include material quality and device integration.

Abstract

Epitaxial semiconductor quantum dots have been, in the last 40 years or so, at the center of the research effort of a large community. The focus being on semiconductor physics and devices, in view of the broad applications and potential, e.g., for efficient temperature insensitive lasers at telecom wavelengths, or as artificial atoms for quantum information processing. Our manuscript aims at addressing, with an historical perspective, the specifics of (III-V) epitaxial quantum dot early developments (largely for light emitting) and subsequent years. We will not only highlight the variety of epitaxial structures and methods, but also, intentionally glancing a didactic approach, discuss aspects that are, in general, little acknowledged or debated in the present literature. The analyses will also naturally bring us to examine some of current challenges, in a field which, despite sensational achievements, is, remarkably, still far from being mature in its developments and applications.