EPJ D Colloquium - Quantum optics with quantum dots

Maps of the wavefunctions of the first five electronic levels in the conduction band of a single InAsP/InP quantum dot, measured by by scanning tunneling microscopy and spectroscopy

The aim of quantum information research is to harness the distinctive features of quantum physics, especially superposition and entanglement, to enhance the functionality and power of information and communication technologies. It has been a thriving interdisciplinary field of research for the last thirty years, extending from the fundamental investigation of quantum phenomena to the experimental implementation of disruptive quantum-enabled technologies.

Among quantum systems, photons constitute a natural choice for communication and metrology, and a promising route for quantum simulation and computing. These applications require ideally deterministic light sources that can deliver on-demand single photons, indistinguishable single photons or entangled photon pairs, produced at high repetition rate. For the past fifteen years, single semiconductor quantum dots, often referred to as solid-state artificial atoms, have been at the forefront of various lines of research in the field of experimental QI science, in particular related to the development of practical sources of quantum states of light.

In this EPJ D Colloquium paper, the authors review the research carried out towards tailoring the optical emission properties of single quantum dots for experimental QI applications. Following a recap of the physical principles behind the optical properties of semiconductor quantum dots, they describe the various approaches developed for efficiently producing single photons on demand. They then present the different strategies implemented for restoring photon indistinguishability as well as the different schemes developed for the production of entangled photons from single quantum dots.

At the conclusion of the Colloquium, recent progress in the field is described and the authors consider future prospects for the applications of single quantum dots in quantum information processing.

Pere Roca i Cabarrocas and Daniel Lincot
ISSN: 2105-0716 (Electronic Edition)

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