Engineering of selective carrier injection in patterned arrays of single-quantum-dot entangled photon light-emitting diodes

TL;DR

This paper presents a scalable, semiconductor-based quantum dot array with selective carrier injection, enabling the production of entangled photon sources suitable for integrated quantum photonic circuits.

Contribution

It introduces a novel design of site-controlled quantum dot LEDs with selective injection, enhancing scalability and reproducibility for quantum information applications.

Findings

Some devices produce entangled photon pairs violating Bell's inequality

High density of light-emitting diodes achieved in non-planar structures

Compatibility with semiconductor fabrication demonstrated

Abstract

Scalability and foundry compatibility (as for example in conventional silicon based integrated computer processors) in developing quantum technologies are exceptional challenges facing current research. Here we introduce a quantum photonic technology potentially enabling large scale fabrication of semiconductor-based, site-controlled, scalable arrays of electrically driven sources of polarization-entangled photons, with the potential to encode quantum information. The design of the sources is based on quantum dots grown in micron-sized pyramidal recesses along the crystallographic direction (111)B theoretically ensuring high symmetry of the quantum dots - the condition for actual bright entangled photon emission. A selective electric injection scheme in these non-planar structures allows obtaining a high density of light-emitting diodes, with some producing entangled photon pairs also violating Bell's inequality. Compatibility with semiconductor fabrication technology, good reproducibility and control of the position make these devices attractive candidates for integrated photonic circuits for quantum information processing.