Bright single-photon sources in bottom-up tailored nanowires

TL;DR

This paper demonstrates a bottom-up growth method for perfectly positioning single quantum dots in nanowire waveguides, achieving high light extraction efficiency and significantly enhancing single-photon flux for quantum communication.

Contribution

It introduces a novel bottom-up fabrication technique for aligned quantum dots in nanowires, overcoming limitations of top-down methods and improving photon extraction efficiency.

Findings

Achieved 42% light extraction efficiency.

Demonstrated 24-fold increase in single photon flux.

Enabled potential for long-distance quantum information transfer.

Abstract

The ability to achieve near-unity light extraction efficiency is necessary for a truly deterministic single photon source. The most promising method to reach such high efficiencies is based on embedding single photon emitters in tapered photonic waveguides defined by top-down etching techniques. However, light extraction efficiencies in current top-down approaches are limited by fabrication imperfections and etching induced defects. The efficiency is further tempered by randomly positioned off-axis quantum emitters. Here, we present perfectly positioned single quantum dots on the axis of a tailored nanowire waveguide using bottom-up growth. In comparison to quantum dots in nanowires without waveguide, we demonstrate a 24-fold enhancement in the single photon flux, corresponding to a light extraction efficiency of 42 %. Such high efficiencies in one-dimensional nanowires are promising to transfer quantum information over large distances between remote stationary qubits using flying qubits within the same nanowire p-n junction.