Lifetimes and quantum efficiencies of quantum dots deterministically positioned in photonic-crystal waveguides

TL;DR

This paper demonstrates the deterministic positioning of quantum dots within photonic-crystal waveguides to control their emission properties, enabling advancements in quantum photonic circuits.

Contribution

It introduces a spectroscopy-based method for precise placement of quantum dots in nanophotonic structures, enhancing emission control capabilities.

Findings

Quantum dot emission can be suppressed or enhanced depending on positioning.

Positioning quantum dots enables control over emission direction and decay rates.

Photonic-crystal waveguides can be used to manipulate single-photon emission.

Abstract

Interfacing single emitters and photonic nanostructures enables modifying their emission properties, such as enhancing individual decay rates or controlling the emission direction. To achieve full control, the single emitter must be positioned in the nanostructures deterministically. Here, we use spectroscopy to gain spectral and spatial information about individual quantum dots in order to position each emitter in a pre-determined location in a unit cell of a photonic-crystal waveguide. Depending on the spatial and spectral positioning within the structured nanophotonic mode, we observe that the quantum dot emission can either be suppressed or enhanced. These results demonstrate the capacity of photonic-crystal waveguides to control the emission of single photons and that the ability to position quantum dots will be crucial to the creation of complex multi-emitter quantum photonic circuits.