Intermediate Field Coupling of Single Epitaxial Quantum Dots to Plasmonic Waveguides

Title data

Seidel, Michael ; Yang, Yuhui ; Schumacher, Thorsten ; Huo, Yongheng ; Covre da Silva, Saimon Filipe ; Rodt, Sven ; Rastelli, Armando ; Reitzenstein, Stephan ; Lippitz, Markus:
Intermediate Field Coupling of Single Epitaxial Quantum Dots to Plasmonic Waveguides.
In: Nano Letters. Vol. 23 (2023) Issue 22 . - pp. 10532-10537.
ISSN 1530-6992
DOI: https://doi.org/10.1021/acs.nanolett.3c03442

Project information

Abstract in another language

Key requirements for quantum plasmonic nanocircuits are reliable single-photon sources, high coupling efficiency to the plasmonic structures, and low propagation losses. Self-assembled epitaxially grown GaAs quantum dots are close to ideal as stable, bright, and narrowband single-photon emitters. Likewise, wet-chemically grown monocrystalline silver nanowires are among the best plasmonic waveguides. However, large propagation losses of surface plasmons on the high-index GaAs substrate prevent their direct combination. Here, we show by experiment and simulation that the best overall performance of the quantum plasmonic nanocircuit based on these building blocks is achieved in the intermediate field regime with an additional spacer layer between the quantum dot and the plasmonic waveguide. High-resolution cathodoluminescence measurements allow a precise determination of the coupling distance and support a simple analytical model to explain the overall performance. The coupling efficiency is increased up to four times by standing wave interference near the end of the waveguide.