Facile Self-Assembly of Quantum Plasmonic Circuit Components

TL;DR

This paper presents a simple, cost-effective chemical self-assembly method for creating quantum plasmonic circuits by attaching nanodiamonds with NV centers to silver nanowires, enabling efficient plasmonic coupling.

Contribution

It introduces a novel self-assembly technique that simplifies the fabrication of quantum plasmonic components, avoiding complex and costly traditional methods.

Findings

Nanodiamond and nanowire coupling achieved with optimized AA concentration.

Fluorescence lifetime reduced by over two-fold, indicating strong plasmonic coupling.

Enhanced fluorescence intensity observed in coupled structures.

Abstract

Efficient coupling between solid state quantum emitters and plasmonic waveguides is important for the realization of integrated circuits for quantum information, communication and sensing. However, realization of plasmonic circuits is still scarce, particularly due to challenges associated with accurate positioning of quantum emitters near plasmonic resonators. Current pathways for the construction of plasmonic circuits involve cumbersome and costly methods such as scanning atomic force microscopy or mechanical manipulation, where individual elements are physically relocated using the scanning tip. Here, we introduce a simple, fast and cost effective chemical self-assembly method for the attachment of two primary components of a practical plasmonic circuit: a single photon emitter and a waveguide. Our method enables coupling of nanodiamonds with a single quantum emitter (the nitrogen-vacancy (NV) center) onto the terminal of a silver nanowire, by simply varying the concentration of ascorbic acid (AA) in a reaction solution. The AA concentration is used to control the extent of agglomeration, and can be optimised so as to cause preferential, selective activation of the tips of the nanowires. The nanowire-nanodiamond structures show efficient plasmonic coupling of fluorescence emission from single NV centers into surface plasmon polariton (SPP) modes, evidenced by a more than two-fold reduction in fluorescence lifetime and an increase in fluorescence intensity.