Coupling of a Single Quantum Emitter to End-to-end Aligned Silver Nanowires

We report on the observation of coupling a single nitrogen vacancy (NV) center in a nanodiamond crystal to a propagating plasmonic mode of silver nanowires. The nanocrystal is placed either near to the apex of a single silver nanowire or in the gap between two end-to-end aligned silver nanowires. We observe an enhancement of the NV-centers' decay rate in both cases as a result of the coupling to the plasmons. The devices are nano-assembled with a scanning probe technique. Through simulations, we show that end-to-end aligned silver nanowires can be used as a controllable splitter for emission from a dipole emitter.Comment: 5 pages, 4 figure

Facile Self-Assembly of Quantum Plasmonic Circuit Components

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.Comment: Published in Advanced Materials on 2 June 201