Positioning plasmonic nanostructures on single quantum emitters

Abstract

AbstractThe controlled positioning and fabrication of nanostructures on single quantum emitters allows tuning and engineering their properties. Here, we demonstrate two methods to modify the light emission properties of single semiconductor quantum dots using plasmonic nanostructures. First, we have used atomic force microscopy (AFM) based nanomanipulation to position plasmon resonant gold nanoparticles on single near‐surface GaAs quantum dots. The particles act as optical antennas significantly enhancing the photoluminescence signal. The increase in luminescence is shown to originate from an increased excitation rate of the emitter. We have also developed a method to fabricate nanostructures aligned to near‐surface semiconductor quantum dots using electron beam lithography (EBL). The accuracy of the alignment procedure achieved in this work is better than 30 nm. The flexibility of our approach allows single semiconductor quantum dots to be coupled to complex device structures in order to obtain new functionalities. As a first example we show how excitons in quantum dots can be coupled to plasmonic waveguides. Our results pave the way for realizing integrated nanoscale optical circuits for quantum optics research and applications.