Coupling of self-assembled quantum dots to plasmonic nanoantennas

Abstract

In the radio frequency range antennas make it possible to direct the emission of an oscillator in a very controlled way towards the receiver. In the optical frequency range, particle plasmons, i.e., collective resonant oscillations of the electrons in a metal nanoparticle, are a good candidate for antennas. Albeit, simple downscaling of concepts from radio waves is not possible, as, for example, losses in metals are much higher in the optical range. In this project, our ‘oscillator’ is a single GaAs semiconductor quantum dot which shows very stable photoemission. The ‘antenna’ is a metal nanowire in close proximity. The nanoantenna modifies the radiative emission rate k rad of the quantum dot, but also absorbs power, i.e., modifies the non-radiative rate k NR . Both can be deduced by their influence on the luminescence intensity I and lifetime τ of a single quantum dot.