Ultrafast coherent spectroscopy of a single self‐assembled quantum dot

Abstract

AbstractThe controlled interaction of several quantum dots (QDs) mediated by plasmonic or photonic nanostructures promises interesting new functionality in the fields of quantum computing and telecommunication. Ultrafast laser pulses can be used to write and read out the state of the QD. We review ultrafast coherent spectroscopy of single QDs. The focus of this article is on the technique of transient reflection spectroscopy which can be applied to a broad range of samples and devices. It only requires optical access to a single quantum system next to a reflecting surface. We demonstrate the versatility of our approach by presenting several quantum optical studies such as Rabi oscillations, perturbed free induction decay, and quantum beats from an entangled excitonic state in weakly absorbing GaAs QDs. We expect this experimental method to make coherent experiments possible in elaborate devices where quantum emitters are interacting with a complex environment such as plasmonic waveguides or antennas.