Eur. Phys. J. B 82, 29-35 (2011)
https://doi.org/10.1140/epjb/e2011-20258-y

Controlled cavity-assisted generation of single and entangled photons in semiconductor quantum dots

Institut für Physik, Karl-Franzens-Universität Graz, Universitätsplatz 5, 8010 Graz, Austria

Corresponding author: ^a ulrich.hohenester@uni-graz.at

Received: 31 March 2011
Revised: 5 May 2011
Published online: 21 June 2011

Abstract

We propose a scheme, based on a single semiconductor quantum dot inside a microcavity, for the creation of single and entangled photons with controllable waveform. A lateral electric field allows to charge the quantum dot with a single electron, and breaks the usual optical selection rules. Our scheme utilizes cavity-assisted stimulated Raman adiabatic passage (STIRAP) in order to promote the surplus electron from the ground to the excited state, via excitation of a pump pulse and optical coupling to the charged exciton. This transfer is accompanied by a synchronized emission of a single-photon wavepacket, whose waveform can be controlled by the pump pulse. We investigate the influence of phonon scatterings, and show that they allow to reset the single-photon source. Finally, we propose a slight variant of our scheme which would allow for the creation of entangled multi-photon states. All our simulations are performed with realistic quantum dot and cavity parameters, which allows us to argue that our scheme can be implemented with state-of-the-art quantum dots and microcavities.