Present proposals for the realisation of entangled photon pair sources using the radiative decay of the biexciton in semiconductor quantum dots are limited by the need to enforce degeneracy of the two intermediate, single exciton states. We show how this requirement is lifted if the biexciton binding energy can be tuned to zero and we demonstrate this unbinding of the biexciton in a single, pre-positioned InAs quantum dot subject to a lateral electric field. Full Configuration-Interaction calculations are presented that reveal how the biexciton is unbound through manipulation of the electron-hole Coulomb interaction and the consequent introduction of Hidden Symmetry.
@article{arxiv.0706.1075,
title = {Voltage Induced Hidden Symmetry and Photon Entanglement Generation in a Single, Site-Selected Quantum Dot},
author = {Michael E. Reimer and Marek Korkusinski and Jacques Lefebvre and Jean Lapointe and Philip J. Poole and Geof C. Aers and Dan Dalacu and W. Ross McKinnon and Simon Frederick and Pawel Hawrylak and Robin L. Williams},
journal= {arXiv preprint arXiv:0706.1075},
year = {2007}
}
Comments
4 pages, 4 figures submitted to Physical Review Letters