%0 Journal Article
%T Electric-field-induced coherent coupling of the exciton states in a single quantum dot
%A A. J. Bennett
%A M. A. Pooley
%A R. M. Stevenson
%A M. B. Ward
%A R. B. Patel
%A A. Boyer de la Giroday
%A N. Sk£żld
%A I. Farrer
%A C. A. Nicoll
%A D. A. Ritchie
%A A. J. Shields
%J Physics
%D 2012
%I arXiv
%R 10.1038/nphys1780
%X The signature of coherent coupling between two quantum states is an anticrossing in their energies as one is swept through the other. In single semiconductor quantum dots containing an electron-hole pair the eigenstates form a two-level system that can be used to demonstrate quantum effects in the solid state, but in all previous work these states were independent. Here we describe a technique to control the energetic splitting of these states using a vertical electric field, facilitating the observation of coherent coupling between them. Near the minimum splitting the eigenstates rotate in the plane of the sample, being orientated at 45{\deg} when the splitting is smallest. Using this system we show direct control over the exciton states in one quantum dot, leading to the generation of entangled photon pairs.
%U http://arxiv.org/abs/1203.5909v1