DocumentCode :
938977
Title :
Quantum-Dot Sources for Single Photons and Entangled Photon Pairs
Author :
Young, Robert J. ; Ellis, David J P ; Stevenson, R. Mark ; Bennett, Anthony J. ; Atkinson, Paola ; Cooper, Ken ; Ritchie, David A. ; Shields, Andrew J.
Author_Institution :
Toshiba Res. Eur. Ltd., Cambridge
Volume :
95
Issue :
9
fYear :
2007
Firstpage :
1805
Lastpage :
1814
Abstract :
Quantum dots show excellent promise as triggered sources of both single and polarization entangled photons for quantum information applications. Our recent progress developing nonclassical light sources with single quantum dots is presented in this paper. Following radiative emission of an exciton confined in a quantum dot, there is a finite delay before re-excitation can occur; this results in an anti-bunching of the photons emitted providing a source of single photons. Excitation of a quantum dot with two electrons and two holes leads to the emission of a pair of photons; we show here that, provided the spin splitting of the intermediate exciton state in the decay is erased, the photon pair is emitted in an entangled polarization state. The fidelity of this entangled state is shown to exceed 70%. Using quantum dots to generate quantum light allows contacts for electrical injection to be integrated into a compact and robust device. A cavity may also be integrated into the semiconductor structure to enhance the photon collection efficiency and control the recombination dynamics. We detail a process to form a submicrometer current aperture within an electrical device, allowing individual quantum dots to be addressed electrically in devices.
Keywords :
light sources; photon antibunching; quantum entanglement; semiconductor devices; semiconductor quantum dots; electrical injection; intermediate exciton state; nonclassical light sources; photon antibunching; photon collection efficiency; polarization entangled photon pairs; quantum-dot sources; radiative emission; recombination dynamics; semiconductor structure; single photon source; spin splitting; submicrometer current aperture; Charge carrier processes; Contacts; Delay; Electron emission; Excitons; Light sources; Optical polarization; Potential well; Quantum dots; Quantum entanglement; Entangle photons; photoluminescence; quantum dots; quantum information; single photons;
fLanguage :
English
Journal_Title :
Proceedings of the IEEE
Publisher :
ieee
ISSN :
0018-9219
Type :
jour
DOI :
10.1109/JPROC.2007.900966
Filename :
4357938
Link To Document :
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