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A semiconductor source of triggered entangled photon pairs.
R M Stevenson1, R J Young, P Atkinson
1Toshiba Research Europe Limited, 260 Cambridge Science Park, Cambridge CB4 0WE, UK.
Nature
|January 13, 2006
Summary
Researchers demonstrate triggered polarization-entangled photon pairs from quantum dots by tuning exciton energy splitting to zero. This breakthrough offers a promising path toward on-demand entangled photon sources for quantum information applications.
Area of Science:
- Quantum Optics
- Solid-State Physics
- Quantum Information Science
Background:
- Entangled photon pairs are crucial for quantum information technologies like quantum key distribution.
- Quantum dots decaying from biexcitons are a proposed source of entangled photons.
- Previous experiments showed classical correlations due to exciton energy splitting.
Purpose of the Study:
- To demonstrate triggered polarization-entangled photon pair emission from single quantum dots.
- To overcome limitations of previous methods that resulted in classical correlations.
- To enable on-demand generation of entangled photons for quantum applications.
Main Methods:
- Utilizing biexciton radiative decay in single quantum dots.
- Tuning the intermediate exciton energy splitting to zero.
- Employing an in-plane magnetic field or precise control of growth conditions.
Main Results:
- Achieved triggered photon pair emission from quantum dots.
- Demonstrated emission characteristics suggestive of polarization entanglement.
- Successfully eliminated classical correlations by minimizing exciton energy splitting.
Conclusions:
- On-demand generation of polarization-entangled photon pairs from quantum dots is feasible.
- This method overcomes drawbacks of other entanglement schemes, such as multiple pair emission.
- A simple semiconductor light-emitting diode could potentially host a triggered entangled photon pair source.
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