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Ultrabright source of entangled photon pairs

Abstract

A source of triggered entangled photon pairs is a key component in quantum information science1; it is needed to implement functions such as linear quantum computation2, entanglement swapping3 and quantum teleportation4. Generation of polarization entangled photon pairs can be obtained through parametric conversion in nonlinear optical media5,6,7 or by making use of the radiative decay of two electron–hole pairs trapped in a semiconductor quantum dot8,9,10,11. Today, these sources operate at a very low rate, below 0.01 photon pairs per excitation pulse, which strongly limits their applications. For systems based on parametric conversion, this low rate is intrinsically due to the Poissonian statistics of the source12. Conversely, a quantum dot can emit a single pair of entangled photons with a probability near unity but suffers from a naturally very low extraction efficiency. Here we show that this drawback can be overcome by coupling an optical cavity in the form of a ‘photonic molecule’13 to a single quantum dot. Two coupled identical pillars—the photonic molecule—were etched in a semiconductor planar microcavity, using an optical lithography method14 that ensures a deterministic coupling to the biexciton and exciton energy states of a pre-selected quantum dot. The Purcell effect ensures that most entangled photon pairs are emitted into two cavity modes, while improving the indistinguishability of the two optical recombination paths15,16. A polarization entangled photon pair rate of 0.12 per excitation pulse (with a concurrence of 0.34) is collected in the first lens. Our results open the way towards the fabrication of solid state triggered sources of entangled photon pairs, with an overall (creation and collection) efficiency of 80%.

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Figure 1: Principle of photon extraction using a photonic molecule.
Figure 2: Polarization properties of modes of the photonic molecule.
Figure 3: Photon correlation measurements on molecule B.
Figure 4: Characterization of the source: entanglement and brightness.

References

  1. Bouwmeester, D., Ekert, A. K. & Zeilinger, A. The Physics of Quantum Information (Springer, 2000)

    Book  Google Scholar 

  2. Lanyon, B. P. et al. Towards quantum chemistry on a quantum computer. Nature Chem. 2, 106–111 (2010)

    ADS  CAS  Article  Google Scholar 

  3. De Riedmatten, H. et al. Long-distance entanglement swapping with photons from separated sources. Phys. Rev. A 71, 050302 (2005)

    ADS  Article  Google Scholar 

  4. Bouwmeester, D. et al. Experimental quantum teleportation. Nature 390, 575–579 (1997)

    ADS  CAS  Article  Google Scholar 

  5. Ou, Z. Y. & Mandel, L. Violation of Bell's inequality and classical probability in a two-photon correlation experiment. Phys. Rev. Lett. 61, 50–53 (1988)

    ADS  MathSciNet  CAS  Article  Google Scholar 

  6. Kwiat, P. G. et al. New high-intensity source of polarization entangled photon pairs. Phys. Rev. Lett. 75, 4337–4341 (1995)

    ADS  CAS  Article  Google Scholar 

  7. Fulconis, J., Alibart, O., Wadsworth, W. J. & Rarity, J. G. Quantum interference with photon pairs using two micro-structured fibres. N. J. Phys. 9, 276 (2007)

    Article  Google Scholar 

  8. Young, R. J. et al. Improved fidelity of triggered entangled photons from single quantum dots. N. J. Phys. 8, 29 (2006)

    Article  Google Scholar 

  9. Akopian, N. et al. Entangled photon pairs from semiconductor quantum dots. Phys. Rev. Lett. 96, 130501–130504 (2006)

    ADS  CAS  Article  Google Scholar 

  10. Hafenbrak, R. et al. Triggered polarization-entangled photon pairs from a single quantum dot up to 30 K. N. J. Phys. 9, 315 (2007)

    Article  Google Scholar 

  11. Muller, A., Fang, W., Lawall, J. & Solomon, G. S. Creating polarization-entangled photon pairs from a semiconductor quantum dot using the optical Stark effect. Phys. Rev. Lett. 103, 217402 (2009)

    ADS  Article  Google Scholar 

  12. Scarani, V., de Riedmatten, H., Marcikic, I., Zbinden, H. & Gisin, N. Four-photon correction in two-photon Bell experiments. Eur. Phys. J. D 32, 129–138 (2005)

    ADS  CAS  Article  Google Scholar 

  13. Bayer, M. et al. Optical modes in photonic molecules. Phys. Rev. Lett. 81, 2582–2585 (1998)

    ADS  CAS  Article  Google Scholar 

  14. Dousse, A. et al. Controlled light-matter coupling for a single quantum dot embedded in a pillar microcavity using far-field optical lithography. Phys. Rev. Lett. 101, 267404 (2008)

    ADS  CAS  Article  Google Scholar 

  15. Stace, T. M., Milburn, G. J. & Barnes, C. H. W. Entangled two-photon source using biexciton emission of an asymmetric quantum dot in a cavity. Phys. Rev. B 67, 085317 (2003)

    ADS  Article  Google Scholar 

  16. Larqué, M. et al. Bell inequalities and density matrix for polarization-entangled photons out of a two-photon cascade in a single quantum dot. Phys. Rev. A 77, 042118 (2008)

    ADS  Article  Google Scholar 

  17. Benson, O., Santori, C., Pelton, M. & Yamamoto, Y. Regulated and entangled photons from a single quantum dot. Phys. Rev. Lett. 84, 2513–2516 (2000)

    ADS  CAS  Article  Google Scholar 

  18. Gérard, J. M. & Gayral, B. Strong Purcell effect for InAs quantum boxes in three-dimensional solid-state microcavities. J. Lightwave Technol. 17, 2089–2095 (1999)

    ADS  Article  Google Scholar 

  19. Moreau, E. et al. Single-mode solid-state single photon source based on isolated quantum dots in pillar microcavities. Appl. Phys. Lett. 79, 2865–2867 (2001)

    ADS  CAS  Article  Google Scholar 

  20. Larqué, M., Karle, T., Robert-Philip, I. & Beveratos, A. Optimizing H1 cavities for the generation of entangled photon pairs. N. J. Phys. 11, 033022 (2009)

    Article  Google Scholar 

  21. Lee, K. H. et al. Registration of single quantum dots using cryogenic laser photolithography. Appl. Phys. Lett. 88, 193106 (2006)

    ADS  Article  Google Scholar 

  22. Ellis, D. J. P. et al. Control of fine-structure splitting of individual InAs quantum dots by rapid thermal annealing. Appl. Phys. Lett. 90, 011907 (2007)

    ADS  Article  Google Scholar 

  23. James, D. F. V., Kwiat, P. G., Munro, W. J. & White, A. G. Measurement of qubits. Phys. Rev. A 64, 052312 (2001)

    ADS  Article  Google Scholar 

  24. Peres, A. Separability criterion for density matrices. Phys. Rev. Lett. 77, 1413–1416 (1996)

    ADS  MathSciNet  CAS  Article  Google Scholar 

  25. Wootters, W. K. Entanglement of formation of an arbitrary state of two qubits. Phys. Rev. Lett. 80, 2245–2248 (1998)

    ADS  CAS  Article  Google Scholar 

  26. Verstraete, F. & Verschelde, H. Fidelity of mixed states of two qubits. Phys. Rev. A 66, 022307 (2002)

    ADS  MathSciNet  Article  Google Scholar 

  27. Stevenson, R. M. et al. Evolution of entanglement between distinguishable light states. Phys. Rev. Lett. 101, 170501 (2008)

    ADS  Article  Google Scholar 

  28. Kowalik, K. et al. Monitoring electrically driven cancellation of exciton fine structure in a semiconductor quantum dot by optical orientation. Appl. Phys. Lett. 91, 183104 (2007)

    ADS  Article  Google Scholar 

  29. Santori, C., Fattal, D., Vučković, J., Solomon, G. S. & Yamamoto, Y. Indistinguishable photons from a single-photon device. Nature 419, 594–597 (2002)

    ADS  CAS  Article  Google Scholar 

  30. Bennet, C. H. et al. Purification of noisy entanglement and faithful teleportation via noisy channels. Phys. Rev. Lett. 76, 722–725 (1996)

    ADS  Article  Google Scholar 

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Acknowledgements

This work was partly supported by the European Project NanoEPR and by the French ANR P3N DELIGHT. We acknowledge A. Calvar and M. Larqué for help with experiments, N. Dupuis for help with molecule modelling theory and I. Robert-Philip for discussions. A.B. acknowledges discussions with B. Kraus and S. Iblisdir.

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Authors and Affiliations

Authors

Contributions

A.D. and P.S. were involved in all steps of this work. J.S. ran quantum dot anisotropic exchange splitting measurements and participated in photon correlation measurements. A.B., O.K. and P.V. helped with the correlation experimental set-up and participated in data analysis. P.V. also participated in the theoretical study of photonic molecules. A.L. grew the samples. I.S. etched the micropillars and J.B. implemented the radiation pattern measurements. All authors participated in scientific discussions and manuscript preparation.

Corresponding author

Correspondence to Pascale Senellart.

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The authors declare no competing financial interests.

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Dousse, A., Suffczyński, J., Beveratos, A. et al. Ultrabright source of entangled photon pairs. Nature 466, 217–220 (2010). https://doi.org/10.1038/nature09148

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