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An entangled-light-emitting diode

Nature volume 465, pages 594–597 (2010)Cite this article

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Abstract

An optical quantum computer, powerful enough to solve problems so far intractable using conventional digital logic, requires a large number of entangled photons1,2. At present, entangled-light sources are optically driven with lasers3,4,5,6,7, which are impractical for quantum computing owing to the bulk and complexity of the optics required for large-scale applications. Parametric down-conversion is the most widely used source of entangled light, and has been used to implement non-destructive quantum logic gates8,9. However, these sources are Poissonian4,5 and probabilistically emit zero or multiple entangled photon pairs in most cycles, fundamentally limiting the success probability of quantum computational operations. These complications can be overcome by using an electrically driven on-demand source of entangled photon pairs10, but so far such a source has not been produced. Here we report the realization of an electrically driven source of entangled photon pairs, consisting of a quantum dot embedded in a semiconductor light-emitting diode (LED) structure. We show that the device emits entangled photon pairs under d.c. and a.c. injection, the latter achieving an entanglement fidelity of up to 0.82. Entangled light with such high fidelity is sufficient for application in quantum relays11, in core components of quantum computing such as teleportation12,13,14, and in entanglement swapping15,16. The a.c. operation of the entangled-light-emitting diode (ELED) indicates its potential function as an on-demand source without the need for a complicated laser driving system; consequently, the ELED is at present the best source on which to base future scalable quantum information applications17.

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Figure 1: Device design and operation.
Figure 2: Polarized pair-correlation results from d.c. electrical injection into the ELED.
Figure 3: Polarized pair-correlation results from a.c. electrical injection into the ELED.

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References

  1. Knill, E., Laflamme, R. & Milburn, G. J. A scheme for efficient quantum computation with linear optics. Nature 409, 46–52 (2001)

    Article  ADS  CAS  Google Scholar 

  2. Kok, P. et al. Linear optical quantum computing with photonic qubits. Rev. Mod. Phys. 79, 135–174 (2007)

    Article  ADS  CAS  Google Scholar 

  3. Aspect, A., Grangier, P. & Roger, G. Experimental realization of Einstein-Podolsky-Rosen-Bohm gedankenexperiment: a new violation of Bell’s inequalities. Phys. Rev. Lett. 49, 91–94 (1982)

    Article  ADS  Google Scholar 

  4. Shih, Y. H. & Alley, C. O. New type of Einstein-Podolsky-Rosen-Bohm experiment using pairs of light quanta produced by optical parametric down conversion. Phys. Rev. Lett. 61, 2921–2924 (1988)

    Article  ADS  CAS  Google Scholar 

  5. Kiess, T. E., Shih, Y. H., Sergienko, A. V. & Alley, C. O. Einstein-Podolsky-Rosen-Bohm experiment using pairs of light quanta produced by type-II parametric down-conversion. Phys. Rev. Lett. 71, 3893–3897 (1993)

    Article  ADS  CAS  Google Scholar 

  6. Edamatsu, K., Oohata, G., Shimizu, R. & Itoh, T. Generation of ultraviolet entangled photons in a semiconductor. Nature 431, 167–170 (2004)

    Article  ADS  CAS  Google Scholar 

  7. Stevenson, R. M. et al. A semiconductor source of triggered entangled photon pairs. Nature 439, 179–182 (2006)

    Article  ADS  CAS  Google Scholar 

  8. Gasparoni, P. J.-W., Walther, P., Rudolph, T. & Zeilinger, A. Realization of a photonic controlled-NOT gate sufficient for quantum computation. Phys. Rev. Lett. 93, 020504 (2004)

    Article  ADS  Google Scholar 

  9. Zhao, Z. et al. Experimental demonstration of a nondestructive controlled-NOT quantum gate for two independent photon qubits. Phys. Rev. Lett. 94, 030501 (2005)

    Article  ADS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  11. Jacobs, B. C., Pittman, T. B. & Franson, J. D. Quantum relays and noise suppression using linear optics. Phys. Rev. A 66, 052307 (2002)

    Article  ADS  Google Scholar 

  12. Bennett, C. H. et al. Teleporting an unknown quantum state via dual classical and Einstein-Podolsky-Rosen channels. Phys. Rev. Lett. 70, 1895–1899 (1993)

    Article  ADS  MathSciNet  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  14. Horodecki, M., Horodecki, P. & Horodecki, R. General teleportation channel, singlet fraction, and quasidistillation. Phys. Rev. A 60, 1888–1898 (1999)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  15. Żukowski, M., Zeilinger, A., Horne, M. A. & Ekert, A. K. “Event-ready-detectors” Bell experiment via entanglement swapping. Phys. Rev. Lett. 71, 4287–4290 (1993)

    Article  ADS  Google Scholar 

  16. Pan, J.-W., Bouwmeester, D. & Weinfurter, H. & Zeilinger, A. Experimental entanglement swapping: entangling photons that never interacted. Phys. Rev. Lett. 80, 3891–3894 (1998)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  17. Bennett, C. H. & DiVincenzo, D. P. Quantum information and computation. Nature 404, 247–255 (2000)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  19. 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 

  20. Hudson, A. J. et al. Coherence of an entangled exciton-photon state. Phys. Rev. Lett. 99, 266802 (2007)

    Article  ADS  CAS  Google Scholar 

  21. Yuan, Z. et al. Electrically driven single-photon source. Science 295, 102–105 (2002)

    Article  ADS  CAS  Google Scholar 

  22. Young, R. J. et al. Inversion of exciton level splitting in quantum dots. Phys. Rev. B 72, 113305 (2005)

    Article  ADS  Google Scholar 

  23. Young, R. J. et al. Bell-inequality violation with a triggered photon-pair source. Phys. Rev. Lett. 102, 030406 (2009)

    Article  ADS  CAS  Google Scholar 

  24. Michler, P. ed. Single Quantum Dots: Fundamentals, Applications and New Concepts (Springer, 2003)

    Google Scholar 

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

    Article  Google Scholar 

  26. Moreau, E. et al. Quantum cascade of photons in semiconductor quantum dots. Phys. Rev. Lett. 87, 183601 (2001)

    Article  ADS  Google Scholar 

  27. Shields, A. J., Stevenson, R. M. & Young, R. J. in Single Semiconductor Quantum Dots (ed. Michler, P.) Ch. 7 (Springer, 2009)

    Google Scholar 

  28. Ekert, A. K. Quantum cryptography based on Bell’s theorem. Phys. Rev. Lett. 67, 661–663 (1991)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  29. Nicoll, C. A. et al. MBE growth of In(Ga)As quantum dots for entangled light emission. J. Cryst. Growth 311, 1811–1814 (2008)

    Article  ADS  Google Scholar 

  30. Mohan, A. et al. Polarization-entangled photons produced with high-symmetry site-controlled quantum dots. Nature Photon advance online publication, 10.1038/nphoton.2010.2 (7 March 2010)

Download references

Acknowledgements

We would like to acknowledge funding for this work from the Engineering and Physical Sciences Research Council, the Quantum Information Processing Interdisciplinary Research Collaboration, the EU Integrated Projects, Qubit Applications and Quantum Interfaces, Sensors and Communication based on Entanglement and Nanoscience in the European Research Area, and we thank K. Cooper for his advice and support in device fabrication.

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Authors and Affiliations

  1. Toshiba Research Europe Limited, 208 Cambridge Science Park, Cambridge CB4 0GZ, UK ,

    C. L. Salter, R. M. Stevenson & A. J. Shields

  2. Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, UK ,

    C. L. Salter, I. Farrer, C. A. Nicoll & D. A. Ritchie

Authors
  1. C. L. Salter
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  2. R. M. Stevenson
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  3. I. Farrer
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  4. C. A. Nicoll
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  5. D. A. Ritchie
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  6. A. J. Shields
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Contributions

C.L.S. and R.M.S. performed measurements and analysis with support from other authors. All authors contributed to the heterostructure design. The heterostructures were grown by I.F., C.A.N. and D.A.R. LEDs were processed by C.L.S. This work was directed by A.J.S. All authors contributed to writing the manuscript.

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Correspondence to R. M. Stevenson or A. J. Shields.

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The authors declare no competing financial interests.

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Salter, C., Stevenson, R., Farrer, I. et al. An entangled-light-emitting diode. Nature 465, 594–597 (2010). https://doi.org/10.1038/nature09078

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