Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

A solid-state source of strongly entangled photon pairs with high brightness and indistinguishability

Abstract

The generation of high-quality entangled photon pairs has been a long-sought goal in modern quantum communication and computation. So far, the most widely used entangled photon pairs have been generated from spontaneous parametric down-conversion (SPDC), a process that is intrinsically probabilistic and thus relegated to a regime of low rates of pair generation. In contrast, semiconductor quantum dots can generate triggered entangled photon pairs through a cascaded radiative decay process and do not suffer from any fundamental trade-off between source brightness and multi-pair generation. However, a source featuring simultaneously high photon extraction efficiency, high degree of entanglement fidelity and photon indistinguishability has been lacking. Here, we present an entangled photon pair source with high brightness and indistinguishability by deterministically embedding GaAs quantum dots in broadband photonic nanostructures that enable Purcell-enhanced emission. Our source produces entangled photon pairs with a pair collection probability of up to 0.65(4) (single-photon extraction efficiency of 0.85(3)), entanglement fidelity of 0.88(2), and indistinguishabilities of 0.901(3) and 0.903(3) (brackets indicate uncertainty on last digit). This immediately creates opportunities for advancing quantum photonic technologies.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Circular Bragg resonator on highly efficient broadband reflector for generation of entangled photon pairs.
Fig. 2: Basic characterization of the QD-CBR-HBR device.
Fig. 3: Entanglement characterization.
Fig. 4: Photon indistinguishability.

Similar content being viewed by others

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

References

  1. Einstein, A., Podolsky, B. & Rosen, N. Can quantum-mechanical description of physical reality be considered complete? Phys. Rev. 47, 777 (1935).

    Article  CAS  Google Scholar 

  2. Giustina, M. et al. Significant-loophole-free test of Bell’s theorem with entangled photons. Phys. Rev. Lett. 115, 250401 (2015).

    Article  Google Scholar 

  3. Shalm, L. K. et al. Strong loophole-free test of local realism. Phys. Rev. Lett. 115, 250402 (2015).

    Article  Google Scholar 

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

  5. Kimble, H. J. The quantum internet. Nature 453, 1023–1030 (2008).

    Article  CAS  Google Scholar 

  6. Simon, C. et al. Quantum repeaters with photon pair sources and multimode memories. Phys. Rev. Lett. 98, 190503 (2007).

    Article  Google Scholar 

  7. Acin, A. et al. Device-independent security of quantum cryptography against collective attacks. Phys. Rev. Lett. 98, 230501 (2007).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  9. Scarani, V. et al. Four-photon correction in two-photon Bell experiments. Eur. Phys. J. D 32, 129–138 (2005).

    Article  CAS  Google Scholar 

  10. Wang, X. L. et al. Experimental ten-photon entanglement. Phys. Rev. Lett. 117, 210502 (2016).

    Article  Google Scholar 

  11. Pan, J. W. et al. Multiphoton entanglement and interferometry. Rev. Mod. Phys. 2012, 072501 (2012).

    Google Scholar 

  12. 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  CAS  Google Scholar 

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

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  15. 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).

    Article  Google Scholar 

  16. Müller, M., Bounouar, S., Jöns, K. D., Gläss, M. & Michler, P. On-demand generation of indistinguishable polarization-entangled photon pairs. Nat. Photon. 8, 224–228 (2014).

    Article  Google Scholar 

  17. Chung, T. H. et al. Selective carrier injection into patterned arrays of pyramidal quantum dots for entangled photon light-emitting diodes. Nat. Photon. 10, 782–787 (2016).

    Article  CAS  Google Scholar 

  18. Orieux, A., Versteegh, M. A. M., Jöns, K. D. & Ducci, S. Semiconductor devices for entangled photon pair generation: a review. Rep. Prog. Phys. 80, 076001 (2017).

    Article  Google Scholar 

  19. Huo, Y. H., Rastelli, A. & Schmidt, O. G. Ultra-small excitonic fine structure splitting in highly symmetric quantum dots on GaAs (001) substrate. Appl. Phys. Lett. 102, 152105 (2013).

    Article  Google Scholar 

  20. Keil, R. et al. Solid-state ensemble of highly entangled photon sources at rubidium atomic transitions. Nat. Commun. 10, 15501 (2017).

    Article  Google Scholar 

  21. Huber, D. et al. Highly indistinguishable and strongly entangled photons from symmetric GaAs quantum dots. Nat. Commun. 10, 15506 (2017).

    Article  Google Scholar 

  22. Ding, X. et al. On-demand single photons with high extraction efficiency and near-unity indistinguishability from a resonantly driven quantum dot in a micropillar. Phys. Rev. Lett. 116, 020401 (2016).

    Article  Google Scholar 

  23. Somaschi, N. et al. Near-optimal single-photon sources in the solid state. Nat. Photon. 10, 340–345 (2016).

    Article  CAS  Google Scholar 

  24. He, Y.-M. et al. Deterministic implementation of a bright, on-demand single-photon source with near-unity indistinguishability via quantum dot imaging. Optica 4, 802–808 (2017).

    Article  CAS  Google Scholar 

  25. Claudon, J. et al. A highly efficient single-photon source based on a quantum dot in a photonic nanowire. Nat. Photon. 4, 174–177 (2010).

    Article  CAS  Google Scholar 

  26. Reimer, M. E. et al. Bright single-photon sources in bottom-up tailored nanowires. Nat. Commun. 3, 737 (2012).

    Article  Google Scholar 

  27. Laucht, A. et al. A waveguide-coupled on-chip single-photon source. Phys. Rev. X 2, 011014 (2012).

    Google Scholar 

  28. Arcari, M. et al. Near-unity coupling efficiency of a quantum emitter to a photonic crystal waveguide. Phys. Rev. Lett. 113, 093603 (2014).

    Article  CAS  Google Scholar 

  29. Gschrey, M. et al. Highly indistinguishable photons from deterministic quantum-dot microlenses utilizing three-dimensional in situ electron-beam lithography. Nat. Commun. 6, 7662 (2015).

    Article  CAS  Google Scholar 

  30. Davanco, M., Rakher, M. T., Schuh, D., Badolato, A. & Srinivasan, K. A circular dielectric grating for vertical extraction of single quantum dot emission. Appl. Phys. Lett. 99, 041102 (2011).

    Article  Google Scholar 

  31. Sapienza, L., Davanço, M., Badolato, A. & Srinivasan, K. Nanoscale optical positioning of single quantum dots for bright and pure single-photon emission. Nat. Commun. 6, 7833 (2015).

    Article  CAS  Google Scholar 

  32. Dousse, A. et al. Ultrabright source of entangled photon pairs. Nature 466, 217–220 (2010).

    Article  CAS  Google Scholar 

  33. Jöns, K. D. et al. Bright nanoscale source of deterministic entangled photon pairs violating Bell’s inequality. Sci. Rep. 7, 1700 (2017).

    Article  Google Scholar 

  34. Chen, Y., Zopf, M., Keil, R., Ding, F. & Schmidt, O. G. Highly-efficient extraction of entangled photons from quantum dots using a broadband optical antenna. Nat. Commun. 9, 2994 (2018).

    Article  Google Scholar 

  35. Liu, J. et al. Cryogenic photoluminescence imaging system for nanoscale positioning of single quantum emitters. Rev. Sci. Instrum. 88, 023116 (2017).

    Article  Google Scholar 

  36. Chen, Y. et al. Wavelength-tunable entangled photons from silicon-integrated III–V quantum dots. Nat. Commun. 7, 10387 (2016).

    Article  CAS  Google Scholar 

  37. Trotta, R. et al. Wavelength-tunable sources of entangled photons interfaced with atomic vapors. Nat. Commun. 7, 10375 (2016).

    Article  CAS  Google Scholar 

  38. Huber, D. et al. Strain-tunable GaAs quantum dot: an on-demand source of nearly-maximally entangled photon pairs. Phys. Rev. Lett. 121, 033902 (2018).

    Article  CAS  Google Scholar 

  39. Jayakumar, H. et al. Time-bin entangled photons from a quantum dot. Nat. Commun. 5, 4251 (2014).

    Article  CAS  Google Scholar 

  40. Stufler, S. et al. ‘Two-photon Rabi oscillations in a single InxGas1−xA/GaAs quantum dot’. Phys. Rev. B 73, 125304 (2006).

    Article  Google Scholar 

  41. Kaniber, M. et al. Efficient and selective cavity-resonant excitation for single photon generation. New J. Phys. 11, 013031 (2009).

    Article  Google Scholar 

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

    Article  Google Scholar 

  43. Ward, M. M. et al. Coherent dynamics of a telecom-wavelength entangled photon source. Nat. Commun. 5, 3316 (2014).

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  45. Duan, L. M., Lukin, M. D., Cirac, J. I. & Zoller, P. Long-distance quantum communication with atomic ensembles and linear optics. Nature 414, 413–418 (2001).

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  47. Liu, J. et al. Single self-assembled InAs/GaAs quantum dots in photonic nanostructures: the role of nanofabrication. Phys. Rev. Appl. 9, 064019 (2018).

    Article  CAS  Google Scholar 

  48. Kaldewey, T. et al. Coherent and robust high-fidelity generation of a biexciton in a quantum dot by rapid adiabatic passage. Phys. Rev. B 95, 161302(R) (2017).

    Article  Google Scholar 

  49. Troiani, F. Entanglement swapping with energy-polarization-entangled photons from quantum dot cascade decay. Phys. Rev. B 90, 245419 (2014).

    Article  Google Scholar 

  50. Iles-Smith, J., McCutcheon, D. P. S., Nazir, A. & Mork, J. Phonon scattering inhibits simultaneous near-unity efficiency and indistinguishability in semiconductor single-photon sources. Nat. Photon. 11, 521–526 (2017).

    Article  CAS  Google Scholar 

  51. Pathak, P. K. & Agarwal, G. S. Quantum random walk of two photons in separable and entangled states. Phys. Rev. A 75, 032351 (2007).

    Article  Google Scholar 

  52. Prilmüller, M. et al. Hyperentanglement of photons emitted by a quantum dot. Phys. Rev. Lett. 121, 110503 (2018).

    Article  Google Scholar 

  53. Olbricha, F. et al. Polarization-entangled photons from an InGaAs-based quantum dot emitting in the telecom C-band. Appl. Phys. Lett. 111, 133106 (2017).

    Article  Google Scholar 

  54. Huwer, J. et al. Quantum-dot-based telecommunication-wavelength quantum relay. Phys. Rev. Appl. 8, 024007 (2017).

    Article  Google Scholar 

  55. Li, Q., Davanço, M. & Srinivasan, K. Efficient and low-noise single-photon-level frequency conversion interfaces using silicon nanophotonics. Nat. Photon. 10, 406–414 (2016).

    Article  CAS  Google Scholar 

  56. Gao, W. B. et al. Quantum teleportation from a propagating photon to a solid-state spin qubit. Nat. Commun. 11, 2744 (2013).

    Article  Google Scholar 

  57. Wang, H. et al. On-demand semiconductor source of entangled photons which simultaneously has high fidelity, efficiency, and indistinguishability. Phys. Rev. Lett. 122, 113602 (2019).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We acknowledge R. Trotta, X. Yuan, H. Huang, M. Reindl, D. Huber and Y. Huo for discussions. We are grateful for financial support from the National Key R&D Program of China (2016YFA0301300, 2018YFA0306100), the National Natural Science Foundations of China (91750207, 11674402, 11761141015, 11761131001, 11874437, 11704424), Guangzhou Science and Technology project (201805010004), the Natural Science Foundations of Guangdong (2018B030311027, 2017A030310004, 2016A030310216, 2016A030312012), the national supercomputer center in Guangzhou, the Austrian Science Fund (FWF): P29603, and the LIT Secure and Correct Systems Lab funded by the State of Upper Austria.

Author information

Authors and Affiliations

Authors

Contributions

R.B.S., J. Li and X.W. conceived the nanostructure and its fabrication strategy. J. Liu proposed the entanglement generation and designed the experiments. R.S and K.S. contributed to the structure simulations. S.F.C.d.S. and Y.Y. grew the QD wafers. R.S., B.Y., J. Liu and J. Li fabricated the devices. Y.W., RS., B.Y. and J. Liu characterized the devices. J.I.-S. performed the indistinguishability calculation. J. Liu, Y.W. and R.S. analysed the data. J. Liu wrote the manuscript with inputs from all authors. J. Liu, A.R. and X.W. supervised the project.

Corresponding authors

Correspondence to Armando Rastelli, Juntao Li or Xuehua Wang.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Journal peer review information: Nature Nanotechnology thanks Weibo Gao, Alastair Sinclair and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary text and Supplementary Figures 1–9

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Liu, J., Su, R., Wei, Y. et al. A solid-state source of strongly entangled photon pairs with high brightness and indistinguishability. Nat. Nanotechnol. 14, 586–593 (2019). https://doi.org/10.1038/s41565-019-0435-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41565-019-0435-9

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing