Skip to main content

Thank you for visiting 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.

Near-optimal single-photon sources in the solid state


The scaling of optical quantum technologies requires efficient, on-demand sources of highly indistinguishable single photons. Semiconductor quantum dots inserted into photonic structures are ultrabright single-photon sources, yet the indistinguishability is limited by charge noise. Parametric downconversion sources provide highly indistinguishable photons but are operated at very low brightness to maintain high single-photon purity. To date, no technology has provided a bright source generating near-unity indistinguishability and pure single photons. Here, we report such devices made of quantum dots in electrically controlled cavities. Application of an electrical bias on the deterministically fabricated structures is shown to strongly reduce charge noise. Under resonant excitation, an indistinguishability of 0.9956 ± 0.0045 is demonstrated with g(2)(0) = 0.0028 ± 0.0012. The photon extraction of 65% and measured brightness of 0.154 ± 0.015 make this source 20 times brighter than any source of equal quality. This new generation of sources opens the way to new levels of complexity and scalability in optical quantum technologies.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


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

Figure 1: Electrically controlled single-photon sources.
Figure 2: Characteristics of single-photon source QD1 under non-resonant excitation.
Figure 3: Characteristics of single-photon source QD3 under resonant excitation.
Figure 4: Comparison with other QD and SPDC single-photon sources.


  1. O'Brien, J. L., Furusawa, A. & Vučković, J. Photonic quantum technologies. Nature Photon. 3, 687–695 (2009).

    Article  ADS  Google Scholar 

  2. Aspuru-Guzik, A. & Walther, P. Photonic quantum simulators. Nature Phys. 8, 285–291 (2012).

    Article  ADS  Google Scholar 

  3. Hosseini, M., Campbell, G., Sparkes, B. M., Lam, P. K. & Buchler, B. C. Unconditional room-temperature quantum memory. Nature Phys. 7, 794–798 (2011).

    Article  ADS  Google Scholar 

  4. Varnava, M., Browne, D. E. & Rudolph, T. How good must single photon sources and detectors be for efficient linear optical quantum computation? Phys. Rev. Lett. 100, 060502 (2008).

    Article  ADS  Google Scholar 

  5. Eisaman, M. D., Fan, J., Migdall, A. & Polyakov, S. V. Single-photon sources and detectors. Rev. Sci. Instrum. 82, 071101 (2011).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  8. Broome, M. A. et al. Photonic boson sampling in a tunable circuit. Science 339, 794–798 (2013).

    Article  ADS  Google Scholar 

  9. Spring, J. B. et al. Boson sampling on a photonic chip. Science 339, 798–801 (2013).

    Article  ADS  Google Scholar 

  10. Tillmann, M. et al. Experimental boson sampling. Nature Photon. 7, 540–544 (2013).

    Article  ADS  Google Scholar 

  11. Spagnolo, N. et al. Experimental validation of photonic boson sampling. Nature Photon. 8, 615–620 (2014).

    Article  ADS  Google Scholar 

  12. Pan, J.-W. et al. Multiphoton entanglement and interferometry. Rev. Mod. Phys. 84, 777–838 (2012).

    Article  ADS  Google Scholar 

  13. Ma, X., Zotter, S., Kofler, J., Jennewein, T. & Zeilinger, A. Experimental generation of single photons via active multiplexing. Phys. Rev. A 83, 043814 (2011).

    Article  ADS  Google Scholar 

  14. Takeoka, M., Jin, R.-B. & Sasaki, M. Full analysis of multi-photon pair effects in spontaneous parametric down conversion based photonic quantum information processing. New J. Phys. 17, 043030 (2015).

    Article  ADS  Google Scholar 

  15. Shalm, L. K. et al. Three-photon energy–time entanglement. Nature Phys. 9, 19–22 (2013).

    Article  ADS  Google Scholar 

  16. Guerreiro, T. et al. Nonlinear interaction between single photons. Phys. Rev. Lett. 113, 173601 (2014).

    Article  ADS  Google Scholar 

  17. Santori, C., Pelton, M., Solomon, G., Dale, Y. & Yamamoto, E. Triggered single photons from a quantum dot. Phys. Rev. Lett. 86, 1502–1505 (2001).

    Article  ADS  Google Scholar 

  18. Michler, P. et al. A quantum dot single-photon turnstile device. Science 290, 2282–2285 (2000).

    Article  ADS  Google Scholar 

  19. Madsen, K. H. et al. Efficient out-coupling of high-purity single photons from a coherent quantum dot in a photonic-crystal cavity. Phys. Rev. B 90, 155303 (2014).

    Article  ADS  Google Scholar 

  20. Gazzano, O. et al. Bright solid-state sources of indistinguishable single photons. Nature Commun. 4, 1425 (2013).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  23. Kuhlmann, A. V. et al. Charge noise and spin noise in a semiconductor quantum device. Nature Phys. 9, 570–575 (2013).

    Article  ADS  Google Scholar 

  24. He, Y.-M. et al. On-demand semiconductor single-photon source with near-unity indistinguishability. Nature Nanotech. 8, 213–217 (2013).

    Article  ADS  Google Scholar 

  25. Wei, Y.-J. et al. Deterministic and robust generation of single photons from a single quantum dot with 99.5% indistinguishability using adiabatic rapid passage. Nano Lett. 14, 6515–6519 (2014).

    Article  ADS  Google Scholar 

  26. 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).

    Article  ADS  Google Scholar 

  27. Nowak, A. K. et al. Deterministic and electrically tunable bright single-photon source. Nature Commun. 5, 3240 (2014).

    Article  ADS  Google Scholar 

  28. Hong, C. K., Ou, Z. Y. & Mandel, L. Measurement of subpicosecond time intervals between two photons by interference. Phys. Rev. Lett. 59, 2044–2046 (1987).

    Article  ADS  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).

    Article  ADS  Google Scholar 

  30. Kiraz, A., Atatüre, M. & Imamoğlu, A. Quantum-dot single-photon sources: prospects for applications in linear optics quantum-information processing. Phys. Rev. A 69, 032305 (2004).

    Article  ADS  Google Scholar 

  31. Giesz, V. et al. Coherent control of a solid-state quantum bit with few-photon pulses. Preprint at (2015).

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

    Article  ADS  Google Scholar 

  33. Barbieri, M. Effects of frequency correlation in linear optical entangling gates operated with independent photons. Phys. Rev. A 76, 043825 (2007).

    Article  ADS  Google Scholar 

  34. Weinhold, T. J. et al. Understanding photonic quantum-logic gates: the road to fault tolerance. Preprint at (2008).

  35. Barbieri, M. et al. Parametric downconversion and optical quantum gates: two's company, four's a crowd. J. Mod. Opt. 56, 209–214 (2009).

    Article  ADS  Google Scholar 

  36. Tillmann, M. et al. Generalized multi-photon quantum interference. Phys. Rev. X 5, 041015 (2014).

    Google Scholar 

Download references


This work was partially supported by European Research Council starting grant no. 277885 QD-CQED, the French Agence Nationale pour la Recherche (grant ANR QDOM), the French RENATECH network, the Labex NanoSaclay, EU FP7 grant no. 618072 (WASPS), the Centre for Engineered Quantum Systems (grant no. CE110001013), the Centre for Quantum Computation and Communication Technology (grant no. CE110001027), and the Asian Office of Aerospace Research and Development (grant FA2386-13-1-4070). J.C.L., M.P.A. and A.G.W. thank M. Ringbauer and M. Goggin for insightful discussions, and thank the team from the Austrian Institute of Technology for providing the time-tagging modules for the SPDC measurements. The LPN–CNRS authors are very thankful to A. Nowak for her help with the technology. N.D.L.K. was supported by the FP7 Marie Curie Fellowship OMSiQuD. M.P.A. acknowledges support from the Australian Research Council Discovery Early Career Awards (no. DE120101899). A.G.W. was supported by the University of Queensland Vice-Chancellor's Research and Teaching Fellowship.

Author information

Authors and Affiliations



Optical measurements on the QD devices were conducted primarily by V.G., N.S. and L.d.S., with help from L.L., S.L.P. and P.S. The electrically controlled samples were fabricated by N.S. with help from C.A. The sample was grown by C.G. and A.L., and the etching was performed by I.S. The measurements on the SPDC sources and analysis of that data were conducted by J.C.L. and M.P.A, with help from A.G.W. Theoretical support for the experiment was provided by G.H., T.G. and A.A. The project was conducted by P.S. with help from L.L. All authors discussed the results and participated in manuscript preparation.

Corresponding author

Correspondence to P. Senellart.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 1705 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Somaschi, N., Giesz, V., De Santis, L. et al. Near-optimal single-photon sources in the solid state. Nature Photon 10, 340–345 (2016).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


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