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.

Single artificial-atom lasing


Solid-state superconducting circuits1,2,3 are versatile systems in which quantum states can be engineered and controlled. Recent progress in this area has opened up exciting possibilities for exploring fundamental physics as well as applications in quantum information technology; in a series of experiments4,5,6,7,8 it was shown that such circuits can be exploited to generate quantum optical phenomena, by designing superconducting elements as artificial atoms that are coupled coherently to the photon field of a resonator. Here we demonstrate a lasing effect with a single artificial atom—a Josephson-junction charge qubit9—embedded in a superconducting resonator. We make use of one of the properties of solid-state artificial atoms, namely that they are strongly and controllably coupled to the resonator modes. The device is essentially different from existing lasers and masers; one and the same artificial atom excited by current injection produces many photons.

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: Single artificial-atom maser and lasing mechanism.
Figure 2: Emission from the self-running maser.
Figure 3: Microwave amplification and injection locking.


  1. Makhlin, Y., Schön, G. & Shnirman, A. Quantum-state engineering with Josephson-junction devices. Rev. Mod. Phys. 73, 357–400 (2001)

    Article  ADS  Google Scholar 

  2. Devoret, M. H., Wallraff, A. & Martinis, J. M. Superconducting qubits: A short review. Preprint at 〈〉 (2004)

  3. Wendin, G. & Shumeiko, V. S. in Handbook of Theoretical and Computational Nanotechnology Vol. 3 (eds Rieth, M. & Schommers, W.) 223–309 (American Scientific Publishers, Los Angeles, 2006)

    Google Scholar 

  4. Wallraff, A. et al. Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics. Nature 431, 162–167 (2004)

    Article  ADS  CAS  Google Scholar 

  5. Chiorescu, I. et al. Coherent dynamics of a flux qubit coupled to a harmonic oscillator. Nature 431, 159–161 (2004)

    Article  ADS  CAS  Google Scholar 

  6. Johansson, J. et al. Vacuum Rabi oscillations in a macroscopic superconducting qubit LC oscillator system. Phys. Rev. Lett. 96, 127006 (2006)

    Article  ADS  CAS  Google Scholar 

  7. Schuster, D. I. et al. Resolving photon number states in a superconducting circuit. Nature 445, 515–518 (2007)

    Article  ADS  CAS  Google Scholar 

  8. Houck, A. A. et al. Generating single microwave photons in a circuit. Preprint at 〈〉 (2007)

  9. Nakamura, Y., Pashkin & Tsai, J. S. Coherent control of macroscopic quantum states in a single-Cooper-pair box. Nature 398, 786–788 (1999)

    Article  ADS  CAS  Google Scholar 

  10. Raimond, J.-M., Brune, M. & Haroche, S. Manipulating quantum entanglement with atoms and photons in a cavity. Rev. Mod. Phys. 73, 565–582 (2001)

    Article  ADS  MathSciNet  Google Scholar 

  11. Mabuchi, H. & Doherty, A. Cavity quantum electrodynamics: Coherence in context. Science 298, 1372–1377 (2002)

    Article  ADS  CAS  Google Scholar 

  12. Walther, H. et al. Cavity quantum electrodynamics. Rep. Prog. Phys. 69, 1325–1382 (2006)

    Article  ADS  Google Scholar 

  13. McKeever, J., Boca, A., Boozer, A. D., Buck, J. R. & Kimble, H. J. Experimental realization of a one-atom laser in the regime of strong coupling. Nature 425, 268–271 (2003)

    Article  ADS  CAS  Google Scholar 

  14. Reithmaier, J. P. et al. Strong coupling in a single quantum dot-semiconductor microcavity system. Nature 432, 197–200 (2004)

    Article  ADS  CAS  Google Scholar 

  15. Yoshie, T. et al. Vacuum Rabi splitting with a single quantum dot in a photonic crystal nanocavity. Nature 432, 200–203 (2004)

    Article  ADS  CAS  Google Scholar 

  16. Rice, P. R. & Carmichael, H. J. Photon statistics of a cavity-QED laser: A comment on the laser-phase transition analogy. Phys. Rev. A 50, 4318–4329 (1994)

    Article  ADS  CAS  Google Scholar 

  17. Mu, Y. & Savage, C. M. One-atom lasers. Phys. Rev. A 46, 5944–5954 (1992)

    Article  ADS  CAS  Google Scholar 

  18. Rodrigues, D. A., Imbers, J. & Armour, A. D. Quantum dynamics of a resonator driven by a superconducting single-electron transistor: A solid-state analogue of the micromaser. Phys. Rev. Lett. 98, 067204 (2007)

    Article  ADS  CAS  Google Scholar 

  19. You, J. Q., Liu, Y. X., Sun, C. P. & Nori, F. Persistent single-photon production by tunable on-chip micromaser with a superconducting qubit circuit. Phys. Rev. B 75, 104516 (2007)

    Article  ADS  Google Scholar 

  20. Hauss, J., Fedorov, A., Hutter, C., Shnirman, A. & Schön, G. Single-qubit lasing and cooling at the Rabi frequency. Preprint at 〈〉 (2007)

  21. Averin, D. V. & Aleshkin, V. Ya. Resonance tunneling of Cooper pairs in a system of small Josephson junctions. JETP Lett. 50, 367–369 (1989)

    ADS  Google Scholar 

  22. Fulton, T. A., Gammel, P. L., Bishop, D. J., Dunkleberger, L. N. & Dolan, G. J. Observation of combined Josephson and charging effects in small tunnel junction circuits. Phys. Rev. Lett. 63, 1307–1310 (1989)

    Article  ADS  CAS  Google Scholar 

  23. Siegman, A. E. Lasers (University Science Books, Mill Valley, 1986)

    Google Scholar 

Download references


We are grateful to A. Zagoskin, A. Smirnov, L. Murokh, S. Kouno, A. Tomita and A. Clerk for discussions.

Author information

Authors and Affiliations


Corresponding author

Correspondence to O. Astafiev.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Astafiev, O., Inomata, K., Niskanen, A. et al. Single artificial-atom lasing. Nature 449, 588–590 (2007).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


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