Non-exponential decay of a giant artificial atom


In quantum optics, light–matter interaction has conventionally been studied using small atoms interacting with electromagnetic fields with wavelength several orders of magnitude larger than the atomic dimensions1,2. In contrast, here we experimentally demonstrate the vastly different ‘giant atom’ regime, where an artificial atom interacts with acoustic fields with wavelength several orders of magnitude smaller than the atomic dimensions. This is achieved by coupling a superconducting qubit3 to surface acoustic waves at two points with separation on the order of 100 wavelengths. This approach is comparable to controlling the radiation of an atom by attaching it to an antenna. The slow velocity of sound leads to a significant internal time-delay for the field to propagate across the giant atom, giving rise to non-Markovian dynamics4. We demonstrate the non-Markovian character of the giant atom in the frequency spectrum as well as non-exponential relaxation in the time domain.

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Fig. 1: Device layouts.
Fig. 2: Scattering properties of the giant atom.
Fig. 3: Frequency response and dynamics of the giant atom.

Data availability

The data generated and analysed in this study are available from the corresponding authors upon reasonable request.


  1. 1.

    Brune, M., Haroche, S., Lefevre, V., Raimond, J. M. & Zagury, N. Quantum nondemolition measurement of small photon numbers by Rydberg-atom phase-sensitive detection. Phys. Rev. Lett. 65, 976–979 (1990).

    ADS  Article  Google Scholar 

  2. 2.

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

    ADS  MathSciNet  Article  Google Scholar 

  3. 3.

    Schoelkopf, R. J. & Girvin, S. M. Wiring up quantum systems. Nature 451, 664–669 (2008).

    ADS  Article  Google Scholar 

  4. 4.

    Guo, L., Grimsmo, A. L., Kockum, A. F., Pletyukhov, M. & Johansson, G. Giant acoustic atom: a single quantum system with a deterministic time delay. Phys. Rev. A 95, 053821 (2017).

    ADS  Article  Google Scholar 

  5. 5.

    Goy, P., Raimond, J. M., Gross, M. & Haroche, S. Observation of cavity-enhanced single-atom spontaneous emission. Phys. Rev. Lett. 50, 1903–1906 (1983).

    ADS  Article  Google Scholar 

  6. 6.

    Miller, R. et al. Trapped atoms in cavity QED: coupling quantized light and matter. J. Phys. B 38, S551 (2005).

    Article  Google Scholar 

  7. 7.

    Gu, X., Kockum, A., Miranowicz, A., Liu, Y. & Nori, F. Microwave photonics with superconducting quantum circuits. Phys. Rep. 718, 1–102 (2017).

    ADS  MathSciNet  Article  Google Scholar 

  8. 8.

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

    ADS  Article  Google Scholar 

  9. 9.

    Hofheinz, M. et al. Synthesizing arbitrary quantum states in a superconducting resonator. Nature 459, 546–549 (2009).

    ADS  Article  Google Scholar 

  10. 10.

    Wang, C. et al. A Schrödinger cat living in two boxes. Science 352, 1087–1091 (2016).

    ADS  MathSciNet  Article  Google Scholar 

  11. 11.

    Hoi, I. C. et al. Demonstration of a single-photon router in the microwave regime. Phys. Rev. Lett. 107, 073601 (2011).

    ADS  Article  Google Scholar 

  12. 12.

    Abdumalikov, A. A. et al. Electromagnetically induced transparency on a single artificial atom. Phys. Rev. Lett. 104, 193601 (2010).

    ADS  Article  Google Scholar 

  13. 13.

    Roy, D., Wilson, C. M. & Firstenberg, O. Colloquium: strongly interacting photons in one-dimensional continuum. Rev. Mod. Phys. 89, 021001 (2017).

    MathSciNet  Article  Google Scholar 

  14. 14.

    Paik, H. et al. Observation of high coherence in Josephson junction qubits measured in a three-dimensional circuit QED architecture. Phys. Rev. Lett. 107, 240501 (2011).

    ADS  Article  Google Scholar 

  15. 15.

    Koch, J. et al. Charge-insensitive qubit design derived from the Cooper pair box. Phys. Rev. A 76, 042319 (2007).

    ADS  Article  Google Scholar 

  16. 16.

    Gustafsson, M. V. et al. Propagating phonons coupled to an artificial atom. Science 346, 207–211 (2014).

    ADS  Article  Google Scholar 

  17. 17.

    Manenti, R. et al. Circuit quantum acoustodynamics with surface acoustic waves. Nat. Commun. 8, 975 (2017).

    ADS  Article  Google Scholar 

  18. 18.

    Chu, Y. et al. Quantum acoustics with superconducting qubits. Science 358, 199–202 (2017).

    ADS  MathSciNet  Article  Google Scholar 

  19. 19.

    Moores, B. A., Sletten, L. R., Viennot, J. J. & Lehnert, K. W. Cavity quantum acoustic device in the multimode strong coupling regime. Phys. Rev. Lett. 120, 227701 (2018).

    ADS  Article  Google Scholar 

  20. 20.

    Bolgar, A. N. et al. Quantum regime of a two-dimensional phonon cavity. Phys. Rev. Lett. 120, 223603 (2018).

    ADS  Article  Google Scholar 

  21. 21.

    Noguchi, A., Yamazaki, R., Tabuchi, Y. & Nakamura, Y. Qubit-assisted transduction for a detection of surface acoustic waves near the quantum limit. Phys. Rev. Lett. 119, 180505 (2017).

    ADS  Article  Google Scholar 

  22. 22.

    Manenti, R. et al. Surface acoustic wave resonators in the quantum regime. Phys. Rev. B 93, 041411 (2016).

    ADS  Article  Google Scholar 

  23. 23.

    Satzinger, K. J. et al. Quantum control of surface acoustic wave phonons. Nature 563, 661–665 (2018).

    ADS  Article  Google Scholar 

  24. 24.

    Kockum, A. F., Delsing, P. & Johansson, G. Designing frequency-dependent relaxation rates and Lamb shifts for a giant artificial atom. Phys. Rev. A 90, 013837 (2014).

    ADS  Article  Google Scholar 

  25. 25.

    Breuer, H.-P., Laine, E.-M., Piilo, J. & Vacchini, B. Colloquium: non-Markovian dynamics in open quantum systems. Rev. Mod. Phys. 88, 021002 (2016).

    ADS  Article  Google Scholar 

  26. 26.

    Pichler, H. & Zoller, P. Photonic circuits with time delays and quantum feedback. Phys. Rev. Lett. 116, 093601 (2016).

    ADS  Article  Google Scholar 

  27. 27.

    Pichler, H., Choi, S., Zoller, P. & Lukin, M. D. Universal photonic quantum computation via time-delayed feedback. Proc. Natl Acad. Sci. USA 114, 11362–11367 (2017).

    ADS  MathSciNet  Article  Google Scholar 

  28. 28.

    Kockum, A. F., Johansson, G. & Nori, F. Decoherence-free interaction between giant atoms in waveguide quantum electrodynamics. Phys. Rev. Lett. 120, 140404 (2018).

    ADS  Article  Google Scholar 

  29. 29.

    Aref, T. et al. in Superconducting Devices in Quantum Optics (eds Hadfield, R. H. & Johansson, G.) 217–244 (Springer International Publishing, 2016).

  30. 30.

    Astafiev, O. et al. Resonance fluorescence of a single artificial atom. Science 327, 840–843 (2010).

    ADS  Article  Google Scholar 

  31. 31.

    Breuer, H.-P., Laine, E.-M. & Piilo, J. Measure for the degree of non-Markovian behavior of quantum processes in open systems. Phys. Rev. Lett. 103, 210401 (2009).

    ADS  MathSciNet  Article  Google Scholar 

  32. 32.

    Reed, M. D. et al. High-fidelity readout in circuit quantum electrodynamics using the Jaynes-Cummings nonlinearity. Phys. Rev. Lett. 105, 173601 (2010).

    ADS  Article  Google Scholar 

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This work was supported by the Knut and Alice Wallenberg foundation and by the Swedish Research Council (VR). This project has also received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 642688. We acknowledge fruitful discussions with M. K. Ekström and G. Johansson.

Author information




G.A., B.S. and T.A. contributed to the design and fabrication of devices. L.G. developed the theoretical expressions for spectra and relaxation rates. G.A. and B.S. performed the measurements. All authors contributed to discussions and the interpretation of results. P.D. supervised the project, and G.A., B.S., L.G. and P.D. contributed to the writing of the manuscript.

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Correspondence to Lingzhen Guo or Per Delsing.

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The authors declare no competing interests.

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Peer review information: Nature Physics thanks Adam Miranowicz and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Andersson, G., Suri, B., Guo, L. et al. Non-exponential decay of a giant artificial atom. Nat. Phys. 15, 1123–1127 (2019).

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