Letter | Published:

Circuit quantum electrodynamics with a spin qubit

Nature volume 490, pages 380383 (18 October 2012) | Download Citation


Electron spins trapped in quantum dots have been proposed as basic building blocks of a future quantum processor1,2,3. Although fast, 180-picosecond, two-quantum-bit (two-qubit) operations can be realized using nearest-neighbour exchange coupling4, a scalable, spin-based quantum computing architecture will almost certainly require long-range qubit interactions. Circuit quantum electrodynamics (cQED) allows spatially separated superconducting qubits to interact via a superconducting microwave cavity that acts as a ‘quantum bus’, making possible two-qubit entanglement and the implementation of simple quantum algorithms5,6,7. Here we combine the cQED architecture with spin qubits by coupling an indium arsenide nanowire double quantum dot to a superconducting cavity8,9. The architecture allows us to achieve a charge–cavity coupling rate of about 30 megahertz, consistent with coupling rates obtained in gallium arsenide quantum dots10. Furthermore, the strong spin–orbit interaction of indium arsenide allows us to drive spin rotations electrically with a local gate electrode, and the charge–cavity interaction provides a measurement of the resulting spin dynamics. Our results demonstrate how the cQED architecture can be used as a sensitive probe of single-spin physics and that a spin–cavity coupling rate of about one megahertz is feasible, presenting the possibility of long-range spin coupling via superconducting microwave cavities.

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Research at Princeton University was supported by the Alfred P. Sloan Foundation, the David and Lucile Packard Foundation, US Army Research Office grant W911NF-08-1-0189, DARPA QuEST award HR0011-09-1-0007 and the US National Science Foundation through the Princeton Center for Complex Materials (DMR-0819860) and CAREER award DMR-0846341. J.M.T. acknowledges support from ARO MURI award W911NF-09-1-0406.

Author information


  1. Department of Physics, Princeton University, Princeton, New Jersey 08544, USA

    • K. D. Petersson
    • , L. W. McFaul
    • , M. D. Schroer
    • , M. Jung
    •  & J. R. Petta
  2. Joint Quantum Institute/NIST, College Park, Maryland 20742, USA

    • J. M. Taylor
  3. Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA

    • A. A. Houck
  4. Princeton Institute for the Science and Technology of Materials (PRISM), Princeton University, Princeton, New Jersey 08544, USA

    • J. R. Petta


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K.D.P. fabricated the sample and performed the measurements. K.D.P., L.W.M. and A.A.H. developed the resonator fabrication and measurement processes. K.D.P., M.D.S. and M.J. developed the nanowire device fabrication processes. M.D.S. grew the nanowires. J.M.T. developed the theory for the experiment. K.D.P. and J.R.P. wrote the paper with input from the other authors. J.R.P. planned the experiment.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to J. R. Petta.

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