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Superconducting quantum bits

Nature volume 453, pages 1031–1042 (2008)Cite this article

Abstract

Superconducting circuits are macroscopic in size but have generic quantum properties such as quantized energy levels, superposition of states, and entanglement, all of which are more commonly associated with atoms. Superconducting quantum bits (qubits) form the key component of these circuits. Their quantum state is manipulated by using electromagnetic pulses to control the magnetic flux, the electric charge or the phase difference across a Josephson junction (a device with nonlinear inductance and no energy dissipation). As such, superconducting qubits are not only of considerable fundamental interest but also might ultimately form the primitive building blocks of quantum computers.

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Figure 1: The theory underlying flux qubits.
Figure 2: Experimental properties of flux qubits.
Figure 3: Charge qubits.
Figure 4: Quantronium.
Figure 5: Phase qubits.
Figure 6: Qubit manipulation in the time domain.
Figure 7: Controllably coupled flux qubits.
Figure 8: Circuit QED.

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Acknowledgements

Our work is supported by the US Department of Energy (Division of Materials Sciences and Engineering, in the Office of Basic Energy Sciences) (J.C.), and by the Natural Sciences and Engineering Research Council of Canada, QuantumWorks and EuroSQIP (F.K.W.).

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Authors and Affiliations

  1. Department of Physics,366 LeConte Hall, University of California, Berkeley, 94720, California, USA

    John Clarke

  2. Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, 94720, California, USA

    John Clarke

  3. Institute for Quantum Computing, University of Waterloo, 200 University Avenue West, Waterloo, N2L 3G1, Ontario, Canada

    Frank K. Wilhelm

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Correspondence should be addressed to authors (jclarke@berkeley.edu; fwilhelm@iqc.ca).

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Clarke, J., Wilhelm, F. Superconducting quantum bits. Nature 453, 1031–1042 (2008). https://doi.org/10.1038/nature07128

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