Variable electrostatic transformer: controllable coupling of two charge qubits

D. V. Averin; C. Bruder

doi:10.1103/physrevlett.91.057003

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Variable electrostatic transformer: controllable coupling of two charge qubits

D. V. Averin·C. Bruder

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Abstract

We propose and investigate a novel method for the controlled coupling of two Josephson charge qubits by means of a variable electrostatic transformer. The value of the coupling capacitance is given by the discretized curvature of the lowest energy band of a Josephson junction, which can be positive, negative, or zero. We calculate the charging diagram of the two-qubit system that reflects the transition from positive to negative through vanishing coupling. We also discuss how to construct a phase gate making use of the controllable coupling.

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D. V. Averin, C. Bruder. 2003-07-28. Variable electrostatic transformer: controllable coupling of two charge qubits. https://doi.org/10.1103/physrevlett.91.057003

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