Initialization by measurement of a two-qubit superconducting circuit

2012/04/11 by D. Ristè, J. G. van Leeuwen, H. -S. Ku +2 · 1 citation
Physics and Astronomy · #cond-mat.mes-hall #quant-ph

paper · pdf · doi:10.1103/physrevlett.109.050507

published as Phys. Rev. Lett. 109, 050507 (2012) · 5 pages, 4 figures, and Supplementary Information (7 figures, 1 table)

arxiv created 2012/04/11 · arxiv updated 2012/08/07

Abstract

We demonstrate initialization by joint measurement of two transmon qubits in 3D circuit quantum electrodynamics. Homodyne detection of cavity transmission is enhanced by Josephson parametric amplification to discriminate the two-qubit ground state from single-qubit excitations non-destructively and with 98.1% fidelity. Measurement and postselection of a steady-state mixture with 4.7% residual excitation per qubit achieve 98.8% fidelity to the ground state, thus outperforming passive initialization.

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• Blind Quantum Computation on a Modular Superconducting Processor

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