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arXiv · 1006.5084

Quantum process tomography of two-qubit controlled-Z and controlled-NOT gates using superconducting phase qubits

T. Yamamoto·M. Neeley·E. Lucero·R. C. Bialczak·J. Kelly·M. Lenander·Matteo Mariantoni·A. D. O'Connell·D. Sank·H. Wang·M. Weides·J. Wenner·Y. Yin·A. N. Cleland·John M. Martinis
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Abstract

We experimentally demonstrate quantum process tomography of controlled-Z and controlled-NOT gates using capacitively-coupled superconducting phase qubits. These gates are realized by using the $|2\rangle$ state of the phase qubit. We obtain a process fidelity of 0.70 for the controlled-phase and 0.56 for the controlled-NOT gate, with the loss of fidelity mostly due to single-qubit decoherence. The controlled-Z gate is also used to demonstrate a two-qubit Deutsch-Jozsa algorithm with a single function query.

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T. Yamamoto, M. Neeley, E. Lucero, R. C. Bialczak, J. Kelly, M. Lenander, Matteo Mariantoni, A. D. O'Connell, D. Sank, H. Wang, M. Weides, J. Wenner, Y. Yin, A. N. Cleland, John M. Martinis. 2010-06-25. Quantum process tomography of two-qubit controlled-Z and controlled-NOT gates using superconducting phase qubits. https://doi.org/10.1103/physrevb.82.184515

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