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⟩ 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.
@article{arxiv.1006.5084,
title = {Quantum process tomography of two-qubit controlled-Z and controlled-NOT gates using superconducting phase qubits},
author = {T. Yamamoto and M. Neeley and E. Lucero and R. C. Bialczak and J. Kelly and M. Lenander and Matteo Mariantoni and A. D. O'Connell and D. Sank and H. Wang and M. Weides and J. Wenner and Y. Yin and A. N. Cleland and John M. Martinis},
journal= {arXiv preprint arXiv:1006.5084},
year = {2013}
}
Comments
10 pages, 8 figures, including supplementary information