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Measuring Controlled-NOT and two-qubit gate operation

Andrew G. White·Alexei Gilchrist·Geoffrey J. Pryde·Jeremy L. O'Brien·Michael J. Bremner·Nathan K. Langford
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Abstract

Accurate characterisation of two-qubit gates will be critical for any realisation of quantum computation. We discuss a range of measurements aimed at characterising a two-qubit gate, specifically the CNOT gate. These measurements are architecture-independent, and range from simple truth table measurements, to single figure measures such as the fringe visibility, parity, fidelity, and entanglement witnesses, through to whole-state and whole-gate measures achieved respectively via quantum state and process tomography. In doing so, we examine critical differences between classical and quantum gate operation.

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Andrew G. White, Alexei Gilchrist, Geoffrey J. Pryde, Jeremy L. O'Brien, Michael J. Bremner, Nathan K. Langford. 2003-08-22. Measuring Controlled-NOT and two-qubit gate operation. https://doi.org/10.1364/josab.24.000172

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