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arXiv · 2109.06616

Complete physical characterization of QND measurements via tomography

L. Pereira·J. J. García-Ripoll·T. Ramos
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Abstract

We introduce a self-consistent tomography for arbitrary quantum non-demolition (QND) detectors. Based on this, we build a complete physical characterization of the detector, including the measurement processes and a quantification of the fidelity, ideality, and back-action of the measurement. This framework is a diagnostic tool for the dynamics of QND detectors, allowing us to identify errors, and to improve their calibration and design. We illustrate this on a realistic Jaynes-Cummings simulation of superconducting qubit readout. We characterize non-dispersive errors, quantify the back-action introduced by the readout cavity, and calibrate the optimal measurement point.

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L. Pereira, J. J. García-Ripoll, T. Ramos. 2021-09-14. Complete physical characterization of QND measurements via tomography. https://doi.org/10.1103/physrevlett.129.010402

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