Parallel tomography of quantum non-demolition measurements in multi-qubit devices
Abstract
An efficient characterization of QND measurements is an important ingredient towards certifying and improving the performance and scalability of quantum processors. In this work, we introduce a parallel tomography of QND measurements that addresses single- and two-qubit readout on a multi-qubit quantum processor. We provide an experimental demonstration of the tomographic protocol on a 7-qubit IBM-Q device, characterizing the quality of conventional qubit readout as well as generalized measurements such as parity or measurement-and-reset schemes. Our protocol reconstructs the Choi matrices of the measurement processes, extracts relevant quantifiers -- fidelity, QND-ness, destructiveness -- and identifies sources of errors that limit the performance of the device for repeated QND measurements. We also show how to quantify measurement cross-talk and use it to certify the quality of simultaneous readout on multiple qubits.
Keywords
Cite
@article{arxiv.2204.10336,
title = {Parallel tomography of quantum non-demolition measurements in multi-qubit devices},
author = {L. Pereira and J. J. García-Ripoll and T. Ramos},
journal= {arXiv preprint arXiv:2204.10336},
year = {2023}
}