Maximal Entropy Approach for Quantum State Tomography

Quantum computation has been growing rapidly in both theory and experiments. In particular, quantum computing devices with a large number of qubits have developed by IBM, Google, IonQ, others. The current are noisy intermediate-scale devices, so approaches to validate processing on these needed. One the most common ways validation for an n-qubit system is tomography, which tries reconstruct system’s density matrix complete set observables. However, inherent noise systems intrinsic limitations pose critical challenge precisely know actual measurement operators that make tomography impractical Here, we propose alternative approach based maximal information entropy, can predict values unknown observables available mean data. This then be used high fidelity even though results some missing. Of additional contexts, practical inference mechanical state using only partial also needed.1 MoreReceived 31 August 2020Accepted 24 December 2020DOI:https://doi.org/10.1103/PRXQuantum.2.010318Published American Physical Society under terms Creative Commons Attribution 4.0 International license. Further distribution this work must maintain attribution author(s) published article's title, journal citation, DOI.Published SocietyPhysics Subject Headings (PhySH)Research AreasMeasurement-based computingQuantum computationQuantum processingQuantum simulationQuantum tomographyQuantum Information