Machine learning (ML) has emerged as a formidable force for identifying hidden but
pertinent patterns within a given data set with the objective of subsequent generation of …

Gate set tomography (GST) is a protocol for detailed, predictive characterization of logic
operations (gates) on quantum computing processors. Early versions of GST emerged …

Linear optics underpins fundamental tests of quantum mechanics and quantum
technologies. We demonstrate a single reprogrammable optical circuit that is sufficient to …

We use quantum detector tomography to characterize the qubit readout in terms of
measurement positive operator-valued measures (POVMs) on IBM quantum computers IBM …

Intuitively, if a density operator has small rank, then it should be easier to estimate from
experimental data, since in this case only a few eigenvectors need to be learned. We prove …

Quantum process tomography is a powerful tool for understanding quantum channels and
characterizing the properties of quantum devices. Inspired by recent advances using …

Quantum process tomography is a necessary tool for verifying quantum gates and
diagnosing faults in architectures and gate design. We show that the standard approach of …

We provide an efficient method for computing the maximum-likelihood mixed quantum state
(with density matrix ρ) given a set of measurement outcomes in a complete orthonormal …

Quantum coherence is a fundamental property of quantum systems, separating quantum
from classical physics. Recently, there has been significant interest in the characterization of …