Tomography Archives - IEEE Transactions on Quantum Engineering

SU(4) Gate Design via Unitary Process Tomography: Its Application to Cross-Resonance-Based Superconducting Quantum Devices

July 3, 2025Michihiko Sugawara; Takahiko SatohPhysical ImplementationsCalibration, Coherence time, Logic gates, Qubit, Resonance, Schedules, Superconducting microwave devices, Systematics, Tensors, Tomography

Abstract: In this article, we present a novel approach for implementing pulse-efficient SU(4) gates on cross resonance (CR)-based superconducting quantum devices. Our method introduces a parameterized unitary derived from the CR-Hamiltonian propagator, which accounts for ZZ-interactions. Leveraging the Weyl chamber’s geometric structure, we successfully realize a continuous two-qubit basis gate, RZZ(θ), as an echo-free pulse […]

Model-Predictive Quantum Control via Hamiltonian Learning

November 2, 2022MAISON CLOUÂTRÉOpen Access, Quantum InternetComputational modeling, Control systems, Optimization, Quantum state, Quantum system, Qubit, Tomography

This article proposes an end-to-end framework for the learning-enabled control of closed quantum systems. The proposed learning technique is the first of its kind to utilize a hierarchical design, which layers probing control, quantum state tomography, quantum process tomography, and Hamiltonian learning to identify both the internal and control Hamiltonians. Within this context, a novel […]

New Single-Preparation Methods for Unsupervised Quantum Machine Learning Problems

October 21, 2021Yannick Deville; Alain DevilleOpen Access, Quantum InformationBlind source separation, Machine learning, Parameter estimation, Quantum computing, Quantum state, Random variables, Tomography

The term “machine learning” especially refers to algorithms that derive mappings, i.e., input–output transforms, by using numerical data that provide information about considered transforms. These transforms appear in many problems related to classification/clustering, regression, system identification, system inversion, and input signal restoration/separation. We here analyze the connections between all these problems in the classical and […]