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Related papers: Lindblad Tomography of a Superconducting Quantum P…

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We revisit the problem of fitting Lindbladian models to the outputs of quantum process tomography. A sequence of prior theoretical works approached the problem by considering whether there exists a Lindbladian generator close to a matrix…

Quantum Physics · Physics 2025-07-11 Yinchen Liu , James R. Seddon , Tamara Kohler , Emilio Onorati , Toby S. Cubitt

High-fidelity mid-circuit measurements, which read out the state of specific qubits in a multiqubit processor without destroying them or disrupting their neighbors, are a critical component for useful quantum computing. They enable…

Quantum Physics · Physics 2024-10-23 Daniel Hothem , Jordan Hines , Charles Baldwin , Dan Gresh , Robin Blume-Kohout , Timothy Proctor

We propose simple protocols for performing quantum noise spectroscopy based on the method of transfer tensor maps (TTM), [Phys. Rev. Lett. 112, 110401 (2014)]. The TTM approach is a systematic way to deduce the memory kernel of a…

Quantum Physics · Physics 2019-05-29 Yu-Qin Chen , Kai-Li Ma , Yi-Cong Zheng , Jonathan Allcock , Shengyu Zhang , Chang-Yu Hsieh

Designing quantum systems with the measurement speed and accuracy needed for quantum error correction using superconducting qubits requires iterative design and test informed by accurate models and characterization tools. We introduce a…

For an initially well designed but imperfect quantum information system, the process matrix is almost sparse in an appropriate basis. Existing theory and associated computational methods (L1-norm minimization) for reconstructing sparse…

Quantum Physics · Physics 2009-03-06 Robert L. Kosut

Characterization of quantum processes is a preliminary step necessary in the development of quantum technology. The conventional method uses standard quantum process tomography, which requires $d^2$ input states and $d^4$ quantum…

Quantum Physics · Physics 2020-02-26 Zhibo Hou , Jun-Feng Tang , Christopher Ferrie , Guo-Yong Xiang , Chuan-Feng Li , Guang-Can Guo

Accurate and robust estimation of quantum process properties is crucial for quantum information processing and quantum many-body physics. Combining classical shadow tomography and randomized benchmarking, Helsen et al. introduced a method…

Quantum Physics · Physics 2024-12-02 Yuqing Wang , Guoding Liu , Zhenhuan Liu , Yifan Tang , Xiongfeng Ma , Hao Dai

Scalable realisation of quantum computing is reliant on the development of fault tolerant devices. Analysis of quantum error correction protocols typically considers incoherent noise models or noise-free syndrome measurements. While this is…

Quantum Physics · Physics 2026-05-29 Ben Harper , Azar C. Nakhl , Martin Sevior , Muhammad Usman

Quantum computing testbeds exhibit high-fidelity quantum control over small collections of qubits, enabling performance of precise, repeatable operations followed by measurements. Currently, these noisy intermediate-scale devices can…

We develop techniques to probe the dynamics of quantum information, and implement them experimentally on an IBM superconducting quantum processor. Our protocols adapt shadow tomography for the study of time evolution channels rather than of…

Quantum Physics · Physics 2022-08-09 Max McGinley , Sebastian Leontica , Samuel J. Garratt , Jovan Jovanovic , Steven H. Simon

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 process tomography is grossly inaccurate in the case where the states…

Extracting information efficiently from quantum systems is a major component of quantum information processing tasks. Randomized measurements, or classical shadows, enable predicting many properties of arbitrary quantum states using few…

We present a method for characterizing the performance of noisy quantum processors using discrete time crystals. Deviations from ideal persistent oscillatory behavior give rise to numerical scores by which relative quantum processor…

Quantum Physics · Physics 2023-01-19 Victoria Zhang , Paul D. Nation

As far as we know, a useful quantum computer will require fault-tolerant gates, and existing schemes demand a prohibitively large space and time overhead. We argue that a first generation quantum computer will be very valuable to design,…

Quantum Physics · Physics 2017-11-15 Pavithran S. Iyer , David Poulin

There has been tremendous progress in the physical realization of quantum computing hardware in recent times, bringing us closer than ever before to realizing the promise of quantum computing. However, noise continues to pose a crucial…

The temporal evolution of a quantum system can be characterized by quantum process tomography, a complex task that consumes a number of physical resources scaling exponentially with the number of subsystems. An alternative approach to the…

Quantum process tomography is a critical task for characterizing the dynamics of quantum systems and achieving precise quantum control. In this paper, we propose a two-stage solution for both trace-preserving and non-trace-preserving…

Quantum computers promise to solve certain problems more efficiently than their digital counterparts. A major challenge towards practically useful quantum computing is characterizing and reducing the various errors that accumulate during an…

In this article, we introduce a framework for Hamiltonian tomography of multi-qubit systems with random noise. We adopt the quantum quench protocol to reconstruct a many-body Hamiltonian by local measurements that are distorted by random…

Quantum Physics · Physics 2021-11-30 Artur Czerwinski

Quantum simulation, the study of strongly correlated quantum matter using synthetic quantum systems, has been the most successful application of quantum computers to date. It often requires determining observables with high precision, for…