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Related papers: Optimal Quantum State Tomography with Noisy Gates

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Quantum state tomography aims to estimate the state of a quantum mechanical system which is described by a trace one, Hermitian positive semidefinite complex matrix, given a set of measurements of the state. Existing works focus on…

Quantum Physics · Physics 2023-03-22 Siva Shanmugam , Sheetal Kalyani

We introduce and demonstrate experimentally: (1) a framework called "gate set tomography" (GST) for self-consistently characterizing an entire set of quantum logic gates on a black-box quantum device; (2) an explicit closed-form protocol…

The impressive pace of advance of quantum technology calls for robust and scalable techniques for the characterization and validation of quantum hardware. Quantum process tomography, the reconstruction of an unknown quantum channel from…

The presence of noise in quantum computers hinders their effective operation. Even though quantum error correction can theoretically remedy this problem, its practical realization is still a challenge. Testing and benchmarking noisy,…

Quantum Physics · Physics 2023-02-15 Adrian Ortega , Orsolya Kálmán , Tamás Kiss

Characterizing the noise in the set of gate operations that form the building blocks of a quantum computational device is a necessity for assessing the quality of the device. Here, we introduce randomized linear gate set tomography, an…

Quantum Physics · Physics 2021-08-25 Yanwu Gu , Rajesh Mishra , Berthold-Georg Englert , Hui Khoon Ng

Quantum process tomography (QPT) plays a central role in characterizing quantum gates and circuits, diagnosing quantum devices, calibrating hardware, and supporting quantum error correction. However, conventional QPT methods face challenges…

Quantum Physics · Physics 2026-02-06 Huynh Le Dan Linh , Vu Tuan Hai , Le Bin Ho

Quantum state tomography (QST) is a widely employed technique for characterizing the state of a quantum system. However, it is plagued by two fundamental challenges: computational and experimental complexity grows exponentially with the…

Quantum Physics · Physics 2025-11-12 Akshay Gaikwad , Manuel Sebastian Torres , Shahnawaz Ahmed , Anton Frisk Kockum

Quantum state tomography is a fundamental tool in quantum information processing. It allows us to estimate the state of a quantum system by measuring different observables on many identically prepared copies of the system. This is, in…

Quantum Physics · Physics 2011-11-28 Carlos A. Riofrío

Quantum computation represents a promising frontier in the domain of high-performance computing, blending quantum information theory with practical applications to overcome the limitations of classical computation. This study investigates…

Quantum Physics · Physics 2025-01-23 King Yiu Yu , Aritra Sarkar , Maximilian Rimbach-Russ , Ryoichi Ishihara , Sebastian Feld

Engineering quantum devices requires reliable characterization of the quantum system, including qubits, quantum operations (also known as instruments) and the quantum noise. Recently, quantum gate set tomography (GST) has emerged as a…

Quantum Physics · Physics 2024-04-16 Ze-Tong Li , Cong-Cong Zheng , Fan-Xu Meng , Han Zeng , Tian Luan , Zai-Chen Zhang , Xu-Tao Yu

Quantum Process Tomography (QPT) methods aim at identifying, i.e. estimating, a quantum process. QPT is a major quantum information processing tool, since it especially allows one to experimentally characterize the actual behavior of…

Quantum Physics · Physics 2025-06-27 Yannick Deville , Alain Deville

Quantum machine learning offers promising advantages for classification tasks, but noise, decoherence, and connectivity constraints in current devices continue to limit the efficient execution of feature map-based circuits. Gate Assessment…

Machine Learning · Computer Science 2026-03-23 F. Rodríguez-Díaz , D. Gutiérrez-Avilés , A. Troncoso , F. Martínez-Álvarez

Quantum state tomography (QST) is a fundamental technique for estimating the state of a quantum system from measured data and plays a crucial role in evaluating the performance of quantum devices. However, standard estimation methods become…

Quantum Physics · Physics 2026-01-27 Shakir Showkat Sofi , Charlotte Vermeylen , Lieven De Lathauwer

We present a framework that formulates the quest for the most efficient quantum state tomography scheme as an optimization problem which can be solved numerically. This approach can be applied to a broad spectrum of relevant setups…

Quantum Physics · Physics 2021-12-17 Violeta N. Ivanova-Rohling , Guido Burkard , Niklas Rohling

Quantum computation has been growing rapidly in both theory and experiments. In particular, quantum computing devices with a large number of qubits have been developed by IBM, Google, IonQ, and others. The current quantum computing devices…

Quantum Physics · Physics 2021-02-10 Rishabh Gupta , Rongxin Xia , Raphael D. Levine , Sabre Kais

Quantum state tomography (QST) is a crucial tool for characterizing quantum states. However, QST becomes impractical for reconstructing multi-qubit density matrices since data sets and computational costs grow exponentially with qubit…

Quantum Physics · Physics 2026-04-02 Aniket Patel , Akshay Gaikwad , Tangyou Huang , Anton Frisk Kockum , Tahereh Abad

Quantum state tomography (QST) is the procedure for reconstructing unknown quantum states from a series of measurements of different observables. Depending on the physical system, different sets of observables have been used for this…

Quantum Physics · Physics 2023-03-02 Jingfu Zhang , Swathi S. Hegde , Dieter Suter

Quantum state tomography (QST) is plagued by the ``curse of dimensionality'' due to the exponentially-scaled complexity in measurement and data post-processing. Efficient QST schemes for large-scale mixed states are currently missing. In…

Quantum Physics · Physics 2023-08-15 Wen-jun Li , Kai Xu , Heng Fan , Shi-ju Ran , Gang Su

We present two scalable and entanglement-free methods for estimating the collective state of an n-qubit quantum computer. The first method consists of a fixed set of five quantum circuits-regardless of the number of qubits-that avoid the…

Quantum system characterization techniques represent the front line in the identification and mitigation of noise in quantum computing, but can be expensive in terms of quantum resources and time to repeatedly employ. Another challenging…

Quantum Physics · Physics 2021-01-20 Gregory A. L. White , Charles D. Hill , Lloyd C. L. Hollenberg