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Related papers: Logical shadow tomography: Efficient estimation of…

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Shadow tomography aims to build a classical description of a quantum state from a sequence of simple random measurements. Physical observables are then reconstructed from the resulting classical shadow. Shadow protocols which use…

Quantum Physics · Physics 2024-08-14 Sumner N. Hearth , Michael O. Flynn , Anushya Chandran , Chris R. Laumann

Recent progress in fault-tolerant quantum computing suggests that leveraging error-syndrome information at the logical layer can substantially improve performance, including the estimation of logical observables from noisy states. In this…

Quantum Physics · Physics 2026-03-06 Kento Tsubouchi , Hyukgun Kwon , Liang Jiang , Nobuyuki Yoshioka

Classical shadow tomography is a powerful randomized measurement protocol for predicting many properties of a quantum state with few measurements. Two classical shadow protocols have been extensively studied in the literature: the…

Quantum Physics · Physics 2023-06-07 Ahmed A. Akhtar , Hong-Ye Hu , Yi-Zhuang You

The rapid advancement of quantum computing has led to an extensive demand for effective techniques to extract classical information from quantum systems, particularly in fields like quantum machine learning and quantum chemistry. However,…

Quantum Physics · Physics 2023-05-09 Yifei Chen , Zhan Yu , Chenghong Zhu , Xin Wang

Learning quantum state properties is both a fundamental and practical problem in quantum information theory. Classical shadows have emerged as an efficient method for estimating properties of unknown quantum states, with rigorous…

Quantum Physics · Physics 2026-03-30 Hugo Thomas , Ulysse Chabaud , Pierre-Emmanuel Emeriau

Classical shadows are a powerful method for learning many properties of quantum states in a sample-efficient manner, by making use of randomized measurements. Here we study the sample complexity of learning the expectation value of Pauli…

Quantum Physics · Physics 2023-06-13 Matteo Ippoliti , Yaodong Li , Tibor Rakovszky , Vedika Khemani

We combine classical heuristics with partial shadow tomography to enable efficient protocols for extracting information from correlated ab initio electronic systems encoded on quantum devices. By proposing the use of a correlation energy…

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 investigate the advantages of using autoregressive neural quantum states as ansatze for classical shadow tomography to improve its predictive power. We introduce a novel estimator for optimizing the cross-entropy loss function using…

Quantum Physics · Physics 2024-08-23 Wirawat Kokaew , Bohdan Kulchytskyy , Shunji Matsuura , Pooya Ronagh

Measuring global quantum properties-such as the fidelity to complex multipartite states-is both an essential and experimentally challenging task. Classical shadow estimation offers favorable sample complexity, but typically relies on…

Quantum Physics · Physics 2026-02-11 Qingyue Zhang , Dayue Qin , Zhou You , Feng Xu , Jens Eisert , You Zhou

We provide a polynomial-time classical algorithm for noisy quantum circuits. The algorithm computes the expectation value of any observable for any circuit, with a small average error over input states drawn from an ensemble (e.g. the…

Quantum Physics · Physics 2024-10-15 Thomas Schuster , Chao Yin , Xun Gao , Norman Y. Yao

Classical shadows are an efficient method for constructing an approximate classical description of a quantum state using very few measurements. In the paper we propose to enhance classical shadow methods using bootstrap resampling methods.…

Quantum Physics · Physics 2025-11-18 Eric Ghysels , Jack Morgan

Estimating observable expectation values in eigenstates of quantum systems has a broad range of applications and is an area where early fault-tolerant quantum computers may provide practical quantum advantage. We develop a hybrid…

Quantum Physics · Physics 2026-03-03 Bence Bakó , Tenzan Araki , Bálint Koczor

Quantum computation, a completely different paradigm of computing, benefits from theoretically proven speed-ups for certain problems and opens up the possibility of exactly studying the properties of quantum systems. Yet, because of the…

We provide practical and powerful schemes for learning many properties of an unknown n-qubit quantum state using a sparing number of copies of the state. Specifically, we present a depth-modulated randomized measurement scheme that…

Recently introduced shadow tomography protocols use classical shadows of quantum states to predict many target functions of an unknown quantum state. Unlike full quantum state tomography, shadow tomography does not insist on accurate…

Quantum Physics · Physics 2021-05-27 Atithi Acharya , Siddhartha Saha , Anirvan M. Sengupta

Accurately estimating expectation values of quantum observables with as few measurements as possible is crucial to many quantum computing applications. We introduce a framework that covers many of existing measurement strategies and…

Accurately estimating the properties of quantum systems is a central challenge in quantum computing and quantum information. We propose a method to obtain unbiased estimators of multiple observables with low statistical error by…

Quantum Physics · Physics 2025-07-25 Stefano Mangini , Daniel Cavalcanti

The classical shadow estimation protocol is a noise-resilient and sample-efficient quantum algorithm for learning the properties of quantum systems. Its performance depends on the choice of a unitary ensemble, which must be chosen by a user…

Quantum Physics · Physics 2024-01-10 Kaifeng Bu , Dax Enshan Koh , Roy J. Garcia , Arthur Jaffe

Classical verification of quantum learning allows classical clients to reliably leverage quantum computing advantages by interacting with untrusted quantum servers. Yet, current quantum devices available in practice suffers from a variety…

Quantum Physics · Physics 2024-11-15 Yinghao Ma , Jiaxi Su , Dong-Ling Deng