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Related papers: Shadow Tomography of Quantum States

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It is a central fact in quantum mechanics that non-orthogonal states cannot be distinguished perfectly. This property ensures the security of quantum key distribution. It is therefore an important task in quantum communication to design and…

Quantum Physics · Physics 2023-11-27 Lorcan O. Conlon , Falk Eilenberger , Ping Koy Lam , Syed M. Assad

Characterization of quantum states is a fundamental requirement in quantum science and technology. As a promising framework, shadow tomography shows significant efficiency in estimating linear functions, however, for the challenging…

Quantum Physics · Physics 2024-04-19 Xu-Jie Peng , Qing Liu , Lu Liu , Ting Zhang , You Zhou , He Lu

Shadow estimation is an efficient method for predicting many observables of a quantum state with a statistical guarantee. In the multi-shot scenario, one performs projective measurement on the sequentially prepared state for $K$ times after…

Quantum Physics · Physics 2023-07-05 You Zhou , Qing Liu

We provide a new perspective on shadow tomography by demonstrating its deep connections with the general theory of measurement frames. By showing that the formalism of measurement frames offers a natural framework for shadow tomography --…

Quantum state tomography is the task of inferring the state of a quantum system by appropriate measurements. Since the frequency distributions of the outcomes of any finite number of measurements will generally deviate from their asymptotic…

Quantum Physics · Physics 2012-11-08 Matthias Christandl , Renato Renner

We provide the first non-trivial lower bounds for single-qubit tomography algorithms and show that at least ${\Omega}\left(\frac{10^N}{\sqrt{N} \varepsilon^2}\right)$ copies are required to learn an $N$-qubit state…

Quantum Physics · Physics 2025-07-30 Jayadev Acharya , Abhilash Dharmavarapu , Yuhan Liu , Nengkun Yu

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…

Simulating quantum dynamics is one of the most important applications of quantum computers. Traditional approaches for quantum simulation involve preparing the full evolved state of the system and then measuring some physical quantity.…

Quantum Physics · Physics 2025-02-24 Rolando D. Somma , Robbie King , Robin Kothari , Thomas O'Brien , Ryan Babbush

Learning properties of quantum states from measurement data is a fundamental challenge in quantum information. The sample complexity of such tasks depends crucially on the measurement primitive. While shadow tomography achieves…

Quantum Physics · Physics 2025-10-10 Jan Nöller , Viet T. Tran , Mariami Gachechiladze , Richard Kueng

We explore the possibility of using "weak" measurements to carry out quantum state tomography. Given a certain fixed number of copies of identically prepared states of a qubit, we simulate state tomography using weak as well as projective…

Quantum Physics · Physics 2014-08-06 Debmalya Das , Arvind

We extend quantum state tomography with minimal cumulative disturbance, first investigated in [arXiv:2406.18370], to arbitrary finite-dimensional pure states. A learner sequentially receives fresh copies of an unknown pure state, chooses a…

Quantum Physics · Physics 2026-05-12 Josep Lumbreras , Marco Tomamichel

We introduce Sketch Tomography, an efficient procedure for quantum state tomography based on the classical shadow protocol used for quantum observable estimations. The procedure applies to the case where the ground truth quantum state is a…

Quantum Physics · Physics 2026-05-27 Xun Tang , Haoxuan Chen , Yuehaw Khoo , Lexing Ying

In quantum information theory, the accurate estimation of observables is pivotal for quantum information processing, playing a crucial role in compute and communication protocols. This work introduces a novel technique for estimating such…

Quantum Physics · Physics 2024-09-17 Andrea Caprotti , Joshua Morris , Borivoje Dakić

Measuring properties of quantum systems is a fundamental problem in quantum mechanics. We provide a simple method for estimating the expectation value of observables with an unknown quantum state. The idea is to use a data structure to…

Quantum Physics · Physics 2024-03-25 Naixu Guo , Feng Pan , Patrick Rebentrost

To improve the efficiency of the state tomography strategy via weak value, we have searched the optimal coupling strength between the system and measuring device. For an arbitrary d-dimensional quantum system, the optimal strengths being…

Quantum Physics · Physics 2024-02-23 Xuanmin Zhu , Dezheng Zhang , Runping Gao , Qun wei , Lixia Liu , Zijiang Luo

In this article, we introduce a framework for quantum state tomography of qutrits by projective measurements. The framework is based on photon-counting with measurement results distorted due to the Poisson noise and dark counts. Two…

Quantum Physics · Physics 2021-10-26 Jakub Szlachetka , Artur Czerwinski

Quantum state tomography is the fundamental physical task of learning a complete classical description of an unknown state of a quantum system given coherent access to many identical samples of it. The complexity of this task is commonly…

Quantum Physics · Physics 2026-05-25 Yanglin Hu , Enrique Cervero-Martín , Elias Theil , Laura Mančinska , Marco Tomamichel

Quantum state tomography, a fundamental tool for quantum physics, usually requires a number of state copies that scale exponentially with the system size, owing to the intricate quantum correlations between subsystems. We show that, in…

Quantum Physics · Physics 2025-12-22 Xiaobin Zhao , Pengcheng Liao , Francesco Anna Mele , Ulysse Chabaud , Quntao Zhuang

Entanglement, one of the central mysteries of quantum mechanics, plays an essential role in numerous applications of quantum information theory. A natural question of both theoretical and experimental importance is whether universal…

Although the realization of useful quantum computers poses significant challenges, swift progress in emerging quantum technologies is making this goal realistically approachable. In this context, one of the essential resources is quantum…

Quantum Physics · Physics 2022-01-11 Valeria Saggio , Philip Walther
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