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Related papers: Learning shadows to predict quantum ground state c…

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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

We introduce a new approach to learn Hamiltonians through a resource that we call the pseudo-Choi state, which encodes the Hamiltonian in a state using a procedure that is analogous to the Choi-Jamiolkowski isomorphism. We provide an…

Quantum Physics · Physics 2025-04-16 Juan Castaneda , Nathan Wiebe

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…

A crucial subroutine for various quantum computing and communication algorithms is to efficiently extract different classical properties of quantum states. In a notable recent theoretical work by Huang, Kueng, and Preskill [Nat. Phys. 16,…

Quantum Physics · Physics 2021-11-19 Ting Zhang , Jinzhao Sun , Xiao-Xu Fang , Xiao-Ming Zhang , Xiao Yuan , He Lu

Projective measurements of collective observables can be employed to herald the preparation of entangled states of quantum systems, and the resulting conditional dynamics is usually handled by stochastic master equation (SME) for small…

Quantum Physics · Physics 2026-02-13 ZhiQing Zhang , HaiZhong Guo , Lingrui Wang , Gang Chen , Chongxin Shan , Klaus Mølmer , Yuan Zhang

We investigate an approach for studying the ground state of a quantum many-body Hamiltonian that is based on treating the correlation functions as variational parameters. In this approach, the challenge set by the exponentially-large…

Strongly Correlated Electrons · Physics 2020-01-22 Arbel Haim , Richard Kueng , Gil Refael

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

We introduce a sum-of-squares SDP hierarchy approximating the ground-state energy from below for quantum many-body problems, with a natural quantum embedding interpretation. We establish the connections between our approach and other…

Quantum Physics · Physics 2023-05-31 Bowen Li , Jianfeng Lu

Quantum state tomography is a key process in most quantum experiments. In this work, we employ quantum machine learning for state tomography. Given an unknown quantum state, it can be learned by maximizing the fidelity between the output of…

The ability to efficiently characterize the spatial correlations of entangled states of light is critical for applications of many quantum technologies such as quantum imaging. Here, we demonstrate highly efficient theoretical and…

Quantum Physics · Physics 2024-10-08 Mahtab Amooei , Girish Kulkarni , Jeremy Upham , Robert W. Boyd

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

We develop a classical shadow tomography protocol utilizing the randomized measurement scheme based on hybrid quantum circuits, which consist of layers of two-qubit random unitary gates mixed with single-qubit random projective…

Quantum Physics · Physics 2023-09-26 Ahmed A. Akhtar , Hong-Ye Hu , Yi-Zhuang You

Randomized measurement protocols, including classical shadows, entanglement tomography, and randomized benchmarking are powerful techniques to estimate observables, perform state tomography, or extract the entanglement properties of quantum…

Quantum Physics · Physics 2024-04-03 Jacob Bringewatt , Jonathan Kunjummen , Niklas Mueller

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

Efficiently learning expectation values of a quantum state using classical shadow tomography has become a fundamental task in quantum information theory. In a classical shadows protocol, one measures a state in a chosen basis W after it has…

Quantum Physics · Physics 2025-06-04 Maxwell West , Antonio Anna Mele , Martin Larocca , M. Cerezo

Measuring expectation values of observables is an essential ingredient in variational quantum algorithms. A practical obstacle is the necessity of a large number of measurements for statistical convergence to meet requirements of precision,…

Quantum Physics · Physics 2022-09-07 Masaya Kohda , Ryosuke Imai , Keita Kanno , Kosuke Mitarai , Wataru Mizukami , Yuya O. Nakagawa

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

It is believed that one of the first useful applications for a quantum computer will be the preparation of groundstates of molecular Hamiltonians. A crucial task involving state preparation and readout is obtaining physical observables of…

Quantum state tomography is a fundamental task in quantum information science, enabling detailed characterization of correlations, entanglement, and electronic structure in quantum systems. However, its exponential measurement and…

The coherent superposition of non-orthogonal fermionic Gaussian states has been shown to be an efficient approximation to the ground states of quantum impurity problems [Bravyi and Gosset,Comm. Math. Phys.,356 451 (2017)]. We present a…

Strongly Correlated Electrons · Physics 2021-09-01 Samuel Boutin , Bela Bauer