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Related papers: A Bayesian analysis of classical shadows

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Classical machine learning (ML) provides a potentially powerful approach to solving challenging quantum many-body problems in physics and chemistry. However, the advantages of ML over more traditional methods have not been firmly…

Quantum Physics · Physics 2022-09-28 Hsin-Yuan Huang , Richard Kueng , Giacomo Torlai , Victor V. Albert , John Preskill

We give the first tight sample complexity bounds for shadow tomography and classical shadows in the regime where the target error is below some sufficiently small inverse polynomial in the dimension of the Hilbert space. Formally we give a…

Quantum Physics · Physics 2024-07-22 Sitan Chen , Jerry Li , Allen Liu

Properties of quantum systems can be estimated using classical shadows, which implement measurements based on random ensembles of unitaries. Originally derived for global Clifford unitaries and products of single-qubit Clifford gates,…

Quantum Physics · Physics 2023-09-25 Mirko Arienzo , Markus Heinrich , Ingo Roth , Martin Kliesch

Locally-biased classical shadows allow rapid estimation of energies of quantum Hamiltonians. Recently, derandomised classical shadows have emerged claiming to be even more accurate. This accuracy comes at a cost of introducing classical…

Quantum Physics · Physics 2021-05-27 Charles Hadfield

We introduce a general statistical learning theory for processes that take as input a classical random variable and output a quantum state. Our setting is motivated by the practical situation in which one desires to learn a quantum process…

Quantum Physics · Physics 2025-02-27 Marco Fanizza , Yihui Quek , Matteo Rosati

Classical shadow tomography provides an efficient method for predicting functions of an unknown quantum state from a few measurements of the state. It relies on a unitary channel that efficiently scrambles the quantum information of the…

Quantum Physics · Physics 2022-02-01 Hong-Ye Hu , Yi-Zhuang You

We generalize the classical shadow tomography scheme to a broad class of finite-depth or finite-time local unitary ensembles, known as locally scrambled quantum dynamics, where the unitary ensemble is invariant under local basis…

Quantum Physics · Physics 2025-10-27 Hong-Ye Hu , Soonwon Choi , Yi-Zhuang You

Classical shadow tomography is a sample-efficient technique for characterizing quantum systems and predicting many of their properties. Circuit cutting is a technique for dividing large quantum circuits into smaller fragments that can be…

Quantum Physics · Physics 2024-05-21 Daniel T. Chen , Zain H. Saleem , Michael A. Perlin

An understanding of quantum theory in terms of new, underlying descriptions capable of explaining the existence of non-classical correlations, non-commutativity of measurements and other unique and counter-intuitive phenomena remains still…

Quantum Physics · Physics 2025-05-12 Yasmin Navarrete , Sergio Davis

Quantum algorithms exploiting real-time evolution under a target Hamiltonian have demonstrated remarkable efficiency in extracting key spectral information. However, the broader potential of these methods, particularly beyond ground state…

Many hybrid quantum-classical algorithms for the application of ground state energy estimation in quantum chemistry involve estimating the expectation value of a molecular Hamiltonian with respect to a quantum state through measurements on…

Randomized measurement protocols such as classical shadows represent powerful resources for quantum technologies, with applications ranging from quantum state characterization and process tomography to machine learning and error mitigation.…

Quantum Physics · Physics 2024-06-18 Laurin E. Fischer , Timothée Dao , Ivano Tavernelli , Francesco Tacchino

We introduce a method to enforce some symmetries starting from a trial wave-function prepared on quantum computers that might not respect these symmetries. The technique eliminates the necessity for performing the projection on the quantum…

Quantum Physics · Physics 2023-11-09 Edgar Andres Ruiz Guzman , Denis Lacroix

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

In this article we develop a continuous variable (CV) shadow tomography scheme with wide ranging applications in quantum optics. Our work is motivated by the increasing experimental and technological relevance of CV systems in quantum…

Quantum Physics · Physics 2024-05-03 Simon Becker , Nilanjana Datta , Ludovico Lami , Cambyse Rouzé

Expectation values of observables are routinely estimated using so-called classical shadows$\unicode{x2014}$the outcomes of randomized bases measurements on a repeatedly prepared quantum state. In order to trust the accuracy of shadow…

Quantum Physics · Physics 2025-03-07 Raphael Brieger , Markus Heinrich , Ingo Roth , Martin Kliesch

Bayesian inference is a powerful paradigm for quantum state tomography, treating uncertainty in meaningful and informative ways. Yet the numerical challenges associated with sampling from complex probability distributions hampers Bayesian…

Quantum Physics · Physics 2020-05-04 Joseph M. Lukens , Kody J. H. Law , Ajay Jasra , Pavel Lougovski

Quantum measurements are slow, while classical processors are fast, yet existing hybrid protocols never exploit this asymmetry. In this work, we propose an alternative formulation of classical estimators as online algorithms that are…

Quantum Physics · Physics 2026-03-30 Marwa Marso , Sabrina Herbst , Jadwiga Wilkens , Vincenzo De Maio , Ivona Brandic , Richard Kueng

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

Classifying phase transitions is a fundamental and complex challenge in condensed matter physics. This work proposes a framework for identifying quantum phase transitions by combining classical shadows with unsupervised machine learning. We…