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Related papers: Optimising quantum tomography via shadow inversion

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Classical machine learning theory and theory of quantum computations are among of the most rapidly developing scientific areas in our days. In recent years, researchers investigated if quantum computing can help to improve classical machine…

Quantum Physics · Physics 2019-06-26 D. V. Fastovets , Yu. I. Bogdanov , B. I. Bantysh , V. F. Lukichev

Shadow tomography protocols have recently emerged as powerful tools for efficient quantum state learning, aiming to reconstruct expectation values of observables with fewer resources than traditional quantum state tomography. For the…

Quantum Physics · Physics 2026-01-27 Viet T. Tran , Richard Kueng

With nowadays steadily growing quantum processors, it is required to develop new quantum tomography tools that are tailored for high-dimensional systems. In this work, we describe such a computational tool, based on recent ideas from…

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

The classification of quantum phases of matter remains a fundamental challenge in condensed matter physics. We present a novel framework that combines shadow tomography with modern time-series machine learning models to enable efficient and…

Quantum Physics · Physics 2025-08-08 Weicheng Ye , Shuwei Liu , Shiyu Zhou , Yijian Zou

Adaptive measurements were recently shown to significantly improve the performance of quantum state tomography. Utilizing information about the system for the on-line choice of optimal measurements allows to reach the ultimate bounds of…

Quantum scale estimation, as introduced and explored here, establishes the most precise framework for the estimation of scale parameters that is allowed by the laws of quantum mechanics. This addresses an important gap in quantum metrology,…

Quantum Physics · Physics 2022-11-18 Jesús Rubio

Quantum illumination consists in shining quantum light on a target region immersed in a bright thermal bath, with the aim of detecting the presence of a possible low-reflective object. If the signal is entangled with the receiver, then a…

Quantum Physics · Physics 2017-02-28 M. Sanz , U. Las Heras , J. J. Garcia-Ripoll , E. Solano , R. Di Candia

Circuit optimization is a fundamental task for practical applications of near-term quantum computers. In this work we address this challenge through the powerful lenses of tensor network theory. Our approach involves the full…

Quantum Physics · Physics 2024-10-29 Matan Ben-Dov , Itai Arad , Emanuele G. Dalla Torre

In modelling complex processes, the potential past data that influence future expectations are immense. Models that track all this data are not only computationally wasteful but also shed little light on what past data most influence the…

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

Because of the constraint that the estimators be bona fide physical states, any quantum state tomography scheme - including the widely used maximum likelihood estimation - yields estimators that may have a bias, although they are consistent…

Quantum Physics · Physics 2014-05-22 Jiangwei Shang , Hui Khoon Ng , Berthold-Georg Englert

Efficiently estimating the quantum Fisher information (QFI) is pivotal in quantum information science but remains an outstanding challenge for large systems due to its high nonlinearity. In this Letter, we tackle this long-standing…

Quantum Physics · Physics 2025-03-21 Da-Jian Zhang , D. M. Tong

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

Classical shadows (CS) have emerged as a powerful way to estimate many properties of quantum states based on random measurements and classical post-processing. In their original formulation, they come with optimal (or close to) sampling…

Quantum Physics · Physics 2024-08-13 Frederic Sauvage , Martin Larocca

High precision measurements are essential to solve major scientific and technological challenges, from gravitational wave detection to healthcare diagnostics. Quantum sensing delivers greater precision, but an in-depth optimisation of…

We propose a resource-efficient shadow-tomography scheme using equatorial-stabilizer measurements generated from subsets of Clifford unitaries. For $n$-qubit systems, equatorial-stabilizer-based shadow-tomography schemes can estimate $M$…

Quantum Physics · Physics 2025-08-01 Guedong Park , Yong Siah Teo , Hyunseok Jeong

We provide a new quantum algorithm that efficiently determines the quality of a least-squares fit over an exponentially large data set by building upon an algorithm for solving systems of linear equations efficiently (Harrow et al., Phys.…

Quantum Physics · Physics 2013-01-10 Nathan Wiebe , Daniel Braun , Seth Lloyd

Projective measurements with high quantum efficiency is often assumed to be required for efficient circuit based quantum computing. We argue that this is not the case and show that this fact has actually be known previously though not…

Quantum Physics · Physics 2015-03-17 A. P. Lund

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