English
Related papers

Related papers: Quantum measurement fitting

200 papers

We consider the problem of determining the weights of a quantum ensemble. That is to say, given a quantum system that is in a set of possible known states according to an unknown probability law, we give strategies to estimate the…

Quantum Physics · Physics 2010-02-01 J. I. de Vicente , J. Calsamiglia , R. Munoz-Tapia , E. Bagan

Reliable uncertainty quantification (UQ) in machine learning (ML) regression tasks is becoming the focus of many studies in materials and chemical science. It is now well understood that average calibration is insufficient, and most studies…

Machine Learning · Statistics 2024-01-25 Pascal Pernot

In quantum theory, it is known for a pair of noncommutative observables that there is no state on which they take simultaneously definite values, and that there is no joint measurement of them. They are called preparation uncertainty and…

Quantum Physics · Physics 2020-09-02 Ryo Takakura , Takayuki Miyadera

Axiomatic approach to measurement theory is developed. All the possible statistical properties of apparatuses measuring an observable with nondegenerate spectrum allowed in standard quantum mechanics are characterized.

Quantum Physics · Physics 2007-05-23 Masanao Ozawa

A new measure of information in quantum mechanics is proposed which takes into account that for quantum systems the only feature known before an experiment is performed are the probabilities for various events to occur. The sum of the…

Quantum Physics · Physics 2009-11-06 Caslav Brukner , Anton Zeilinger

While quantum speed-up in solving certain decision problems by a fault-tolerant universal quantum computer has been promised, a timely research interest includes how far one can reduce the resource requirement to demonstrate a provable…

Quantum Physics · Physics 2018-01-01 Jacob Miller , Stephen Sanders , Akimasa Miyake

Two of the most common interpretations of quantum measurement disagree about the fate of quantum amplitudes after measurement, yet this disagreement has not previously led to experimentally distinguishable predictions. In the standard…

Quantum Physics · Physics 2026-03-17 Christoph Adami , Lambert Giner , Jeff S. Lundeen , Raphael A. Abrahao

Quantum measurements are our eyes to the quantum systems consisting of a multitude of microscopic degrees of freedom. However, the intrinsic uncertainty of quantum measurements and the exponentially large Hilbert space pose natural barriers…

Strongly Correlated Electrons · Physics 2023-04-07 Jia-Bao Wang , Yi Zhang

We investigate a measure of quantum coherence and its extension to quantify quantum macroscopicity. The coherence measure can also quantify the asymmetry of a quantum state with respect to a given group transformation. We then show that a…

Quantum Physics · Physics 2018-02-14 Hyukjoon Kwon , Chae-Yeun Park , Kok Chuan Tan , Daekun Ahn , Hyunseok Jeong

We introduce new measures of decoherence appropriate for evaluation of quantum computing designs. Environment-induced deviation of a quantum system's evolution from controlled dynamics is quantified by a single numerical measure. This…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Leonid Fedichkin , Arkady Fedorov , Vladimir Privman

It is not possible to obtain information about the observable properties of a quantum system without a physical interaction between the system and an external meter. This physical interaction is described by a unitary transformation of the…

Quantum Physics · Physics 2021-07-29 Tomonori Matsushita , Holger F. Hofmann

Fidelity is the standard measure for quantifying the similarity between two quantum states. It is equal to the square of the minimum Bhattacharyya coefficient between the probability distributions induced by quantum measurements on the two…

Quantum Physics · Physics 2025-12-01 Datong Chen , Huangjun Zhu

The laws of quantum mechanics place fundamental limits on the accuracy of measurements and therefore on the estimation of unknown parameters of a quantum system. In this work, we prove lower bounds on the size of confidence regions reported…

Quantum Physics · Physics 2014-12-23 Michael Walter , Joseph M. Renes

We show that probabilities of results of all possible measurements performing on a quantum system depend on the system's state only through its density matrix. Therefore all experimentally available information about the state contains in…

Quantum Physics · Physics 2016-02-01 Alexey Nenashev

What is the observer's role in quantum measurement? Obviously, observers prepare the apparatus, observe and interpret the measured results. Although the observer will have a certain influence on the measurement results by setting up the…

Quantum Physics · Physics 2022-11-01 Lizhi Xin , Houwen Xin

Pivotal within quantum physics, the concept of quantum incompatibility is generally related to algebraic aspects of the formalism, such as commutation relations and unbiasedness of bases. Recently, the concept was identified as a resource…

Quantum Physics · Physics 2020-12-24 E. Martins , M. F. Savi , R. M. Angelo

Knowledge of optimal quantum measurements is important for a wide range of situations, including quantum communication and quantum metrology. Quantum measurements are usually optimised with an ideal experimental realisation in mind. Real…

Quantum Physics · Physics 2015-06-03 Erika Andersson

Quantum uncertainty is described here in two guises: indeterminacy with its concomitant indeterminism of measurement outcomes, and fuzziness, or unsharpness. Both features were long seen as obstructions of experimental possibilities that…

Quantum Physics · Physics 2011-01-04 Paul Busch

Quantum theory (QT) provides statistical predictions for various physical phenomena. The outcomes of these measurements are in general some numerical time series registered by some macroscopic instruments. The various empirical probability…

Quantum Physics · Physics 2015-05-13 Marian Kupczynski

We provide a compendium of inequalities between several quantum state distinguishability measures. For each measure these inequalities consist of the sharpest possible upper and lower bounds in terms of another measure. Some of these…

Quantum Physics · Physics 2014-10-24 Koenraad M. R. Audenaert