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Related papers: Some properties of partial fidelities

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Uhlmann's theorem is a cornerstone of quantum information theory, stating that for any quantum state $\rho_{AB}$ and any state $\sigma_A$, there exists an extension $\sigma_{AB}$ of $\sigma_A$ such that the fidelity between $\rho_{AB}$ and…

Quantum Physics · Physics 2026-03-03 Kun Fang , Hamza Fawzi , Omar Fawzi

We propose partial measurements as a conceptual tool to understand how to operate with counterfactual claims in quantum physics. Indeed, unlike standard von Neumann measurements, partial measurements can be reversed probabilistically. We…

Quantum Physics · Physics 2011-05-30 G. S. Paraoanu

Fidelity and relative entropy are two significant quantities in quantum information theory. We study the quantum fidelity and relative entropy under unitary orbits. The maximal and minimal quantum fidelity and relative entropy between two…

Quantum Physics · Physics 2014-01-15 Lin Zhang , Shao-Ming Fei

Purity and coherence of a quantum state are recognized as useful resources for various information processing tasks. In this article, we propose a fidelity based valid measure of purity and coherence monotone and establish a relationship…

Quantum Physics · Physics 2021-04-09 Indrajith V S , R. Muthuganesan , R. Sankaranarayanan

In this paper we discuss the fidelity of states in infinite dimensional systems, give an elementary proof of the infinite dimensional version of Uhlmann's theorem, and then, apply it to generalize several properties of the fidelity from…

Quantum Physics · Physics 2011-07-05 Jinchuan Hou , Xiaofei Qi

The paper analyzes the behavior of quantum channels, particularly in large dimensions, by proving various properties of the quantum gate fidelity. Many of these properties are of independent interest in the theory of distance measures on…

Quantum Physics · Physics 2011-07-12 Easwar Magesan

We examine the physical significance of fidelity as a measure of similarity for Gaussian states, by drawing a comparison with its classical counterpart. We find that the relationship between these classical and quantum fidelities is not…

Quantum Physics · Physics 2015-06-26 H. Jeong , T. C. Ralph , W. P. Bowen

We investigate the coherence measures induced by fidelity and trace norm, based on the recent proposed coherence quantification in [Phys. Rev. Lett. 113, 140401, 2014]. We show that the fidelity of coherence does not in general satisfy the…

Quantum Physics · Physics 2015-04-22 Lian-He Shao , Zhengjun Xi , Heng Fan , Yongming Li

The notion of partial trace of a density operator is essential for the understanding of the entanglement and separability properties of quantum states. In this paper we investigate these notions putting an emphasis on the geometrical…

Quantum Physics · Physics 2023-03-21 Nuno Costa Dias , Maurice de Gosson , Joao Nuno Prata

We revisit the fidelity as a measure for the stability and the complexity of the quantum motion of single and many-body systems. Within the context of cold atoms, we present on overview of applications of two fidelities which we call static…

Quantum Gases · Physics 2016-05-23 Sandro Wimberger

Fidelity serves as a benchmark for the relieability in quantum information processes, and has recently atracted much interest as a measure of the susceptibility of dynamics to perturbations. A rich variety of regimes for fidelity decay have…

Quantum Physics · Physics 2007-05-23 Thomas Gorin , Tomaz Prosen , Thomas H. Seligman , Marko Znidaric

Present-day quantum devices require precise implementation of desired quantum channels. To characterize the quality of implementation one uses the average operation fidelity $F$, defined as the fidelity between an initial pure state and its…

Quantum Physics · Physics 2024-03-18 Igor Chełstowski , Grzegorz Rajchel-Mieldzioć , Karol Życzkowski

A distance measure is presented between two unitary propagators of quantum systems of differing dimensions along with a corresponding method of computation. A typical application is to compare the propagator of the actual (real) process…

Quantum Physics · Physics 2007-05-23 Robert L. Kosut , Matthew Grace , Constantin Brif , Herschel Rabitz

Quantum coherence is a fundamental feature of quantum physics and plays a significant role in quantum information processing. By generalizing the resource theory of coherence from von Neumann measurements to positive operator-valued…

Quantum Physics · Physics 2023-05-12 Meng-Li Guo , Jin-Min Liang , Bo Li , Shao-Ming Fei , Zhi-Xi Wang

The discrimination of quantum states is a central problem in quantum information science and technology. Meanwhile, partial post-selection has emerged as a valuable tool for quantum state engineering. In this work, we bring these two areas…

Quantum Physics · Physics 2026-04-14 Qipeng Qian , Christos N. Gagatsos

Two measures of fidelity are proposed for postselecting devices, the retrodictive conditional probability that the state in the measurement arm is the one indicated by the detectors, and the probability that the device produces the state…

Quantum Physics · Physics 2009-11-13 John Jeffers

Fidelity is a figure of merit widely employed in quantum technology in order to quantify similarity between quantum states and, in turn, to assess quantum resources or reconstruction techniques. Fidelities higher than, say, 0.9 or 0.99, are…

Quantum Physics · Physics 2015-06-17 Matteo Bina , Antonio Mandarino , Stefano Olivares , Matteo G. A. Paris

We present examples of continuous variable (CV) states having high fidelity to a given target, say $F > 0.9$ or $F > 0.99$, and still showing striking differences in their physical properties, including classical and quantum states within…

Quantum Physics · Physics 2014-07-03 Antonio Mandarino , Matteo Bina , Stefano Olivares , Matteo G. A. Paris

Distance covariance and distance correlation are scalar coefficients that characterize independence of random vectors in arbitrary dimension. Properties, extensions, and applications of distance correlation have been discussed in the recent…

Methodology · Statistics 2014-07-10 Gabor J. Szekely , Maria L. Rizzo

Based upon the newly proposed partial quantum statistics [T. Zhou, Solid State Commun. 115, 185 (2000)], some canonical physical properties of partially localized electron systems have been calculated. The calculated transport and…

Strongly Correlated Electrons · Physics 2016-08-31 T. Zhou