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Related papers: A short note on the 0-fidelity

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A quantum processor is a programmable quantum circuit in which both the data and the program, which specifies the operation that is carried out on the data, are quantum states. We study the situation in which we want to use such a processor…

Quantum Physics · Physics 2009-11-11 Mark Hillery , Mario Ziman , Vladimir Buzek

Fidelity is a fundamental and ubiquitous concept in quantum information theory. Fuchs-van de Graaf's inequalities deal with bounding fidelity from above and below. In this paper, we give a lower bound on the quantum fidelity between two…

Quantum Physics · Physics 2016-04-06 Lin Zhang , Kaifeng Bu , Junde Wu

Fidelity is crucial for characterizing transformations of quantum states under various quantum channels, which can be served as a fundamental tool in resource theories. Firstly, we define an $\alpha$-$z$-fidelity as a significant quantity…

Quantum Physics · Physics 2025-07-08 Xiaojing Yan , Xiao Sun , Mingming Du , Jiashan Tang

Computing quantum state fidelity will be important to verify and characterize states prepared on a quantum computer. In this work, we propose novel lower and upper bounds for the fidelity $F(\rho,\sigma)$ based on the "truncated fidelity"…

Quantum Physics · Physics 2020-03-27 M. Cerezo , Alexander Poremba , Lukasz Cincio , Patrick J. Coles

We compare and contrast the error probability and fidelity as measures of the quality of the receiver's measurement strategy for a quantum communications system. The error probability is a measure of the ability to retrieve {\it classical}…

Quantum Physics · Physics 2009-11-07 Stephen M. Barnett , Claire R. Gilson , Masahide Sasaki

We study the optimization of any quantum process by minimizing the "randomness" in the measurement result at the output of that quantum process. We conceptualize and propose a measure of such randomness and inquire whether an optimization…

Quantum Physics · Physics 2021-03-30 Sreetama Das , Asutosh Kumar , Aditi Sen De , Ujjwal Sen

Quantum fidelity is one of the most important measures of similarity between mixed quantum states. However, the usual formulation is cumbersome and hard to understand when encountering the first time. This work shows in a novel, elegant…

Quantum Physics · Physics 2023-10-11 Adrian Müller

We provide a bound for the trace distance between two quantum states. The lower bound is based on the superfidelity, which provides the upper bound on quantum fidelity. One of the advantages of the presented bound is that it can be…

Quantum Physics · Physics 2009-02-11 Zbigniew Puchała , Jarosław Adam Miszczak

Opacity is an important information-flow security property in the analysis of cyber-physical systems. It captures the plausible deniability of the system's secret behavior in the presence of an intruder that may access the information flow.…

Systems and Control · Computer Science 2019-02-26 Xiang Yin , Majid Zamani

We are interested in the problem of characterizing the correlations that arise when performing local measurements on separate quantum systems. In a previous work [Phys. Rev. Lett. 98, 010401 (2007)], we introduced an infinite hierarchy of…

Quantum Physics · Physics 2009-01-16 Miguel Navascues , Stefano Pironio , Antonio Acin

We apply the fidelity metric approach to analyze two recently introduced models that exhibit a quantum phase transition to a topologically ordered phase. These quantum models have a known connection to classical statistical mechanical…

Quantum Physics · Physics 2008-07-03 Damian F. Abasto , Alioscia Hamma , Paolo Zanardi

This paper studies privacy and secure function evaluation in communication complexity. The focus is on quantum versions of the model and on protocols with only approximate privacy against honest players. We show that the privacy loss (the…

Quantum Physics · Physics 2007-05-23 Hartmut Klauck

We define and study a fidelity criterion for quantum channels, which we term the minimax fidelity, through a noncommutative generalization of maximal Hellinger distance between two positive kernels in classical probability theory. Like…

Quantum Physics · Physics 2009-11-10 Viacheslav P. Belavkin , Giacomo Mauro D'Ariano , Maxim Raginsky

Estimating the fidelity with a target state is important in quantum information tasks. Many fidelity estimation techniques present a suitable measurement scheme to perform the estimation. In contrast, we present techniques that allow the…

Quantum Physics · Physics 2024-07-12 Akshay Seshadri , Martin Ringbauer , Jacob Spainhour , Thomas Monz , Stephen Becker

We study quantum fidelity, the overlap between two ground states of a many-body system, focusing on the thermodynamic regime. We show how drop of fidelity near a critical point encodes universal information about a quantum phase transition.…

Quantum Physics · Physics 2015-05-20 Marek M. Rams , Bogdan Damski

A fundamental task in any physical theory is to quantify certain physical quantity in a meaningful way. In this paper we show that both fidelity distance and affinity distance satisfy the strong contractibility, and the corresponding…

Quantum Physics · Physics 2019-03-05 Chunhe Xiong , Asutosh Kumar , Minyi Huang , Sreetama Das , Ujjwal Sen , Junde Wu

Fidelity is arguably the most popular figure of merit in quantum sciences. However, many of its properties are still unknown. In this work, we resolve the open problem of maximizing average fidelity over arbitrary finite ensembles of…

Quantum Physics · Physics 2022-06-17 A. Afham , Richard Kueng , Chris Ferrie

We give asymptotically converging semidefinite programming hierarchies of outer bounds on bilinear programs of the form $\mathrm{Tr}\big[M(X\otimes Y)\big]$, maximized with respect to semidefinite constraints on $X$ and $Y$. Applied to the…

Quantum Physics · Physics 2021-07-13 Mario Berta , Francesco Borderi , Omar Fawzi , Volkher Scholz

Gate fidelity -- an average fidelity over all possible input states -- is the workhorse metric for benchmarking quantum gates or circuits, yet fault-tolerant quantum computing ultimately depends on the worst-case behavior, typically…

Quantum Physics · Physics 2026-03-10 Kyoungho Cho , Ilkwon Sohn , Yongsoo Hwang , Jeongho Bang

Coherence and correlation are key features of the quantum system. Quantifying these quantities are astounding task in the framework of resource theory of quantum information processing. In this article, we identify an affinity-based metric…

Quantum Physics · Physics 2021-02-11 R. Muthuganesan , V. K. Chandrasekar , R. Sankaranarayanan