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Related papers: Some properties of partial fidelities

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A family of quantum measures like the Shannon distinguishability is presented. These measures are defined over the two classes of POVM measurements and related to separate parts in the expression for mutual information. Changes of Ky Fan's…

Quantum Physics · Physics 2011-03-02 Alexey E. Rastegin

New quantum distance is introduced as a half-sum of several singular values of difference between two density operators. This is, up to factor, the metric induced by so-called Ky Fan norm. The partitioned trace distances enjoy similar…

Quantum Physics · Physics 2010-03-29 Alexey E. Rastegin

The notion of partial fidelities as invented recently by A.Uhlmann for pairs of finite dimensional density matrices will be extended to the vN-algebraic context and is considered and thoroughly discussed in detail from a mathematical point…

Mathematical Physics · Physics 2015-11-18 Peter M. Alberti

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

The main contribution of our paper is to introduce a number of multivariate quantum fidelities and show that they satisfy several desirable properties that are natural extensions of those of the Uhlmann and Holevo fidelities. We propose…

Quantum Physics · Physics 2025-06-17 Theshani Nuradha , Hemant K. Mishra , Felix Leditzky , Mark M. Wilde

We study tree kinds of quantum fidelity. Usual Uhlmann's fidelity, minus of f-divergence when $f(x)=-\sqrt{x}$, and the one introduced by the author via reverse test. All of them are quantum extensions of classical fidelity, where the first…

Quantum Physics · Physics 2014-08-18 Keiji Matsumoto

Applications of quantum technology often require fidelities to quantify performance. These provide a fundamental yardstick for the comparison of two quantum states. While this is straightforward in the case of pure states, it is much more…

Uhlmann's fidelity function is one of the most widely used similarity measures in quantum theory. One definition of this function is that it is the minimum classical fidelity associated with a quantum-to-classical measurement procedure of…

Quantum Physics · Physics 2021-01-19 Sam Cree , Jamie Sikora

Extensions of Fannes' inequality with partial sums of the Tsallis entropy are obtained for both the classical and quantum cases. The definition of kth partial sum under the prescribed order of terms is given. Basic properties of introduced…

Quantum Physics · Physics 2011-06-03 Alexey E. Rastegin

Various fidelity measures can be defined between two quantum processes especially when at least one of them is non-unitary. In this paper we consider two such measures of state averaged process fidelity, put forward an efficient procedure…

Mathematical Physics · Physics 2011-11-11 Joydip Ghosh

For pairs, omega, rho, of density operators on a finite dimensional Hilbert space of dimension d I call k-fidelity the d - k smallest eigenvalues of | omega^1/2 rho^1/2 |. k-fidelities are jointly concave in omega, rho. This follows by…

Quantum Physics · Physics 2009-10-31 Armin Uhlmann

The entanglement fidelity provides a measure of how well the entanglement between two subsystems is preserved in a quantum process. By using a simple model we show that in some cases this quantity in its original definition fails in the…

Quantum Physics · Physics 2009-11-13 Yang Xiang , Shi-Jie Xiong

We consider several definitions of the quantum Wasserstein distance based on an optimization over general bipartite quantum states with given marginals. Then, we examine the quantities obtained after the optimization is carried out over…

Quantum Physics · Physics 2026-05-15 Géza Tóth , József Pitrik

The fidelity susceptibility measures sensitivity of eigenstates to a change of an external parameter. It has been fruitfully used to pin down quantum phase transitions when applied to ground states (with extensions to thermal states). Here…

Disordered Systems and Neural Networks · Physics 2020-04-10 Piotr Sierant , Artur Maksymov , Marek Kuś , Jakub Zakrzewski

The fidelity (Shannon mutual information between measurements and physical quantities) is proposed as a quantitative measure of the quality of physical measurements. The fidelity does not depend on the true value of unknown physical…

Quantum Physics · Physics 2011-03-15 Thomas B. Bahder

We introduce a definition of the fidelity function for multi-round quantum strategies, which we call the strategy fidelity, that is a generalization of the fidelity function for quantum states. We provide many properties of the strategy…

Quantum Physics · Physics 2019-02-12 Gus Gutoski , Ansis Rosmanis , Jamie Sikora

We analyze the Uhlmann fidelity of a pair of $n$-mode Gaussian states of the quantum radiation field. This quantity is shown to be the product of an exponential function depending on the relative average displacement and a factor fully…

Quantum Physics · Physics 2015-06-03 Paulina Marian , Tudor A. Marian

The fundamental principles of complementarity and uncertainty are shown to be related to the possibility of joint unsharp measurements of pairs of noncommuting quantum observables. A new joint measurement scheme for complementary…

Quantum Physics · Physics 2009-11-07 P. Busch , C. R. Shilladay

The partial correlation coefficient is a commonly used measure to assess the conditional dependence between two random variables. We provide a thorough explanation of the partial copula, which is a natural generalization of the partial…

Methodology · Statistics 2017-06-13 Fabian Spanhel , Malte S. Kurz

Quantum fidelity is a measure to quantify the closeness of two quantum states. In an operational sense, it is defined as the minimal overlap between the probability distributions of measurement outcomes and the minimum is taken over all…

Quantum Physics · Physics 2019-07-24 Changhun Oh , Changhyoup Lee , Leonardo Banchi , Su-Yong Lee , Carsten Rockstuhl , Hyunseok Jeong
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