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We introduce potential capacities of quantum channels in an operational way and provide upper bounds for these quantities, which quantify the ultimate limit of usefulness of a channel for a given task in the best possible context.…

Quantum Physics · Physics 2016-02-17 Andreas Winter , Dong Yang

One of the major achievements of the recently emerged quantum information theory is the introduction and thorough investigation of the notion of quantum channel which is a basic building block of any data-transmitting or data-processing…

Quantum Physics · Physics 2012-03-23 A. S. Holevo , V. Giovannetti

Quantum mechanics sets severe limits on the sensitivity and required circulating energy in traditional free-mass gravitational-wave antennas. One possible way to avoid these restrictions is the use of intracavity QND measurements. We…

Quantum Physics · Physics 2009-10-31 Vladimir B. Braginsky , Michael L. Gorodetsky , Farid Ya. Khalili

The present paper is devoted to investigation of the entropy reduction and entanglement-assisted classical capacity (information gain) of continuous variable quantum measurements. These quantities are computed explicitly for multimode…

Quantum Physics · Physics 2020-08-31 A. S. Holevo , A. A. Kuznetsova

In this work, we investigate the dynamics of quantum correlations captured by entropic and geometric measures of discord under the influence of dissipative channels for widely used two qubit X state with maximally mixed marginals.…

Quantum Physics · Physics 2022-05-31 Nitish Kumar Chandra , Sarang S. Bhosale , Prasanta K. Panigrahi

Entanglement entropy, which is a measure of quantum correlations between separate parts of a many-body system, has emerged recently as a fundamental quantity in broad areas of theoretical physics, from cosmology and field theory to…

Quantum Physics · Physics 2009-03-09 Israel Klich , Leonid Levitov

A fundamental question in information theory is to quantify the loss of information under a noisy channel. Partial orders and contraction coefficients are typical tools to that end, however, they are often also challenging to evaluate. For…

Information Theory · Computer Science 2026-05-21 Christoph Hirche , Oxana Shaya

We derive quantum constraints on the minimal amount of noise added in linear amplification involving input or output signals whose component operators do not necessarily have c-number commutators, as is the case for fermion currents. This…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 U. Gavish , B. Yurke , Y. Imry

We give new upper and lower bounds on the concavity of quantum entropy. Comparisons are given with other results in the literature.

Quantum Physics · Physics 2015-06-19 Isaac H. Kim , Mary Beth Ruskai

The problem of measurement in quantum mechanics is studied within the Entropic Dynamics framework. We discuss von Neumann and Weak measurements, wavefunction collapse, and Weak Values as examples of bayesian and entropic inference.

Quantum Physics · Physics 2017-06-28 Kevin Vanslette , Ariel Caticha

We introduce the theory of operator monotone functions and employ it to derive a new inequality relating the quantum relative entropy and the quantum conditional entropy. We present applications of this new inequality and in particular we…

Quantum Physics · Physics 2009-11-06 M. B. Plenio , S. Virmani , P. Papadopoulos

Monotonicity under coarse-graining is a crucial property of the quantum relative entropy. The aim of this paper is to investigate the condition of equality in the monotonicity theorem and in its consequences such as the strong…

Quantum Physics · Physics 2009-11-07 D. Petz

Quantum communication relies on the existence of high quality quantum channels to exchange information. In practice, however, all communication links are affected by noise from the environment. Here we investigate the ability of quantum…

Quantum Physics · Physics 2025-08-12 Vishal Singh , Mark M. Wilde

The unitary dynamics of quantum systems can be modeled as a trajectory on a Riemannian manifold. This theoretical framework naturally yields a purely geometric interpretation of computational complexity for quantum algorithms, a notion…

Quantum Physics · Physics 2025-07-25 Alberto Acevedo , Antonio Falco

Two quantum channels are called compatible if they can be obtained as marginals from a single broadcasting channel; otherwise they are incompatible. We derive a characterization of the compatibility relation in terms of concatenation and…

Quantum Physics · Physics 2017-03-06 Teiko Heinosaari , Takayuki Miyadera

In this paper, we introduce the framework for quantifying the imaginarity of quantum channels. Besides, an alternative framework is given together to simplify the process of verifying the condition. We present three imaginarity measures of…

Quantum Physics · Physics 2025-02-25 Xiangyu Chen , Qiang Lei

We analyze the quality of the quantum information transmission along a correlated quantum channel by studying the average fidelity between input and output states and the average output purity, giving bounds for the entropy of the channel.…

Quantum Physics · Physics 2008-11-26 Davide Rossini , Vittorio Giovannetti , Simone Montangero

Werner states have a host of interesting properties, which often serve to illuminate the unusual properties of quantum information. Starting from these states, one may define a family of quantum channels, known as the Holevo-Werner…

Quantum Physics · Physics 2018-11-15 Thomas P. W. Cope , Kenneth Goodenough , Stefano Pirandola

Quantum Renyi relative entropies provide a one-parameter family of distances between density matrices, which generalizes the relative entropy and the fidelity. We study these measures for renormalization group flows in quantum field theory.…

High Energy Physics - Theory · Physics 2018-10-17 Horacio Casini , Raimel Medina , Ignacio Salazar , Gonzalo Torroba

We review recent results on the simulation of quantum channels, the reduction of adaptive protocols (teleportation stretching), and the derivation of converse bounds for quantum and private communication, as established in PLOB [Pirandola,…