English
Related papers

Related papers: Comparison of Quantum Channels by Superchannels

200 papers

In this work, we study two different approaches to defining the entropy of a quantum channel. One of these is based on the von Neumann entropy of the corresponding Choi-Jamio{\l}kowski state. The second one is based on the relative entropy…

Quantum Physics · Physics 2021-08-17 Dariusz Kurzyk , Łukasz Pawela , Zbigniew Puchała

In this paper a notion of entropy transmission of quantum channels is introduced as a natural extension of Ohya's entropy. Here by quantum channel is meant unital completely positive mappings (ucp) of $B(H)$ into itself, where $H$ is an…

Quantum Physics · Physics 2007-11-21 Nasir Ganikhodjaev , Farrukh Mukhamedov

A bipartite quantum channel represents the interaction between systems, generally allowing for exchange of information. A special class of bipartite channels are the no-signaling ones, which do not allow communication. In Ref. [1] it has…

Quantum Physics · Physics 2011-01-28 Giacomo Mauro D'Ariano , Stefano Facchini , Paolo Perinotti

For a pair of quantum channels with the same input space, we show that the possibility of approximation of one channel by post-processings of the other channel can be characterized by comparing the success probabilities for the two…

Quantum Physics · Physics 2016-04-26 Anna Jencova

For a pair of quantum channels with the same input space, we show that the possibility of approximation of one channel by post-processings of the other channel can be characterized by comparing the success probabilities for the two…

Quantum Physics · Physics 2016-04-26 Anna Jencova

The von Neumann entropy of a quantum state is a central concept in physics and information theory, having a number of compelling physical interpretations. There is a certain perspective that the most fundamental notion in quantum mechanics…

Quantum Physics · Physics 2021-05-12 Gilad Gour , Mark M. Wilde

Quantum addition channels have been recently introduced in the context of deriving entropic power inequalities for finite dimensional quantum systems. We prove a reverse entropy power equality which can be used to analytically prove an…

Quantum Physics · Physics 2026-04-13 Chiranjib Mukhopadhyay , Arun Kumar Pati , Sk Sazim

We introduce new entanglement monotones which generalize, to the case of many parties, those which give rise to the majorization-based partial ordering of bipartite states' entanglement. We give some examples of restrictions they impose on…

Quantum Physics · Physics 2009-11-07 H. Barnum , N. Linden

We study quantum channels with respect to their image, i.e., the image of the set of density operators under the action of the channel. We first characterize the set of quantum channels having polytopic images and show that additivity of…

Quantum Physics · Physics 2015-10-15 Motohisa Fukuda , Ion Nechita , Michael M. Wolf

State transformations in quantum mechanics are described by completely positive maps which are constructed from quantum channels. We call a finest sharp quantum channel a context. The result of a measurement depends on the context under…

Quantum Physics · Physics 2022-09-01 Stan Gudder

This paper provides a characterization for the set of antidegradable qubit channels. The characterization arises from the correspondence between the antidegradability of a channel and the symmetric extendibility of its Choi operator. Using…

Quantum Physics · Physics 2017-12-12 Connor Paddock , Jianxin Chen

This work is an enquiry into the circumstances under which entropy methods can give an answer to the questions of both quantum separability and classical correlations of a composite state. Several entropy functionals are employed to examine…

Quantum Physics · Physics 2009-11-07 A. K. Rajagopal , R. W. Rendell

Quantum coherence characterizes the non-classical feature of a single party system with respect to a local basis. Based on a recently introduced resource framework, coherence can be regarded as a resource and be systematically manipulated…

Quantum Physics · Physics 2018-09-26 Yunchao Liu , Qi Zhao , Xiao Yuan

The minimum entropy output is computed for rotationally invariant quantum channels acting on spin-1/2 and spin-1 systems. For the case of two parallel such channels and initial entangled (singlet) state the entropy of the output is higher…

Quantum Physics · Physics 2007-05-23 Robert Alicki

In this thesis, I studied a mathematical development to define and quantify the uncertainty inherent in classical channels. This thesis starts with the introduction and background on how to formally think about uncertainty in the domain of…

Quantum Physics · Physics 2025-07-17 Takla Nateeboon

The quantum channel-state duality permits the characterization of a quantum process through a quantum state, referred to as a Choi state. This characteristic serves as the impetus for the quantum computing paradigm that utilizes Choi states…

Quantum Physics · Physics 2025-04-03 Y. -D. Liu , D. -S. Wang

Quantum memories are a crucial precondition in many protocols for processing quantum information. A fundamental problem that illustrates this statement is given by the task of channel discrimination, in which an unknown channel drawn from a…

Quantum Physics · Physics 2026-01-28 Ties-A. Ohst , Shijun Zhang , Hai Chau Nguyen , Martin Plávala , Marco Túlio Quintino

It is well-known that the action of a quantum channel on a state can be represented, using an auxiliary space, as the partial trace of an associated bipartite state. Recently, it was observed that for the bipartite state associated with the…

Quantum Physics · Physics 2007-05-23 Mary Beth Ruskai

We prove that, when two local quantum channels are used paralleled, the quantum-correlating power (QCP) of the composed channel is no less than the sum of QCP of the two channels. For local channels with zero QCP, the super-activation of…

Quantum Physics · Physics 2013-07-23 Xueyuan Hu , Heng Fan , D. L. Zhou , Wu-Ming Liu

The von Neumann entropy plays a vital role in quantum information theory. The von Neumann entropy determines, e.g., the capacities of quantum channels. Also, entropies of composite quantum systems are important for future quantum networks,…

Quantum Physics · Physics 2018-10-31 Christian Majenz