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Related papers: CPDNN quantum channels with qubit output are CPCP

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The complete positivity vs positivity correspondence in the Choi-Jamio{\l}kowski-Kraus-Sudarshan quantum channel-state isomorphism depends on the choice of basis. Instead of the "canonical" basis, if we use, e.g., the Pauli spin matrices…

Quantum Physics · Physics 2023-08-24 Sohail , Sahil , Ritabrata Sengupta , Ujjwal Sen

Certification of quantum channels is based on quantum hypothesis testing and involves also preparation of an input state and choosing the final measurement. This work primarily focuses on the scenario when the false negative error cannot…

Quantum Physics · Physics 2023-01-11 Aleksandra Krawiec , Łukasz Pawela , Zbigniew Puchała

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

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

Quantum masking is a special type of secret sharing in which some information gets reversibly distributed into a multipartite system, leaving the original information inaccessible to each subsystem. This paper proposes a dynamical extension…

Quantum Physics · Physics 2026-05-07 Anna Honeycutt , Hailey Murray , Eric Chitambar

Quantum convolutional neural networks (QCNNs) have gathered attention as one of the most promising algorithms for quantum machine learning. Reduction in the cost of training as well as improvement in performance is required for practical…

We propose a categorical foundation for the connection between pure and mixed states in quantum information and quantum computation. The foundation is based on distributive monoidal categories. First, we prove that the category of all…

Logic in Computer Science · Computer Science 2019-04-25 Mathieu Huot , Sam Staton

Quantum channels describe subsystem or open system evolution. Using the classical Koopman operator that evolves functions on phase space, 4 classical Koopman channels are identified that are analogs of the 4 possible quantum channels in a…

Quantum Physics · Physics 2024-07-22 Bidhi Vijaywargia , Arul Lakshminarayan

The strong capacity of a particular channel can be interpreted as a sharp limit on the amount of information which can be transmitted reliably over that channel. To evaluate the strong capacity of a particular channel one must prove both…

Quantum Physics · Physics 2011-10-20 Tony Dorlas , Ciara Morgan

We provide new results for computing and comparing the quantum gate fidelity of quantum channels via their Choi matrices. We extend recent work that showed there exist non-dual pairs of quantum channels with equal gate fidelity by providing…

Quantum Physics · Physics 2012-03-06 Nathaniel Johnston , David W. Kribs

In the problem of quantum channel certification, we have black box access to a quantum process and would like to decide if this process matches some predefined specification or is $\varepsilon$-far from this specification. The objective is…

Quantum Physics · Physics 2024-11-15 Omar Fawzi , Nicolas Flammarion , Aurélien Garivier , Aadil Oufkir

We determine both the quantum and the private capacities of low-noise quantum channels to leading orders in the channel's distance to the perfect channel. It has been an open problem for more than 20 years to determine the capacities of…

Quantum Physics · Physics 2023-12-06 Felix Leditzky , Debbie Leung , Graeme Smith

The maximum rates for information transmission through noisy quantum channels has primarily been developed for memoryless channels, where the noise on each transmitted state is treated as independent. Many real world communication channels…

Quantum Physics · Physics 2009-11-10 Garry Bowen , Igor Devetak , Stefano Mancini

The method of complementary channel for analysis of reversibility (sufficiency) of a quantum channel with respect to families of input states (pure states for the most part) are considered and applied to Bosonic linear (quasi-free)…

Quantum Physics · Physics 2013-11-12 M. E. Shirokov

In this thesis we analyse the type of states and ensembles which achieve the capacity for certain quantum channels carrying classical information. We first concentrate on the product-state capacity of a particular quantum channel, that is,…

Quantum Physics · Physics 2010-07-19 Ciara Morgan

Selfcomplementary quantum channels are characterized by such an interaction between the principal quantum system and the environment that leads to the same output states of both interacting systems. These maps can describe approximate…

Quantum Physics · Physics 2018-03-20 Marek Smaczynski , Wojciech Roga , Karol Zyczkowski

We make a thorough study of the spreading of quantum coherence (QC), as quantified by the $l_{1}$-norm QC, when a qubit (a two-level quantum system) is subjected to noise quantum channels commonly appearing in quantum information science.…

Quantum Physics · Physics 2017-02-10 Mauro B. Pozzobom , Jonas Maziero

A necessary condition for reversibility (sufficiency) of a quantum channel with respect to complete families of states with bounded rank is obtained. A full description (up to isometrical equivalence) of all quantum channels reversible with…

Quantum Physics · Physics 2015-06-04 M. E. Shirokov

According to the statistical interpretation of quantum theory, quantum computers form a distinguished class of probabilistic machines (PMs) by encoding n qubits in 2n pbits (random binary variables). This raises the possibility of a…

Quantum Physics · Physics 2007-05-23 P. Gralewicz

Unital quantum channels, defined by their property of leaving the maximally mixed state invariant, form an important class of quantum operations. A distinguished subset of these channels can be represented as a probabilistic mixture of…

Quantum Physics · Physics 2026-03-19 Charlotte Bäcker , Konstantin Beyer , Walter T. Strunz