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Quantum channels can be activated by a kind of channels whose quantum capacity is zero. This activation effect might be useful to overcome noise of channels by attaching other channels which can enhance the capacity of a given channel. In…

Quantum Physics · Physics 2018-07-26 Youngrong Lim , Soojoon Lee

We show that entanglement is a useful resource to enhance the mutual information of the depolarizing channel when the noise on consecutive uses of the channel has some partial correlations. We obtain a threshold in the degree of memory,…

Quantum Physics · Physics 2009-11-07 Chiara Macchiavello , G. Massimo Palma

Quantum computing promises to revolutionize several scientific and technological domains through fundamentally new ways of processing information. Among its most compelling applications is digital quantum simulation, where quantum computers…

Quantum Physics · Physics 2026-02-05 Laurin E. Fischer

The classical product state capacity of a noisy quantum channel with memory is investigated. A forgetful noise-memory channel is constructed by Markov switching between two depolarizing channels which introduces non-Markovian noise…

Quantum Physics · Physics 2009-06-23 Jeroen Wouters , Ismail Akhalwaya , Mark Fannes , Francesco Petruccione

Capacities of quantum channels and decoherence times both quantify the extent to which quantum information can withstand degradation by interactions with its environment. However, calculating capacities directly is known to be intractable…

Quantum Physics · Physics 2021-06-07 Ivan Bardet , Marius Junge , Nicholas LaRacuente , Cambyse Rouzé , Daniel Stilck França

Entanglement distillation is a fundamental information processing task whose implementation is key to quantum communication and modular quantum computing. Noise experienced by such communication and computing platforms occurs not only in…

Quantum Physics · Physics 2025-07-29 Vikesh Siddhu , Dina Abdelhadi , Tomas Jochym-O'Connor , John Smolin

Hypercontractive inequalities have become important tools in theoretical computer science and have recently found applications in quantum computation. In this note we discuss how hypercontractive inequalities, in various settings, can be…

Quantum Physics · Physics 2015-06-11 Ashley Montanaro

We study many-qubit generalizations of quantum noise channels that can be written as an incoherent sum of translations in phase space. Physical description in terms of the spectral properties of the superoperator and the action in phase…

Quantum Physics · Physics 2009-11-10 Mario Leandro Aolita , Ignacio Garcia-Mata , Marcos Saraceno

Quantum sensors leverage nonclassical resources to achieve sensing precision at the Heisenberg limit, surpassing the standard quantum limit attainable through classical strategies. However, a critical issue is that the environmental noise…

Quantum Physics · Physics 2025-11-24 Hang Xu , Tailong Xiao , Jingzheng Huang , Jianping Fan , Guihua Zeng

Incompatibility of quantum devices is one of the cornerstones of quantum theory, and the incompatibility of quantum measurements and channels has been linked to quantum advantage in certain information theoretic tasks. In this work, we…

Quantum Physics · Physics 2023-03-28 Arindam Mitra , Máté Farkas

The paper analyzes the behavior of quantum channels, particularly in large dimensions, by proving various properties of the quantum gate fidelity. Many of these properties are of independent interest in the theory of distance measures on…

Quantum Physics · Physics 2011-07-12 Easwar Magesan

Thermal attenuator channels model the decoherence of quantum systems interacting with a thermal bath, e.g., a two-level system subject to thermal noise and an electromagnetic signal travelling through a fiber or in free-space. Hence…

Quantum Physics · Physics 2018-12-12 Matteo Rosati , Andrea Mari , Vittorio Giovannetti

A major challenge in quantum communication is addressing the negative effects of noise on channel capacity, especially for completely depolarizing channels, where information transmission is inherently impossible. The concept of indefinite…

This paper studies the computational and statistical aspects of quantile and pseudo-Huber tensor decomposition. The integrated investigation of computational and statistical issues of robust tensor decomposition poses challenges due to the…

Statistics Theory · Mathematics 2023-09-07 Yinan Shen , Dong Xia

We experimentally demonstrate the achievement of the entanglement assisted capacity for classical information transmission over a depolarizing channel. The implementation is based on the generation and local manipulation of 2-qubit Bell…

Quantum Physics · Physics 2015-06-05 Andrea Chiuri , Sandro Giacomini , Chiara Macchiavello , Paolo Mataloni

We investigate effective noise channels for encoded quantum systems with and without active error correction. Noise acting on physical qubits forming a logical qubit is thereby described as a logical noise channel acting on the logical…

Quantum Physics · Physics 2013-10-30 Frederik Kesting , Florian Fröwis , Wolfgang Dür

Quantum information processing offers dramatic speedups, yet is famously susceptible to decoherence, the process whereby quantum superpositions decay into mutually exclusive classical alternatives, thus robbing quantum computers of their…

Quantum Physics · Physics 2014-08-21 Kristen L. Pudenz , Tameem Albash , Daniel A. Lidar

We present a simple model of quantum communication where a noisy quantum channel may benefit from the addition of further noise at the decoding stage. We demonstrate enhancement of the classical information capacity of an amplitude damping…

Quantum Physics · Physics 2015-06-26 Garry Bowen , Stefano Mancini

The quantum capacity of a noisy quantum channel determines the maximal rate at which we can code reliably over asymptotically many uses of the channel, and it characterizes the channel's ultimate ability to transmit quantum information…

Quantum Physics · Physics 2021-10-26 Xin Wang

We investigate the quantum capacity of noisy quantum channels which can be represented by coupling a system to an effectively small environment. A capacity formula is derived for all cases where both system and environment are…

Quantum Physics · Physics 2009-11-13 Michael M. Wolf , David Perez-Garcia