English
Related papers

Related papers: Classical capacity of a qubit depolarizing channel…

200 papers

This paper investigates the zero-error capacity of channels with memory. Motivated by the nuanced requirements of semantic communication that incorporate memory, we advance the classical enlightened dictator channel by introducing a new…

Information Theory · Computer Science 2024-11-21 Qi Cao , Yulin Shao , Shangwei Ge

We consider the problem of transmitting classical information over a time-invariant channel with memory. A popular class of time-invariant channels with memory are finite-state-machine channels, where a \emph{classical} state evolves over…

Information Theory · Computer Science 2022-07-22 Michael X. Cao , Pascal O. Vontobel

We study the effect of correlated Markovian noise channels on the quantum speed limit of an open system. This is done for correlated dephasing and amplitude damping channels for a two qubit atomic model. Our model serves as a platform for a…

Quantum Physics · Physics 2021-02-18 Natasha Awasthi , U. C. Johri

In the first part of this work we show how certain techniques from quantum information theory can be used in order to obtain very sharp embeddings between noncommutative $L_p$-spaces. Then, we use these estimates to study the classical…

Operator Algebras · Mathematics 2014-07-30 Marius Junge , Carlos Palazuelos

Calculating the capacity of interference channels is a notorious open problem in classical information theory. Such channels have two senders and two receivers, and each sender would like to communicate with a partner receiver. The capacity…

Quantum Physics · Physics 2012-05-28 Omar Fawzi , Patrick Hayden , Ivan Savov , Pranab Sen , Mark M. Wilde

The quantum capacity of thermal noise channel is studied. The extremal input state is obtained at the postulation that the coherent information is convex or concave at its vicinity. When the input energy tends to infinitive, it is verified…

Quantum Physics · Physics 2007-05-23 Xiao-yu Chen

While quantum computing can accomplish tasks that are classically intractable, the presence of noise may destroy this advantage in the absence of fault tolerance. In this work, we present a classical algorithm that runs in…

Quantum Physics · Physics 2025-10-09 Yifan F. Zhang , Su-un Lee , Liang Jiang , Sarang Gopalakrishnan

We investigate the dynamics of quantum correlations (QC) under the effects of reservoir memory, as a resource for quantum information and computation tasks. Quantum correlations of two-qubit systems are used for implementing quantum…

Quantum Physics · Physics 2022-02-17 K. G Paulson , Ekta Panwar , Subhashish Banerjee , R. Srikanth

We study the performance of two measures of non-Markovianity in detecting memory effects in two-qubit dephasing channels. By combining independent Markovian and non-Markovian noise on the qubits, our results show that the trace distance…

Quantum Physics · Physics 2016-04-06 Antti Karlsson , Henri Lyyra , Elsi-Mari Laine , Sabrina Maniscalco , Jyrki Piilo

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

Computing channel capacity is in general intractable because it is given by the limit of a sequence of optimization problems whose dimensionality grows to infinity. As a result, constant-sized characterizations of feedback or non-feedback…

Information Theory · Computer Science 2025-07-15 Eray Unsal Atay , Eitan Levin , Venkat Chandrasekaran , Victoria Kostina

For a quantum channel of additive Gaussian noise with loss, in the general case of $n$ copies input, we show that up to first order perturbation, any non-Gaussian perturbation to the product thermal state input has a less quantum…

Quantum Physics · Physics 2007-10-03 Xiao-yu Chen

When classical or quantum information is broadcast to separate receivers, there exist codes that encrypt the encoded data such that the receivers cannot recover it when performing local operations and classical communication, but they can…

Quantum Physics · Physics 2016-05-31 Cosmo Lupo , Mark M. Wilde , Seth Lloyd

When a noisy communication channel is used multiple times, the errors occurring at different times generally exhibit correlations. Classically, these correlations do not affect the evolution of individual particles: a single classical…

Quantum Physics · Physics 2021-12-07 Hlér Kristjánsson , Wenxu Mao , Giulio Chiribella

We characterize the behavior of quantum correlations under the influence of local noisy channels. Intuition suggests that such noise should be detrimental for quantumness. When considering qubit systems, we show for which channel this is…

Quantum Physics · Physics 2011-10-18 Alexander Streltsov , Hermann Kampermann , Dagmar Bruß

We study the effect of noise on the classical simulatability of quantum circuits defined by computationally tractable (CT) states and efficiently computable sparse (ECS) operations. Examples of such circuits, which we call CT-ECS circuits,…

Quantum Physics · Physics 2020-08-28 Yasuhiro Takahashi , Yuki Takeuchi , Seiichiro Tani

We present a novel approach to the study of entanglement decay, which focuses on collective properties. As an example, we investigate the entanglement decay of a two-qubit system, produced by local identical reservoirs acting on the qubits,…

Quantum Physics · Physics 2012-10-23 Karen M. Fonseca-Romero , Julián Martínez-Rincón , Carlos Viviescas

Any physical process can be represented as a quantum channel mapping an initial state to a final state. Hence it can be characterized from the point of view of communication theory, i.e., in terms of its ability to transfer information.…

Quantum Physics · Physics 2014-12-16 F. Caruso , V. Giovannetti , C. Lupo , S. Mancini

In most studies of the channel capacity of quantum channels, it is assumed that the errors in each use of the channel are independent. However, recent work has begun to investigate the effects of memory or correlations in the error. This…

Quantum Physics · Physics 2007-10-16 M. B. Plenio , S. Virmani

A recent method to certify the classical capacity of quantum communication channels is applied for general damping channels in finite dimension. The method compares the mutual information obtained by coding on the computational and a…

Quantum Physics · Physics 2020-10-23 Chiara Macchiavello , Massimiliano F. Sacchi , Tito Sacchi