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By considering quantum computation as a communication process, we relate its efficiency to a communication capacity. This formalism allows us to rederive lower bounds on the complexity of search algorithms. It also enables us to link the…

Quantum Physics · Physics 2009-11-06 S. Bose , L. Rallan , V. Vedral

Current advancements in communication equipment demand the investigation of classical information transfer over quantum channels, by encompassing realistic scenarios in finite dimensions. To address this issue, we develop a framework for…

Quantum Physics · Physics 2026-01-08 Sudipta Mondal , Pritam Halder , Saptarshi Roy , Aditi Sen De

We analyze the quantum binary adder channel, i.e. the quantum generalization of the classical, and well-studied, binary adder channel: in this model qubits rather than classical bits are transmitted. This of course is as special case of the…

Quantum Physics · Physics 2007-05-23 Gleb V. Klimovitch , Andreas Winter

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

This paper explores communication over a two-sender, two-receiver classical interference channel, enhanced by the availability of entanglement resources between transmitters. The central contributions are an inner and outer bound on the…

Quantum Physics · Physics 2025-01-24 Jonas Hawellek , Athin Mohan , Hadi Aghaee , Christian Deppe

Applications of the quantum switch on quantum channels have recently become a topic of intense discussion. In the present work, we show that some useless (for communication) channels may provide useful communication under the action of…

Quantum Physics · Physics 2023-04-11 Arindam Mitra , Himanshu Badhani , Sibasish Ghosh

Multiplexing services as a key communication technique to effectively combine multiple signals into one signal and transmit over a shared medium. Multiplexing can increase the channel capacity by requiring more resources on the transmission…

Information Theory · Computer Science 2017-12-27 Chunlin Ji , Ruopeng Liu

One of the most surprising recent results in quantum Shannon theory is the superactivation of the quantum capacity of a quantum channel. This phenomenon has its roots in the extreme violation of additivity of the channel capacity and…

Quantum Physics · Physics 2012-08-28 Laszlo Gyongyosi , Sandor Imre

Finding exponential separation between quantum and classical information tasks is like striking gold in quantum information research. Such an advantage is believed to hold for quantum computing but is proven for quantum communication…

Motivated by results in optical communications, where the performance can degrade dramatically if the transmit power is sufficiently increased, the channel capacity is characterized for various kinds of memoryless vector channels. It is…

Information Theory · Computer Science 2015-03-20 Erik Agrell

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

We demonstrate superadditivity of one-shot zero-error classical capacity in an asymmetric communication setting where a noisy classical channel is used in parallel with a perfect quantum channel. Each channel individually supports only a…

Quantum Physics · Physics 2026-02-10 Ambuj , Anushko Chattopadhyay , Kunika Agarwal , Rakesh Das , Amit Mukherjee

Quantum network is the key to enable distributed quantum information processing. As the single-link communication rate decays exponentially with the distance, to enable reliable end-to-end quantum communication, the number of nodes needs to…

Quantum Physics · Physics 2021-08-17 Quntao Zhuang , Bingzhi Zhang

A direct proof of the relation between the one-shot classical capacity and the minimal output entropy for covariant quantum channels is suggested. The structure of covariant channels is described in some detail. A simple proof of a general…

Quantum Physics · Physics 2007-05-23 A. S. Holevo

A new model of quantum computation is considered, in which the connections between gates are programmed by the state of a quantum register. This new model of computation is shown to be more powerful than the usual quantum computation, e. g.…

Quantum Physics · Physics 2013-05-27 Timoteo Colnaghi , Giacomo Mauro D'Ariano , Paolo Perinotti , Stefano Facchini

Quantum information processing technology offers several communication strategies, which offer capacity advantages over classical technologies. However, advantages typically arise only in very particular communication scenarios which are of…

Quantum Physics · Physics 2024-02-26 Simon Sekavčnik , Janis Nötzel

The quantum capacity of degradable quantum channels has been proven to be additive. On the other hand, there is no general rule for the behavior of quantum capacity for non-degradable quantum channels. We introduce the set of partially…

Quantum Physics · Physics 2016-11-15 Laszlo Gyongyosi

Communication in a network generally takes place through a sequence of intermediate nodes connected by communication channels. In the standard theory of communication, it is assumed that the communication network is embedded in a classical…

We exhibit discrete memoryless quantum channels whose quantum capacity assisted by two-way classical communication, $Q_2$, exceeds their unassisted one-shot Holevo capacity $C_H$. These channels may be thought of as having a data input and…

Quantum Physics · Physics 2007-05-23 Charles H. Bennett , Igor Devetak , Peter W. Shor , John A. Smolin

The optimal rate of reliable communication over a quantum channel can be enhanced by pre-shared entanglement. Whereas the enhancement may be unbounded in infinite-dimensional settings even when the input power is constrained, a…