English
Related papers

Related papers: Capacity Bounds via Operator Space Methods

200 papers

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

Transmitting data reliably over noisy communication channels is one of the most important applications of information theory, and well understood when the channel is accurately modelled by classical physics. However, when quantum effects…

We prove that the classical capacity of an arbitrary quantum channel assisted by a free classical feedback channel is bounded from above by the maximum average output entropy of the quantum channel. As a consequence of this bound, we…

Quantum Physics · Physics 2020-09-15 Dawei Ding , Yihui Quek , Peter W. Shor , Mark M. Wilde

The capacity of noisy quantum channels characterizes the highest rate at which information can be reliably transmitted and it is therefore of practical as well as fundamental importance. Capacities of classical channels are computed using…

Quantum Physics · Physics 2021-07-02 Navneeth Ramakrishnan , Raban Iten , Volkher B. Scholz , Mario Berta

Quantum channel capacities are fundamental to quantum information theory. Their definition, however, does not limit the computational resources of sender and receiver. In this work, we initiate the study of computational quantum capacities.…

Quantum Physics · Physics 2026-01-23 Johannes Jakob Meyer , Jacopo Rizzo , Asad Raza , Lorenzo Leone , Sofiene Jerbi , Jens Eisert

We show the equivalence of two different notions of quantum channel capacity: that which uses the entanglement fidelity as its criterion of success in transmission, and that which uses the minimum fidelity of pure states in a subspace of…

Quantum Physics · Physics 2016-11-18 H. Barnum , E. Knill , M. A. Nielsen

The applications of the general formulae of channel capacity developed in the quantum information theory to evaluation of information transmission capacity of optical channel are interesting subjects. In this review paper, we will point out…

Quantum Physics · Physics 2007-05-23 Masaki Sohma , Osamu Hirota

The capacity of a channel is known to be equivalent to the highest rate at which it can generate entanglement. Analogous to entanglement, the notion of a causality measure characterises the temporal aspect of quantum correlations. Despite…

Quantum Physics · Physics 2020-02-24 Robert Pisarczyk , Zhikuan Zhao , Yingkai Ouyang , Vlatko Vedral , Joseph F. Fitzsimons

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…

The optimal performance of a communication network is limited not only by the quality of point-to-point channels, but by the efficacy of its constituent technologies. Understanding the limits of quantum networks requires an understanding of…

Quantum Physics · Physics 2022-07-13 Cillian Harney , Stefano Pirandola

An upper limit is given to the amount of quantum information that can be transmitted reliably down a noisy, decoherent quantum channel. A class of quantum error-correcting codes is presented that allow the information transmitted to attain…

Quantum Physics · Physics 2009-10-30 Seth Lloyd

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

The optimal rate at which information can be sent through a quantum channel when the transmitted signal must simultaneously carry some minimum amount of energy is characterized. To do so, we introduce the quantum-classical analogue of the…

Quantum Physics · Physics 2025-01-10 Bishal Kumar Das , Lav R. Varshney , Vaibhav Madhok

Quantum information processing exploits the quantum nature of information. It offers fundamentally new solutions in the field of computer science and extends the possibilities to a level that cannot be imagined in classical communication…

Quantum Physics · Physics 2018-01-09 Laszlo Gyongyosi , Sandor Imre , Hung Viet Nguyen

In this work we improve the quantum communication rates of various quantum channels of interest using permutation-invariant quantum codes. We focus in particular on parametrized families of quantum channels and aim to improve bounds on…

Quantum Physics · Physics 2025-08-14 Sujeet Bhalerao , Felix Leditzky

Capacities of quantum channels are fundamental quantities in the theory of quantum information. A desirable property is the additivity for a capacity. However, this cannot be achieved for a few quantities that have been established as…

Quantum Physics · Physics 2025-05-20 D. -S. Wang

Following initial work by Gregoratti and Werner [J. Mod. Optics 50, 913-933, 2003 and quant-ph/0403092] and Hayden and King [quant-ph/0409026], we study the problem of the capacity of a quantum channel assisted by a "friendly (channel)…

Quantum Physics · Physics 2017-08-01 Andreas Winter

Optical channels, such as fibers or free-space links, are ubiquitous in today's telecommunication networks. They rely on the electromagnetic field associated with photons to carry information from one point to another in space. As a result,…

Quantum Physics · Physics 2015-06-18 V. Giovannetti , R. Garcia-Patron , N. J. Cerf , A. S. Holevo

An expression is derived characterizing the set of admissible rate pairs for simultaneous transmission of classical and quantum information over a given quantum channel, generalizing both the classical and quantum capacities of the channel.…

Quantum Physics · Physics 2007-05-23 I. Devetak , P. W. Shor

We analyze the quantum capacity of a unital quantum channel, using ideas from the proof of near-optimality of Petz recovery map [Barnum and Knill 2000] and give an upper bound on the quantum capacity in terms of regularized output $2$-norm…

Quantum Physics · Physics 2018-03-07 Anurag Anshu