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Related papers: Algorithmic complexity of quantum capacity

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A wide variety of communication channels employ the quantized electromagnetic field to convey information. Their communication capacity crucially depends on losses associated to spatial characteristics of the channel such as diffraction and…

Quantum Physics · Physics 2012-06-21 Cosmo Lupo , Vittorio Giovannetti , Stefano Pirandola , Stefano Mancini , Seth Lloyd

The amount of information transmissible through a communications channel is determined by the noise characteristics of the channel and by the quantities of available transmission resources. In classical information theory, the amount of…

Quantum Physics · Physics 2009-11-10 Mikio Fujiwara , Masahiro Takeoka , Jun Mizuno , Masahide Sasaki

In this paper we show how \emph{the metric theory of tensor products} developed by Grothendieck perfectly fits in the study of channel capacities, a central topic in \emph{Shannon's information theory}. Furthermore, in the last years…

Functional Analysis · Mathematics 2015-02-10 Marius Junge , Carlos Palazuelos

We consider quantum channels with one sender and two receivers, used in several different ways for the simultaneous transmission of independent messages. We begin by extending the technique of superposition coding to quantum channels with a…

Quantum Physics · Physics 2011-10-25 Jon Yard , Patrick Hayden , Igor Devetak

Quantum communication networks (QCNs) utilize quantum mechanics for secure information transmission, but the reliance on fragile and expensive photonic quantum resources renders QCN resource optimization challenging. Unlike prior QCN works…

Networking and Internet Architecture · Computer Science 2024-04-30 Mahdi Chehimi , Christina Chaccour , Christo Kurisummoottil Thomas , Walid Saad

The quantum capacity of a memoryless channel is often used as a single figure of merit to characterize its ability to transmit quantum information coherently. The capacity determines the maximal rate at which we can code reliably over…

Quantum Physics · Physics 2016-05-10 Marco Tomamichel , Mario Berta , Joseph M. Renes

In recent years, new algorithms and cryptographic protocols based on the laws of quantum physics have been designed to outperform classical communication and computation. We show that the quantum world also opens up new perspectives in the…

Quantum Physics · Physics 2010-07-06 S. Perseguers , M. Lewenstein , A. Acín , J. I. Cirac

The quantum capacity captures the value of a quantum channel for transmitting quantum information, establishing the fundamental limits on quantum communication. In spite of its central role in quantum information theory, the quantum…

Quantum computing allows for the potential of significant advancements in both the speed and the capacity of widely used machine learning techniques. Here we employ quantum algorithms for the Hopfield network, which can be used for pattern…

Quantum Physics · Physics 2018-10-10 Patrick Rebentrost , Thomas R. Bromley , Christian Weedbrook , Seth Lloyd

Artificial neural networks have been proposed as potential algorithms that could benefit from being implemented and run on quantum computers. In particular, they hold promise to greatly enhance Artificial Intelligence tasks, such as image…

Quantum Physics · Physics 2021-03-04 Stefano Mangini , Francesco Tacchino , Dario Gerace , Chiara Macchiavello , Daniele Bajoni

Thermodynamics imposes restrictions on what state transformations are possible. In the macroscopic limit of asymptotically many independent copies of a state---as for instance in the case of an ideal gas---the possible transformations…

Quantum Physics · Physics 2019-11-14 Philippe Faist , Mario Berta , Fernando Brandão

Quantum channel capacities give the fundamental performance limits for information flow over a communication channel. However, the prevalence of superadditivity is a major obstacle to understanding capacities, both quantitatively and…

Quantum Physics · Physics 2025-09-10 Graeme Smith , Peixue Wu

The complexity of quantum computation remains poorly understood. While physicists attempt to find ways to create quantum computers, we still do not have much evidence one way or the other as to how useful these machines will be. The tools…

Quantum Physics · Physics 2007-05-23 Lance Fortnow

Quantum amplifier channels are at the core of several physical processes. Not only do they model the optical process of spontaneous parametric down-conversion, but the transformation corresponding to an amplifier channel also describes the…

Quantum Physics · Physics 2017-02-02 Haoyu Qi , Mark M. Wilde

We investigate the capacity of bosonic quantum channels for the transmission of quantum information. Achievable rates are determined from measurable moments of the channel by showing that every channel can asymptotically simulate a Gaussian…

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

Here, we study the capacity of a quantum channel, assuming linear optical encoding, as a function of available photons and optical modes. First, we observe that substantial improvement is made possible by not restricting ourselves to a…

Quantum Physics · Physics 2015-08-12 Jake A. Smith , Dmitry B. Uskov , Lev Kaplan

We consider the problem of implementing two-party interactive quantum communication over noisy channels, a necessary endeavor if we wish to fully reap quantum advantages for communication. For an arbitrary protocol with $n$ messages,…

Quantum Physics · Physics 2020-01-10 Debbie Leung , Ashwin Nayak , Ala Shayeghi , Dave Touchette , Penghui Yao , Nengkun Yu

A system of two closely spaced atoms interacting through a vacuum electromagnetic field is considered. It is demonstrated that radiative decay in such a system resulting from photon exchange gives rise to a definite amount of information…

Quantum Physics · Physics 2007-05-23 Boris Grishanin , Victor Zadkov

Quantum communication holds a promise for absolutely secure transmission of secret messages and faithful transfer of unknown quantum states. Photonic channels appear to be very attractive for physical implementation of quantum…

Quantum Physics · Physics 2009-11-07 Lu-Ming Duan , Mikhail Lukin , Ignacio Cirac , Peter Zoller

A class of problems in quantum information theory, having an elementary formulation but still resisting solution, concerns the additivity properties of various quantities characterizing quantum channels, notably the "classical capacity",…

Mathematical Physics · Physics 2007-05-23 G. G. Amosov , A. S. Holevo , R. F. Werner