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Related papers: Entropic bounds on coding for noisy quantum channe…

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We give a short proof that the coherent information is an achievable rate for the transmission of quantum information through a noisy quantum channel. Our method is to produce random codes by performing a unitarily covariant projective…

Quantum Physics · Physics 2016-11-17 Patrick Hayden , Michal Horodecki , Andreas Winter , Jon Yard

The two-way capacities of quantum channels determine the ultimate entanglement and secret-key distribution rates achievable by two distant parties that are connected by a noisy transmission line, in absence of quantum repeaters. Since…

Quantum Physics · Physics 2025-01-27 Francesco Anna Mele , Ludovico Lami , Vittorio Giovannetti

Quantum communication is an important branch of quantum information science, promising unconditional security to classical communication and providing the building block of a future large-scale quantum network. Noise in realistic quantum…

Quantum Physics · Physics 2020-01-24 Kyungjoo Noh , Stefano Pirandola , Liang Jiang

Coding theorems and (strong) converses for memoryless quantum communication channels and quantum sources are proved: for the quantum source the coding theorem is reviewed, and the strong converse proven. For classical information…

Quantum Physics · Physics 2007-05-23 Andreas Winter

We study the problem of transmission of information over classical and classical-quantum channels in the one-shot regime where the underlying codes are constrained to be group codes. In the achievability part, we introduce a new input…

Information Theory · Computer Science 2024-06-21 James Chin-Jen Pang , Sandeep Pradhan , Hessam Mahdavifar

We study error correction type protocols in which a quantum channel encodes logical information into an enlarged Hilbert space. Specifically, we consider channels realized by one dimensional random noisy quantum circuits with spatially…

Quantum Physics · Physics 2026-03-24 Arman Sauliere , Guglielmo Lami , Pedro Ribeiro , Andrea De Luca , Jacopo De Nardis

While a positive operator valued measure gives the probabilities in a quantum measurement, an instrument gives both the probabilities and the a posteriori states. By interpreting the instrument as a quantum channel and by using the…

Quantum Physics · Physics 2007-05-23 Alberto Barchielli , Giancarlo Lupieri

Sending quantum information reliably over long distances is a central challenge in quantum technology in general, and in quantum optics in particular, since most quantum communication relies on optical fibres or free-space links. Here, we…

Quantum Physics · Physics 2026-02-27 Tobias Rippchen , Ludovico Lami , Gerardo Adesso , Mario Berta

Quantum capacity gives the fundamental limit of information transmission through a channel. However, evaluating the quantum capacities of a continuous-variable bosonic quantum channel, as well as finding an optimal code to achieve the…

Quantum Physics · Physics 2025-10-03 Adam Taylor , Michael Hanks , Hyukjoon Kwon , M. S. Kim

We discuss the capacity of quantum channels for information transmission and storage. Quantum channels have dual uses: they can be used to transmit known quantum states which code for classical information, and they can be used in a purely…

Quantum Physics · Physics 2008-12-18 C. Adami , N. J. Cerf

We obtain a lower bound on the maximum number of qubits, $Q^{n, \epsilon}(\mathcal{N})$, which can be transmitted over $n$ uses of a quantum channel $\mathcal{N}$, for a given non-zero error threshold $\epsilon$. To obtain our result, we…

Quantum Physics · Physics 2024-12-31 Salman Beigi , Nilanjana Datta , Felix Leditzky

The squashed entanglement of a quantum channel is an additive function of quantum channels, which finds application as an upper bound on the rate at which secret key and entanglement can be generated when using a quantum channel a large…

Quantum Physics · Physics 2016-04-26 Kaushik P. Seshadreesan , Masahiro Takeoka , Mark M. Wilde

We show that no source encoding is needed in the definition of the capacity of a quantum channel for carrying quantum information. This allows us to use the coherent information maximized over all sources and and block sizes, but not…

Quantum Physics · Physics 2011-07-19 H. Barnum , J. A. Smolin , B. M. Terhal

This paper finds new tight finite-blocklength bounds for the best achievable lossy joint source-channel code rate, and demonstrates that joint source-channel code design brings considerable performance advantage over a separate one in the…

Information Theory · Computer Science 2014-02-05 Victoria Kostina , Sergio Verdú

We study the information transmission through a quantum channel, defined over a continuous alphabet and losing its energy en route, in presence of correlated noise among different channel uses. We then show that entangled inputs improve the…

Quantum Physics · Physics 2009-11-11 Giovanna Ruggeri , Giulio Soliani , Vittorio Giovannetti , Stefano Mancini

Capacity of a quantum channel characterizes the limits of reliable communication through a noisy quantum channel. This fundamental information theoretic question is very well studied specially in the setting of many independent uses of the…

Quantum Physics · Physics 2019-03-19 Anurag Anshu , Rahul Jain , Naqueeb Ahmad Warsi

Maximally entangled states--a resource for quantum information processing--can only be shared through noiseless quantum channels, whereas in practice channels are noisy. Here we ask: Given a noisy quantum channel, what is the maximum…

Quantum Physics · Physics 2018-07-17 Rajarshi Pal , Somshubhro Bandyopadhyay , Sibasish Ghosh

We investigate quantum teleportation through noisy quantum channels by solving analytically and numerically a master equation in the Lindblad form. We calculate the fidelity as a function of decoherence rates and angles of a state to be…

Quantum Physics · Physics 2009-11-07 Sangchul Oh , Soonchil Lee , Hai-woong Lee

For any quantum transmission line, with smaller output dimension than its input, the number of classical symbols that can be reliably encoded is strictly suboptimal. In other words, if the channel outputs a lesser number of symbols than it…

Quantum Physics · Physics 2025-09-12 Snehasish Roy Chowdhury , Sutapa Saha , Subhendu B. Ghosh , Ranendu Adhikary , Tamal Guha

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