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Related papers: Capacities of lossy bosonic memory channels

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We derive the general formula for the capacity of a noiseless quantum channel assisted by an arbitrary amount of noisy entanglement. In this capacity formula, the ratio of the quantum mutual information and the von Neumann entropy of the…

Quantum Physics · Physics 2007-05-23 Michal Horodecki , Pawel Horodecki , Ryszard Horodecki , Debbie Leung , Barbara Terhal

Quantum neural networks form one pillar of the emergent field of quantum machine learning. Here, quantum generalisations of classical networks realizing associative memories - capable of retrieving patterns, or memories, from corrupted…

Quantum Physics · Physics 2025-03-28 Lukas Bödeker , Eliana Fiorelli , Markus Müller

In this paper, using the notion of nonlinear coherent states, we define a deformed bosonic dephasing channel modelling the impact of a Kerr medium on a quantum state, as it occurs, for instance, in quantum communication based on optical…

Quantum Physics · Physics 2022-11-17 Shahram Dehdashti , Janis Notzel , Peter van Loock

The property of the optimal signal ensembles of entanglement assisted channel capacity is studied. A relationship between entanglement assisted channel capacity and one-shot capacity of unassisted channel is obtained. The data processing…

Quantum Physics · Physics 2009-11-10 Heng Fan

The capacity of a classical-quantum channel (or in other words the classical capacity of a quantum channel) is considered in the most general setting, where no structural assumptions such as the stationary memoryless property are made on a…

Quantum Physics · Physics 2016-11-17 Masahito Hayashi , Hiroshi Nagaoka

Prior entanglement between sender and receiver, which exactly doubles the classical capacity of a noiseless quantum channel, can increase the classical capacity of some noisy quantum channels by an arbitrarily large constant factor…

Quantum Physics · Physics 2009-01-23 Charles H. Bennett , Peter W. Shor , John A. Smolin , Ashish V. Thapliyal

Quantum queue-channels arise naturally in the context of buffering in quantum networks, wherein the noise suffered by the quantum states depends on the time spent waiting in the buffer. It has been shown that the upper-bound on the…

We derive exact analytical expressions for the quantum capacity of a broad subclasses of generalized dephasing channels of the form $\Lambda(\rho)=(1-x)\rho + x D(\rho)$, where $D(\rho)$ represents a structured decoherence process. These…

Quantum Physics · Physics 2025-11-26 Shayan Roofeh , Vahid Karimipour

We derive explicit formulas for the capacity of multimode quantum Gaussian channels which serve as a fundamental model for optical version of multiple-input multiple-output channels. We show that it is always optimal to increase the number…

Quantum Physics · Physics 2026-05-20 Maria Popławska , Marcin Jarzyna

This paper was presented in poster form at and in the proceedings of the QCMC 2008. It is a summary of a fuller paper to appear separately. The classical product state capacity of a noisy quantum channel with memory is investigated. A…

Quantum Physics · Physics 2012-08-16 I. Akhalwaya , J. Wouters , M. Fannes , F. Petruccione

Consider communication over a channel whose probabilistic model is completely unknown vector-wise and is not assumed to be stationary. Communication over such channels is challenging because knowing the past does not indicate anything about…

Information Theory · Computer Science 2013-03-21 Yuval Lomnitz , Meir Feder

The maximal amount of information which is reliably transmitted over two uses of general Pauli channels with memory is proven to be achieved by maximally entangled states beyond some memory threshold. In particular, this proves a conjecture…

Quantum Physics · Physics 2011-11-09 D. Daems

The quantum channel capacity gives the ultimate limit for the rate at which quantum data can be reliably transmitted through a noisy quantum channel. Degradable quantum channels are among the few channels whose quantum capacities are known.…

Quantum Physics · Physics 2011-03-31 Markus Grassl , Zhengfeng Ji , Zhaohui Wei , Bei Zeng

We construct concatenated capacity-achieving quantum codes for noisy optical quantum channels. We demonstrate that the error-probability of capacity-achieving quantum polar encoding can be reduced by the proposed low-complexity…

Quantum Physics · Physics 2013-02-14 Laszlo Gyongyosi , Sandor Imre

Time-varying quantum channels are essential for modeling realistic quantum systems with evolving noise properties. Here, we consider Gaussian lossy channels varying from one use to another and we employ neural networks to classify, regress,…

The full solution of the optimization problem giving the Gaussian capacity of the single-mode fiducial Gaussian quantum channel is provided. Since it was shown that the Gaussian capacity of an arbitrary (phase-sensitive or insensitive)…

Quantum Physics · Physics 2016-09-19 Joachim Schäfer , Evgueni Karpov , Oleg V. Pilyavets , Nicolas J. Cerf

Previous work on the classical information capacities of bosonic channels has established the capacity of the single-user pure-loss channel, bounded the capacity of the single-user thermal-noise channel, and bounded the capacity region of…

Quantum Physics · Physics 2009-11-13 Saikat Guha , Jeffrey H. Shapiro , Baris I. Erkmen

We calculate numerically the capacity of a lossy photon channel assuming photon number resolving detection at the output. We consider scenarios of input Fock and coherent states ensembles and show that the latter always exhibits worse…

Quantum Physics · Physics 2021-08-30 Karol Łukanowski , Marcin Jarzyna

One of the most sought-after goals in experimental quantum communication is the implementation of a quantum repeater. The performance of quantum repeaters can be assessed by comparing the attained rate with the quantum and private capacity…

Quantum Physics · Physics 2016-06-27 Kenneth Goodenough , David Elkouss , Stephanie Wehner

Bosonic or continuous-variable coding is a field concerned with robust quantum information processing and communication with electromagnetic signals or mechanical modes. I review bosonic quantum memories, characterizing them as either…

Quantum Physics · Physics 2025-01-28 Victor V. Albert
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