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Related papers: Capacities of Quantum Amplifier Channels

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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

Linear parametric amplification is a key operation in information processing. Our interest here is quantum-limited parametric amplification, $i.e.$, amplification of quantum signals while adding the minimum amount of noise allowed by…

Quantum Physics · Physics 2018-07-10 Ananda Roy , Michel Devoret

We consider the transfer of classical and quantum information through a memory amplitude damping channel. Such a quantum channel is modeled as a damped harmonic oscillator, the interaction between the information carriers - a train of…

Quantum Physics · Physics 2012-06-15 A. D'Arrigo , G. Benenti , G. Falci

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

The design of error-correcting codes used in modern communications relies on information theory to quantify the capacity of a noisy channel to send information [1]. This capacity can be expressed using the mutual information between input…

Quantum Physics · Physics 2019-07-17 M. B. Hastings

The quantum capacity of thermal noise channel is studied. The extremal input state is obtained at the postulation that the coherent information is convex or concave at its vicinity. When the input energy tends to infinitive, it is verified…

Quantum Physics · Physics 2007-05-23 Xiao-yu Chen

The communication complexity of a quantum channel is the minimal amount of classical communication required for classically simulating a process of state preparation, transmission through the channel and subsequent measurement. It…

Quantum Physics · Physics 2012-09-14 Alberto Montina

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

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

Quantum capacities are fundamental quantities that are notoriously hard to compute and can exhibit surprising properties such as superadditivity. Thus, a vast amount of literature is devoted to finding tight and computable bounds on these…

Quantum Physics · Physics 2023-03-02 Christoph Hirche , Felix Leditzky

Communication rates over quantum channels can be boosted by entanglement, via superadditivity phenomena or entanglement assistance. Superadditivity refers to the capacity improvement from entangling inputs across multiple channel uses.…

Quantum Physics · Physics 2022-03-14 Haowei Shi , Quntao Zhuang

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

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

Classical capacity of unital qubit channels is well known, whereas that of nonunital qubit channels is not. We find lower and upper bounds on classical capacity of nonunital qubit channels by using a recently developed decomposition…

Quantum Physics · Physics 2019-03-22 Sergey N. Filippov

The discrete memoryless interference channel is modelled as a conditional probability distribution with two outputs depending on two inputs and has widespread applications in practical communication scenarios. In this paper, we introduce…

Quantum Physics · Physics 2015-03-19 Ivan Savov , Omar Fawzi , Mark M. Wilde , Pranab Sen , Patrick Hayden

Entanglement shared between the two ends of a quantum communication channel has been shown to be a useful resource in increasing both the quantum and classical capacities for these channels. The entanglement-assisted capacities were derived…

Quantum Physics · Physics 2009-11-07 Garry Bowen

Shannon's channel coding theorem describes the maximum possible rate of reliable information transfer through a classical noisy communication channel. It, together with the source coding theorem, characterizes lossless channel communication…

Quantum Physics · Physics 2021-05-17 Sristy Agrawal , Rajashik Tarafder , Graeme Smith , Arup Roy , Manik Banik

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

Quantum reading refers to the task of reading out classical information stored in a read-only memory device. In any such protocol, the transmitter and receiver are in the same physical location, and the goal of such a protocol is to use…

Quantum Physics · Physics 2019-11-04 Siddhartha Das , Mark M. Wilde

Evaluating the quantum capacity of quantum channels is an important but difficult problem, even for channels of low input and output dimension. Smith and Smolin showed that the quantum capacity of the Clifford-twirl of a qubit amplitude…

Quantum Physics · Physics 2021-10-12 Yingkai Ouyang