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Related papers: Information capacity of quantum observable

200 papers

Transmission of classical information using quantum objects such as polarized photons is studied. The classical (Shannon) channel capacity and its relation to quantum (von Neumann) channel capacity is investigated for various receiver…

Quantum Physics · Physics 2007-05-23 Göran Einarsson

We find a strong-converse bound on the private capacity of a quantum channel assisted by unlimited two-way classical communication. The bound is based on the max-relative entropy of entanglement and its proof uses a new inequality for the…

Quantum Physics · Physics 2017-07-04 Matthias Christandl , Alexander Müller-Hermes

Entanglement-breaking channels (equivalently, measure-and-prepare channels) are an important class of quantum operations noted for their ability to destroy multipartite spatial quantum correlations. Inspired by this property, they have also…

Quantum Physics · Physics 2025-12-22 Lucas B. Vieira , Huan-Yu Ku , Costantino Budroni

We provide an overview of a canonical formalism that describes mixed quantum-classical systems in terms of statistical ensembles on configuration space, and discuss applications to measurement theory. It is shown that the formalism allows a…

Quantum Physics · Physics 2009-07-06 M Reginatto , M J W Hall

We introduce various measures of forward classical communication for bipartite quantum channels. Since a point-to-point channel is a special case of a bipartite channel, the measures reduce to measures of classical communication for…

Quantum Physics · Physics 2023-04-25 Dawei Ding , Sumeet Khatri , Yihui Quek , Peter W. Shor , Xin Wang , Mark M. Wilde

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

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

Passive environment assisted communication takes place via a quantum channel modeled as a unitary interaction between the information carrying system and an environment, where the latter is controlled by a passive helper, who can set its…

Quantum Physics · Physics 2021-12-28 Samad Khabbazi Oskouei , Stefano Mancini , Andreas Winter

The readout of a classical memory can be modelled as a problem of quantum channel discrimination, where a decoder retrieves information by distinguishing the different quantum channels encoded in each cell of the memory [S. Pirandola, Phys.…

This work investigates the application of quantum machine learning techniques for classical and quantum communication across different qubit channel models. By employing parameterized quantum circuits and a flexible channel noise model, we…

Quantum Physics · Physics 2023-07-14 Lakshika Rathi , Stephen DiAdamo , Alireza Shabani

We present an upper bound for the quantum channel capacity that is both additive and convex. Our bound can be interpreted as the capacity of a channel for high-fidelity quantum communication when assisted by a family of channels that have…

Quantum Physics · Physics 2008-08-28 Graeme Smith , John A. Smolin , Andreas Winter

We derive upper bounds on the rate of transmission of classical information over quantum channels by block codes with a given blocklength and error probability, for both entanglement-assisted and unassisted codes, in terms of a unifying…

Quantum Physics · Physics 2016-01-01 William Matthews , Stephanie Wehner

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…

Given a quantum Markovian noise model, we study the maximum dimension of a classical or quantum system that can be stored for arbitrarily large time. We show that, unlike the fixed time setting, in the limit of infinite time, the classical…

Quantum Physics · Physics 2025-02-27 Omar Fawzi , Mizanur Rahaman , Mostafa Taheri

We consider a setting where a stream of qubits is processed sequentially. We derive fundamental limits on the rate at which classical information can be transmitted using qubits that decohere as they wait to be processed. Specifically, we…

Information Theory · Computer Science 2020-08-11 Prabha Mandayam , Krishna Jagannathan , Avhishek Chatterjee

We investigate whether the use of a noiseless, classical feedback channel will increase the capacity of a quantum discrete memoryless channel to transmit classical information. This problem has been previously analyzed by Bowen and…

Quantum Physics · Physics 2007-05-23 Andrew Skeen

We investigate the transmission of both classical and quantum information between two arbitrary observers in globally hyperbolic spacetimes using a quantum field as a communication channel. The field is supposed to be in some arbitrary…

General Relativity and Quantum Cosmology · Physics 2016-05-12 Andre G. S. Landulfo

The computational problem of distinguishing two quantum channels is central to quantum computing. It is a generalization of the well-known satisfiability problem from classical to quantum computation. This problem is shown to be…

Quantum Physics · Physics 2009-09-24 Bill Rosgen

The set of quantum Gaussian channels acting on one bosonic mode can be classified according to the action of the group of Gaussian unitaries. We look for bounds on the classical capacity for channels belonging to such a classification.…

Quantum Physics · Physics 2011-03-03 Cosmo Lupo , Stefano Pirandola , Paolo Aniello , Stefano Mancini

We test a general method to detect lower bounds of the quantum channel capacity for two-qubit correlated channels. We consider in particular correlated dephasing, depolarising and amplitude damping channels. We show that the method is…

Quantum Physics · Physics 2016-12-01 Chiara Macchiavello , Massimiliano F. Sacchi