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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

Transmitting data reliably over noisy communication channels is one of the most important applications of information theory, and well understood when the channel is accurately modelled by classical physics. However, when quantum effects…

Entangled inputs can enhance the capacity of quantum channels, this being one of the consequences of the celebrated result showing the non-additivity of several quantities relevant for quantum information science. In this work, we answer…

Quantum Physics · Physics 2015-05-20 Fernando G. S. L. Brandao , Jens Eisert , Michal Horodecki , Dong Yang

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

Estimating the information transmission capability of a quantum channel remains one of the fundamental problems in quantum information processing. In contrast to classical channels, the information-carrying capability of quantum channels is…

Quantum Physics · Physics 2024-07-26 Aditya Nema , Ananda G. Maity , Sergii Strelchuk , David Elkouss

We investigate super dense coding in the presence of noise, i.e. the subsystems of the entangled resource state have to pass a noisy unital quantum channel between the sender and the receiver. We discuss explicitly the case of Pauli…

Quantum Physics · Physics 2015-05-18 Zahra Shadman , Hermann Kampermann , Chiara Macchiavello , Dagmar Bruss

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

We address the classical capacity of a quantum bosonic memory channel with additive noise, subject to an input energy constraint. The memory is modeled by correlated noise emerging from a Gauss-Markov process. Under reasonable assumptions,…

Quantum Physics · Physics 2009-12-08 Joachim Schäfer , David Daems , Evgueni Karpov , Nicolas J. Cerf

We present an effcient experimental procedure that certifies non vanishing quantum capacities for qubit noisy channels. Our method is based on the use of a fixed bipartite entangled state, where the system qubit is sent to the channel…

Dynamics of many-qubit systems, that may correspond to computational processing with quantum systems, can be efficiently and generally approximated by a sequence of two- and single-qubit gates. In practical applications, however, a quantum…

Quantum Physics · Physics 2018-12-06 Joonwoo Bae , Tanmay Singal

We extend a recent method to detect lower bounds to the quantum capacity of quantum communication channels by considering realistic scenarios with general input probe states and arbitrary detection procedures at the output. Realistic…

Quantum Physics · Physics 2018-01-09 Chiara Macchiavello , Massimiliano F. Sacchi

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

We introduce potential capacities of quantum channels in an operational way and provide upper bounds for these quantities, which quantify the ultimate limit of usefulness of a channel for a given task in the best possible context.…

Quantum Physics · Physics 2016-02-17 Andreas Winter , Dong Yang

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

Quantum communication theory explores the implications of quantum mechanics to the tasks of information transmission. Many physical channels can be formally described as quantum Gaussian operations acting on bosonic quantum states.…

Quantum Physics · Physics 2015-05-14 Andrea Mari , Vittorio Giovannetti , Alexander S. Holevo

Quantum kernel methods have been widely recognized as one of promising quantum machine learning algorithms that have potential to achieve quantum advantages. In this paper, we theoretically characterize the power of noisy quantum kernels…

Quantum Physics · Physics 2024-02-01 Yabo Wang , Bo Qi , Xin Wang , Tongliang Liu , Daoyi Dong

We study the capacity of d-dimensional quantum channels with memory modeled by correlated noise. We show that, in agreement with previous results on Pauli qubit channels, there are situations where maximally entangled input states achieve…

Quantum Physics · Physics 2007-05-23 E. Karpov , D. Daems , N. J. Cerf

We construct a class of quantum channels in arbitrary dimensions for which entanglement improves the performance of the channel. The channels have correlated noise and when the level of correlation passes a critical value we see a sharp…

Quantum Physics · Physics 2009-11-13 V. Karimipour , L. Memarzadeh

Information theory establishes the ultimate limits on performance for noisy communication systems [Shannon48]. An accurate model of a physical communication device must include quantum effects, but typically including these makes the theory…

Quantum Physics · Physics 2013-12-20 Graeme Smith , John A. Smolin

We present an experimental method to detect lower bounds to the quantum capacity of two-qubit communication channels. We consider an implementation with polarisation degrees of freedom of two photons and report on the efficiency of such a…