English
Related papers

Related papers: Quantum Capacities of Channels with small Environm…

200 papers

Optimization methods aimed at estimating the capacities of a general Gaussian channel are developed. Specifically evaluation of classical capacity as maximum of the Holevo information is pursued over all possible Gaussian encodings for the…

Quantum Physics · Physics 2012-09-12 Oleg V. Pilyavets , Cosmo Lupo , Stefano Mancini

The quantum capacity of a pure quantum channel and that of classical-quantum-classical channel are discussed in detail based on the fully quantum mechanical mutual entropy. It is proved that the quantum capacity generalizes the so-called…

Quantum Physics · Physics 2007-05-23 Masanori Ohya , Igor V. Volovich

We consider a molecular channel, in which messages are encoded to the frequency of objects (or concentration of molecules) in a pool, and whose output during reading time is a noisy version of the input frequencies, as obtained by sampling…

Information Theory · Computer Science 2024-05-14 Yuval Gerzon , Ilan Shomorony , Nir Weinberger

The primary objective of quantum Shannon theory is to evaluate the capacity of quantum channels. In spite of the existence of rigorous coding theorems that quantify the transmission of information through quantum channels, superadditivity…

Quantum Physics · Physics 2024-01-17 Rajiuddin Sk , Prasanta K. Panigrahi

This paper provides new insight into the classical problem of determining both the capacity of the discrete-time channel with uniform output quantization and the capacity achieving input distribution. It builds on earlier work by Gallager…

Information Theory · Computer Science 2009-01-19 Yiyue Wu , Linda M. Davis , Robert Calderbank

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

A quantum channel physically is a unitary interaction between the information carrying system and an environment, which is initialized in a pure state before the interaction. Conventionally, this state, as also the parameters of the…

Quantum Physics · Physics 2016-10-25 Siddharth Karumanchi , Stefano Mancini , Andreas Winter , Dong Yang

This paper demonstrates fundamental limits of sensor networks for detection problems where the number of hypotheses is exponentially large. Such problems characterize many important applications including detection and classification of…

Information Theory · Computer Science 2016-11-17 Yaron Rachlin , Rohit Negi , Pradeep Khosla

With the rapid deployment of quantum computers and quantum satellites, there is a pressing need to design and deploy quantum and hybrid classical-quantum networks capable of exchanging classical information. In this context, we conduct the…

Quantum Physics · Physics 2023-06-29 Indrakshi Dey , Harun Siljak , Nicola Marchetti

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

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

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

A direct proof of the relation between the one-shot classical capacity and the minimal output entropy for covariant quantum channels is suggested. The structure of covariant channels is described in some detail. A simple proof of a general…

Quantum Physics · Physics 2007-05-23 A. S. Holevo

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

The study of quantum channels is the fundamental field and promises wide range of applications, because any physical process can be represented as a quantum channel transforming an initial state into a final state. Inspired by the method…

Quantum Physics · Physics 2017-06-27 Shi-Jie Wei , Tao Xin , Gui-Lu Long

We study the quantum capacity of continuous variable dephasing channel, which is a notable example of non-Gaussian quantum channel. We prove that a single letter formula applies. We then consider input energy restriction and show that by…

Quantum Physics · Physics 2021-03-24 Amir Arqand , Laleh Memarzadeh , Stefano Mancini

We study the communication capacities of bosonic broadband channels in the presence of different sources of noise. In particular we analyze lossy channels in presence of white noise and thermal bath. In this context, we provide a numerical…

Quantum Physics · Physics 2009-11-10 Vittorio Giovannetti , Seth Lloyd , Lorenzo Maccone , Peter W. Shor

Using the axiomatic definition of the coherence measure, such as the $l_{1}$ norm and the relative entropy, we study the phenomena of two-qubit system quantum coherence through quantum channels where successive uses of the channels are…

Quantum Physics · Physics 2016-12-30 You-neng Guo , Ke Zeng , Qing-long Tian , Zheng-da Li

Quantum superdense coding protocols enhance channel capacity by using shared quantum entanglement between two users. The channel capacity can be as high as 2 when one uses entangled qubits. However, this limit can be surpassed by using…

Quantum Physics · Physics 2019-05-09 Xiao-Min Hu , Yu Guo , Bi-Heng Liu , Yun-Feng Huang , Chuan-Feng Li , Guang-Can Guo

We review in a unified way a recently proposed method to detect properties of unknown quantum channels and lower bounds to quantum capacities, without resorting to full quantum process tomography. The method is based on the preparation of a…

Quantum Physics · Physics 2017-12-19 Chiara Macchiavello , Massimiliano F. Sacchi