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Related papers: Quantum Gaussian Channels with Weak Measurements

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We present a simple model of quantum communication where a noisy quantum channel may benefit from the addition of further noise at the decoding stage. We demonstrate enhancement of the classical information capacity of an amplitude damping…

Quantum Physics · Physics 2015-06-26 Garry Bowen , Stefano Mancini

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

Gaussian channel simulation is an essential paradigm in understanding the evolution of bosonic quantum states. It allows us to investigate how such states are influenced by the environment and how they transmit quantum information. This…

We present upper bounds on the quantum and private capacity of single-mode, phase-insentitive Bosonic Gaussian Channels based on degradable extensions. Our findings are state-of-the-art in the following parameter regions: low temperature…

Quantum Physics · Physics 2021-12-01 Marco Fanizza , Farzad Kianvash , Vittorio Giovannetti

A protocol of quantum dense coding protection of two qubits is proposed in amplitude damping (AD) channel using weak measurement and reversal measurement. It is found that the capacity of quantum dense coding under the weak measurement and…

Quantum Physics · Physics 2018-03-16 Mao-Bin Tian , Guo-Feng Zhang

Dephasing is a prominent noise mechanism that afflicts quantum information carriers, and it is one of the main challenges towards realizing useful quantum computation, communication, and sensing. Here we consider discrimination and…

Quantum Physics · Physics 2024-06-11 Zixin Huang , Ludovico Lami , Mark M. Wilde

We describe the implementation of weak quantum measurements in superconducting qubits, focusing specifically on transmon type devices in the circuit quantum electrodynamics architecture. To access this regime, the readout cavity is probed…

Quantum Physics · Physics 2015-07-29 K. W. Murch , R. Vijay , I. Siddiqi

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

Weak values, obtained from weak measurements, attempt to describe the properties of a quantum system as it evolves from an initial to a final state, without practically altering this evolution. Trajectories can be defined from weak…

Quantum Physics · Physics 2015-07-09 Alex Matzkin

Noisy quantum channels may be used in many information carrying applications. We show that different applications may result in different channel capacities. Upper bounds on several of these capacities are proved. These bounds are based on…

Quantum Physics · Physics 2009-10-30 Howard Barnum , M. A. Nielsen , Benjamin Schumacher

When a noisy communication channel is used multiple times, the errors occurring at different times generally exhibit correlations. Classically, these correlations do not affect the evolution of individual particles: a single classical…

Quantum Physics · Physics 2021-12-07 Hlér Kristjánsson , Wenxu Mao , Giulio Chiribella

It is well known that, in general, feedback may enlarge the capacity region of Gaussian broadcast channels. This has been demonstrated even when the feedback is noisy (or partial-but-perfect) and only from one of the receivers. The only…

Information Theory · Computer Science 2015-02-18 Sibi Raj B. Pillai , Vinod M. Prabhakaran

The information-theoretic definition of quantum correlation, e.g., quantum discord, is measurement dependent. By considering the more general quantum measurements, weak measurements, which include the projective measurement as a limiting…

Quantum Physics · Physics 2015-04-13 Ming-Liang Hu , Heng Fan , Dong-Ping Tian

Weak values arise in quantum theory when the result of a weak measurement is conditioned on a subsequent strong measurement. The majority of the trials are discarded, leaving only very few successful events. Intriguingly those can display a…

Quantum Physics · Physics 2016-05-19 George C. Knee , Joshua Combes , Christopher Ferrie , Erik M. Gauger

We describe some applications of quantum information theory to the analysis of quantum limits on measurement sensitivity. A measurement of a weak force acting on a quantum system is a determination of a classical parameter appearing in the…

Quantum Physics · Physics 2012-03-28 Andrew M. Childs , John Preskill , Joseph Renes

Coherence is a basic notion for quantum states. Instead of quantum states, in this work, We establish a resource theory for quantifying the coherence of Gaussian channels. To do this, we propose the definitions of incoherent Gaussian…

Quantum Physics · Physics 2019-08-15 Jianwei Xu

We study classical capacity regions of quantum Gaussian multiple access channels (MAC). In classical variants of such channels, whilst some capacity superadditivity-type effects such as the so called {\it water filling effect} may be…

Quantum Physics · Physics 2013-05-29 L. Czekaj , J. K. Korbicz , R. W. Chhajlany , P. Horodecki

We investigate the capacity of three symmetric quantum states in three real dimensions to carry classical information. Several such capacities have already been defined, depending on what operations are allowed in the sending and receiving…

Quantum Physics · Physics 2007-05-23 Peter W. Shor

The ultimate limits of continuous-variable single-mode quantum teleportation due to absorption are studied, with special emphasis on (quasi-)monochromatic optical fields propagating through fibers. It is shown that even if an infinitely…

Quantum Physics · Physics 2009-11-07 A. V. Chizhov , L. Knöll , D. -G. Welsch

We discuss the problem of transfering a qubit from Alice to Bob using a noisy quantum channel and only finite resources. As the basic protocol for the transfer we apply quantum teleportation. It turns out that for a certain quality of the…

Quantum Physics · Physics 2009-11-06 Dietmar G. Fischer , Holger Mack , Matthias Freyberger