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Related papers: Atmospheric Channel Characteristics for Quantum Co…

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Single-mode or mode multiplexed free-space atmospheric optical channels draw increasingly more attention in the last decade. The scope of their possible applications spans from the compatibility with the telecom WDM technology, fiber…

Quantum Physics · Physics 2019-01-30 K. S. Kravtsov , A. K. Zhutov , I. V. Radchenko , S. P. Kulik

Timescale comparison between optical atomic clocks over ground-to-space and terrestrial free-space laser links will have enormous benefits for fundamental and applied science, from measurements of fundamental constants and searches for dark…

In these last years, many studies have focalized on the design of reliable underwater acoustic communication systems. However, the ocean acoustic communication channel exhibits strong amplitude and phase fluctuations and the phenomena of…

Signal Processing · Electrical Eng. & Systems 2019-07-16 Yasin Yousif Al-Aboosi , Hussein A. Abdulnabi

We present the detection and characterization of fluctuations in linearly polarized emission from the atmosphere above the South Pole. These measurements make use of data from the SPT-3G receiver on the South Pole Telescope in three…

Spatial light modulators are versatile devices employed in a vast range of applications to modify the transverse phase or amplitude profile of an incident light beam. Most experiments are designed to use a specific polarization which…

Quantum Physics · Physics 2014-05-06 G. Barreto Lemos , J. O. de Almeida , S. P. Walborn , P. H. Souto Ribeiro , M. Hor-Meyll

Free-space optical (FSO) communication can be subject to various types of distortion and loss as the signal propagates through non-uniform media. In experiment and simulation, we demonstrate that the state of polarization and degree of…

In this paper, the channel of an indoor holographic multiple-input multiple-output (MIMO) system is measured. It is demonstrated through experiments for the first time that the spatial oversampling of holographic MIMO systems is able to…

Information Theory · Computer Science 2023-01-16 Tengjiao Wang , Yongxi Liu , Ming Zhang , Wei E. I. Sha , Cen Ling , Chao Li , Shaobo Wang

We provide a rigorous treatment of the entanglement properties of two-mode Gaussian states in atmospheric channels by deriving and analyzing the input-output relations for the corresponding entanglement test. A key feature of such turbulent…

Quantum Physics · Physics 2016-07-27 M. Bohmann , A. A. Semenov , J. Sperling , W. Vogel

We present a full experimental characterization of continuous variable quantum communication channels established by shared entanglement together with local operations and classical communication. The resulting teleportation channel was…

Quantum Physics · Physics 2009-11-13 James DiGuglielmo , Boris Hage , Alexander Franzen , Jaromir Fiurasek , Roman Schnabel

Vector beams are inhomogeneously polarized optical fields with nonseparable, quantum-like correlations between their polarisation and spatial components, and hold tremendous promise for classical and quantum communication across various…

A simple model describing depolarization channels with zero-bandwidth environment is presented and exactly solved. The environment is modelled by Lorentzian, telegraphic and Gaussian zero-bandwidth noises. Such channels can go beyond the…

Quantum Physics · Physics 2016-08-16 Andrzej Dragan , Krzysztow Wódkiewicz

Multiple-degrees-of-freedom free-space communication combining polarization and high-order spatial modes promises high-capacity communication channel. While high-order spatial modes have been widely exploited for dense coding and…

Quantum Physics · Physics 2016-03-17 Ling Ji , Ai-Lin Yang , Xiao-Feng Lin , Xian-Min Jin

Quantum networks, which integrate multiple quantum computers and the channels connecting them, are crucial for distributed quantum information processing but remain inherently susceptible to channel noise. Channel purification emerges as a…

Quantum teleportation of a continuous-variable state is studied for the quantum channel of a two-mode squeezed vacuum influenced by a thermal environment. Each mode of the squeezed vacuum is assumed to undergo the same thermal influence. It…

Quantum Physics · Physics 2009-11-06 Jinhyoung Lee , M. S. Kim , Hyunseok Jeong

The possibility of stochastic resonance of a quantum channel and hence the noise enhanced capacity of the channel is explored by considering the depolarizing channel. The fidelity of the channel is also considered. Although there is no…

Statistical Mechanics · Physics 2007-05-23 Julian Juhi-Lian Ting

Quantum Key Distribution (QKD) is a key exchange protocol which is implemented over free space optical links and optical fiber cable. When direct communication is not possible, QKD is performed over fiber cables, but the imperfections in…

Quantum Physics · Physics 2019-03-14 Vishal Sharma , Subhashish Banerjee

Free-space optical (FSO) links supporting spatial multiplexing provide a natural physical realization of Quantum MIMO channels. We develop a first-principles model for Quantum MIMO channels derived directly from wave-optical propagation…

Quantum Physics · Physics 2026-04-09 Heyang Peng , Seid Koudia , Semih Oktay , Mert Bayraktar , Symeon Chatzinotas

In the present paper we consider the problem of resonance line polarization formed in the spherically symmetric expanding atmospheres. For the solution of the concerned polarized transfer equation we use the comoving frame formulation, and…

Solar and Stellar Astrophysics · Physics 2020-01-20 A. Megha , M. Sampoorna , K. N. Nagendra , L. S. Anusha , K. Sankarasubramanian

Quantum channels describe the most general dynamics of open quantum systems. A quantum channel, as a linear map on vectorized quantum states, can be represented by a single matrix, whose spectrum is called the channel spectrum. Here we…

Quantum Physics · Physics 2026-01-28 Yuan-De Jin , Wen-Long Ma

We explore covert communication of qubits over the lossy thermal-noise bosonic channel, which is a quantum-mechanical model of many practical channels, including optical. Covert communication ensures that an adversary is unable to detect…