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Quantum entanglement assisted with measurements provides various pathways to communicate information to parties within a network. In this work, we generalize a previous broadcasting protocol and present schemes to broadcast product and…

We study the quantumness of bipartite correlations by proposing a quantity that combines a measure of total correlations -- mutual information -- with the notion of broadcast copies -- i.e., generally nonfactorized copies -- of bipartite…

Quantum Physics · Physics 2009-07-17 M. Piani , M. Christandl , C. E. Mora , P. Horodecki

In hybrid quantum systems a controllable coupling can be obtained by mediating the interactions with dynamically introduced photons. We propose a hybrid quantum architecture consisting of two nitrogen vacancy center ensembles coupled to a…

Quantum Physics · Physics 2019-11-05 Kayleigh Mathieson , Somnath Bhattacharyya

Bosonic channels describe quantum-mechanically many practical communication links such as optical, microwave, and radiofrequency. We investigate the maximum rates for the bosonic multiple access channel (MAC) in the presence of thermal…

Quantum Physics · Physics 2022-07-19 Evan J. D. Anderson , Boulat A. Bash

We have previously shown that quantum-enhanced atom interferometry can be achieved by mapping the quantum state of squeezed optical vacuum to one of the atomic inputs via a beamsplitter-like process [Phys.~Rev.~A \textbf{90}, 063630…

Quantum Physics · Physics 2015-04-01 Behnam Tonekaboni , Simon A. Haine , Stuart S. Szigeti

Coupled quantum harmonic oscillators, studied by many authors using many different techniques over the decades, are frequently used toy-models to study open quantum systems. In this manuscript, we explicitly study the simplest oscillator…

Quantum Physics · Physics 2014-02-06 Yingkai Ouyang , Wee Hao Ng

This paper investigates a practical partially-connected hybrid beamforming transmitter for integrated sensing and communication (ISAC) with distortion from nonlinear power amplification. For this ISAC system, we formulate a communication…

Signal Processing · Electrical Eng. & Systems 2025-07-21 Zeyuan Zhang , Yue Xiu , Phee Lep Yeoh , Guangyi Liu , Zixing Wu , Ning Wei

We demonstrate that the quantum communication between two parties can be significantly improved if the receiver is allowed to store the received signals in a quantum memory before decoding them. In the limit of an infinite memory, the…

Quantum Physics · Physics 2007-05-23 Vittorio Giovannetti , Daniel Burgarth

Optical communication systems are able to send the information from one user to another in light beams that travel through the free space or optical fibers, therefore how to send larger amounts of information in smaller periods of time is a…

Quantum Physics · Physics 2018-03-07 Wen-Tan Fang , Yin-Hai Li , Zhi-Yuan Zhou , Li-Xin Xu , Guang-Can Guo , Bao-Sen Shi

The density operator for a quantum system in thermal equilibrium with its environment depends on Planck's constant, as well as the temperature. At high temperatures, the Weyl representation, that is, the thermal Wigner function, becomes…

Quantum Physics · Physics 2021-06-30 Alfredo M. Ozorio de Almeida , Gert-Ludwig Ingold , Olivier Brodier

Hybrid quantum systems have been developed with various mechanical, optical and microwave harmonic oscillators. The coupling produces a rich library of interactions including two mode squeezing, swapping interactions, back-action evasion…

In this brief report we present a feasible scheme to split quantum information in the realm of traveling waves. An oversimplified scheme is also proposed for the generation of a class of W states useful for perfect teleportation and…

Quantum Physics · Physics 2009-09-03 W. B. Cardoso , N. G. de Almeida , A. T. Avelar , B. Baseia

Oscillating neutrino beams exhibit quantum coherence over distances of thousands of kilometers. Their unambiguously quantum nature suggests an appealing test system for direct quantum simulation. Such techniques may enable presently…

Quantum Physics · Physics 2022-04-13 M. J. Molewski , B. J. P. Jones

Information transmission of two qubits through two independent 1D Heisenberg chains as a quantum channel is analyzed. It is found that the entanglement of two spin-$\frac 12$ quantum systems is decreased during teleportation via the thermal…

Quantum Physics · Physics 2009-11-11 X. Hao , S. Zhu

We discuss and generalize multi-particle entanglement based on statistical correlations using Ursell-Mayer type of cluster coefficients. Cluster coefficients are used to distinguish different, independent entangled systems as well as those…

Quantum Physics · Physics 2009-11-15 Atul Kumar , Mangala Sunder Krishnan

We address the problem of the optimal quantum estimation of the coupling parameter of a bilinear interaction, such as the transmittivity of a beam splitter or the internal phase-shift of an interferometer. The optimal measurement scheme…

Quantum Physics · Physics 2007-05-23 G. Mauro D'Ariano , Matteo G. A. Paris , Paolo Perinotti

Quantum harmonic oscillators are central to many modern quantum technologies. We introduce a method to determine the frequency noise spectrum of oscillator modes through coupling them to a qubit with continuously driven…

Quantum states can be efficiently transferred over a long distance if the entire quantum channel can be divided into several small blocks. We consider a scenario in which each block consists of two copies of a multiparty state -- one is…

Quantum Physics · Physics 2020-10-29 Saptarshi Roy , Tamoghna Das , Debmalya Das , Aditi Sen De , Ujjwal Sen

Superradiance, the enhanced collective emission of light from a coherent ensemble of quantum systems, has been typically studied in atomic ensembles. In this work we study the enhanced emission of energy from coherent ensembles of harmonic…

Quantum Physics · Physics 2011-07-27 Michael Delanty , Stojan Rebic , Jason Twamley

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