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Related papers: A computable measure of nonclassicality for light

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Through concurrence, we characterize the entanglement properties of optical coherent-state qubits subject to an amplitude damping channel. We investigate the distillation capabilities of known error correcting codes and obtain upper bounds…

Quantum Physics · Physics 2011-02-10 Ricardo Wickert , Nadja Kolb Bernardes , Peter van Loock

Multipartite entanglement and nonclassicality of four-mode Gaussian states generated in two simultaneous nonlinear processes involving parametric down-conversion and frequency up-conversion are analyzed assuming the vacuum as the initial…

Quantum Physics · Physics 2016-09-26 Ievgen I. Arkhipov , Jan Peřina , Ondřej Haderka , Alessia Allevi , Maria Bondani

Entanglement is a fundamental feature of quantum mechanics and holds great promise for enhancing metrology and communications. Much of the focus of quantum metrology so far has been on generating highly entangled quantum states that offer…

According to Born's rule quantum probabilities are given by the overlap between the system state and measurement states in a quite symmetrical way. This means that both contribute to any observed nonclassical effect that is usually…

Quantum Physics · Physics 2019-05-21 Alfredo Luis , Laura Ares

Nonclassicality, defined in the quantum optical sense, serves as a resource for photon-based quantum technologies. Therefore, certifying the nonclassicality of a quantum state is crucial for gauging its potential for quantum advantage.…

Gradual loss of the entanglement of a twin beam containing around 25 photon pairs with the increasing external noise is experimentally investigated. The entanglement is quantified by the non-classicality depths and the non-classicality…

Quantum Physics · Physics 2020-08-12 Vaclav Michalek , Jan Perina , Ondrej Haderka

Entanglement and coherence are fundamental properties of quantum systems, promising to power near future quantum technologies, such as quantum computation, quantum communication and quantum metrology. Yet, their quantification, rather than…

Entropic entanglement measures of a two-dimensional system of two Coulombically interacting particles confined in an anisotropic harmonic potential are discussed in dependence on the anisotropy and the interaction strength. The harmonic…

Quantum Physics · Physics 2017-07-18 Przemyslaw Koscik , Anna Okopinska

We introduce two independent quantifications for 3-mode and 4-mode entanglement. We investigate the conversion of one type of nonclassicality, i.e. single-mode nonclassicality, into another type of nonclassicality, i.e. multi-mode…

Quantum Physics · Physics 2020-01-22 Mehmet Emre Tasgin , M. Suhail Zubairy

In quantum optics, measurement statistics -- for example, photocounting statistics -- are considered nonclassical if they cannot be reproduced with statistical mixtures of classical radiation fields. We have formulated a necessary and…

Quantum Physics · Physics 2024-09-02 V. S. Kovtoniuk , E. V. Stolyarov , O. V. Kliushnichenko , A. A. Semenov

We present an entanglement criterion for two mode squeezed states which relies on particle counting only. The proposed inequality is optimal for the state under consideration and robust against particle losses up to 2/3. As it does not…

Quantum Physics · Physics 2008-09-16 Christine A. Muschik , Eugene S. Polzik , J. Ignacio Cirac

Entanglement, and quantum correlation, are precious resources for quantum technologies implementation based on quantum information science, such as, for instance, quantum communication, quantum computing, and quantum interferometry.…

Quantum Physics · Physics 2023-05-22 Arthur Vesperini , Ghofrane Bel-Hadj-Aissa , Roberto Franzosi

Numerous inequalities involving moments of integrated intensities and revealing nonclassicality and entanglement in bipartite optical fields are derived using the majorization theory, non-negative polynomials, the matrix approach, as well…

Quantum Physics · Physics 2018-12-11 Jan Perina , Ievgen I. Arkhipov , Vaclav Michalek , Ondrej Haderka

Exceptional points (EPs) are degeneracies in open wave systems with coalescence of at least two energy levels and their corresponding eigenstates. In higher dimensions, more complex EP physics not found in two-state systems is observed. We…

Quantum entanglement is an essential ingredient for the absolute security of quantum communication. Generation of continuous-variable entanglement or two-mode squeezing between light fields based on the effect of electromagnetically induced…

Quantum Physics · Physics 2019-07-01 You-Lin Chuang , Ray-Kuang Lee , Ite A. Yu

Indeterminacy associated with probing of a quantum state is commonly expressed through spectral distances (metric) featured in the outcomes of repeated experiments. Here we express it as an effective amount (measure) of distinct outcomes…

Quantum Physics · Physics 2021-09-21 Ivan Horváth

In quantum optics a pure state is considered classical, relative to the statistics of photodetection, if and only if it is a coherent state. A different and newer notion of nonclassicality is based on modal entanglement. One example that…

Quantum Physics · Physics 2013-10-08 Zhang Jiang , Matthias D. Lang , Carlton M. Caves

This paper aims to stress the role of the Cahill-Glauber quasi-probability densities in defining, detecting, and quantifying the non-classicality of field states in quantum optics. The distance between a given pure state and the set of all…

Quantum Physics · Physics 2020-04-22 Paulina Marian , Tudor A. Marian

This book chapter reports on theoretical protocols for generating nonclassical states of light and mechanics. Nonclassical states are understood as squeezed states, entangled states or states with negative Wigner function, and the…

We propose a review of recent developments on entanglement and non-classical effects in collective two-atom systems and present a uniform physical picture of the many predicted phenomena. The collective effects have brought into sharp focus…

Quantum Physics · Physics 2009-11-10 Z. Ficek , R. Tanas
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