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Related papers: Continuous variable graph states: entanglement and…

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We investigate the connection between entanglement and non-locality between continuous-variable bipartite Gaussian states. The investigation initiates with formulating non-locality by using the phase-space Wigner representation of Bell's…

Quantum Physics · Physics 2025-07-31 Souvik Agasti

We introduce a class of mixed multiqubit states, that corresponds to a randomized version of graph states. Such states arise when a graph state is prepared with noisy or imperfect controlled-Z gates. We study the entanglement features of…

We investigate the entanglement of the ground state in the quantum networks that their nodes are considered as quantum harmonic oscillators. To this aim, the Schmidt numbers and entanglement entropy between two arbitrary partitions of a…

Quantum Physics · Physics 2016-11-25 M. A. Jafarizadeh , S. Nami , F. Eghbalifam

The geometric measure of entanglement of a pure quantum state is defined to be its distance to the space of product (seperable) states. Given an $n$-partite system composed of subsystems of dimensions $d_1,\ldots, d_n$, an upper bound for…

Quantum Physics · Physics 2018-05-09 Liqun Qi , Guofeng Zhang , Guyan Ni

Graph states play an important role in quantum information theory through their connection to measurement-based computing and error correction. Prior work has revealed elegant connections between the graph structure of these states and…

Quantum Physics · Physics 2025-04-15 Louis Schatzki , Linjian Ma , Edgar Solomonik , Eric Chitambar

We study the entanglement entropy of harmonic oscillators in noncommutative phase space. We propose a new definition of quantum R\'enyi entropy based on Wigner functions in noncommutative phase space. Using the R\'enyi entropy, we calculate…

Mathematical Physics · Physics 2019-08-12 Bing-Sheng Lin , Jian Xu , Tai-Hua Heng

An asymptotic entanglement measure for any bipartite states is derived in the light of the dense coding capacity optimized with respect to local quantum operations and classical communications. General properties and some examples with…

Quantum Physics · Physics 2015-06-26 Tohya Hiroshima

We analyze the quantum entanglement properties of bosonic particles hopping over graph structures.Mode-entanglement of a graph vertex with respect the rest of the graph is generated, starting from a product state, by turning on for a finite…

Quantum Physics · Physics 2009-11-10 Paolo Giorda , Paolo Zanardi

We study the detection of continuous-variable entanglement, for which most of the existing methods designed so far require a full specification of the devices, and we present protocols for entanglement detection in a scenario where the…

Quantum Physics · Physics 2021-05-19 Paolo Abiuso , Stefan Bäuml , Daniel Cavalcanti , Antonio Acín

The bi-partite Gaussian state, corresponding to an anisotropic harmonic oscillator in a noncommutative-space, is investigated with the help of the Simon's separability condition (generalized Peres-Horodecki criterion). It turns out that, in…

Quantum Physics · Physics 2022-12-16 Pinaki Patra

In this paper, we study the multipartite entanglement properties of graph states up to seven qubits. Our analysis shows that the generalized concurrence measure is more efficient than geometric entanglement measure for measuring…

Quantum Physics · Physics 2023-07-20 Saeed Haddadi , Ahmad Akhound , Mohammad Ali Chaman Motlagh

We introduce a homology-based technique for the analysis of multiqubit state vectors. In our approach, we associate state vectors to data sets by introducing a metric-like measure in terms of bipartite entanglement, and investigate the…

Quantum Physics · Physics 2020-03-25 Riccardo Mengoni , Alessandra DI Pierro , Laleh Memarzadeh , Stefano Mancini

Entanglement is known to serve as an order parameter for true topological order in two-dimensional systems. We show how entanglement of disconnected partitions defines topological invariants for one-dimensional topological superconductors.…

We study the ground-state entanglement of one-dimensional harmonic chains that are coupled to each other by a collective interaction as realized e.g. in an anisotropic ion crystal. Due to the collective type of coupling, where each chain…

Quantum Physics · Physics 2013-05-29 R. G. Unanyan , M. Fleischhauer , D. Bruss

We review the theory of continuous-variable entanglement with special emphasis on foundational aspects, conceptual structures, and mathematical methods. Much attention is devoted to the discussion of separability criteria and entanglement…

Quantum Physics · Physics 2009-07-02 Gerardo Adesso , Fabrizio Illuminati

This article delves into an analysis of the intrinsic entanglement and separability feature in quantum states as depicted by graph Laplacian. We show that the presence or absence of edges in the graph plays a pivotal role in defining the…

Quantum Physics · Physics 2024-01-05 Anoopa Joshi , Parvinder Singh , Atul Kumar

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of the dynamics of entanglement for a system consisting of two uncoupled harmonic oscillators interacting with a…

Quantum Physics · Physics 2015-05-27 Aurelian Isar

Complex networks structures have been extensively used for describing complex natural and technological systems, like the Internet or social networks. More recently complex network theory has been applied to quantum systems, where complex…

Quantum Physics · Physics 2020-01-22 Francesca Sansavini , Valentina Parigi

We present a criterion for multiparticle entanglement based on covariance matrices. On the one hand, the criterion allows to detect bound entangled states which are not detected by other criteria; on the other hand, some strongly entangled…

Quantum Physics · Physics 2010-09-13 Oleg Gittsovich , Philipp Hyllus , Otfried Gühne

We explore the possibility of entanglement detection in continuous variable systems by entanglement witnesses based on covariance matrices, constructible from random homodyne measurements. We propose new linear constraints characterizing…

Quantum Physics · Physics 2021-01-20 Tatiana Mihaescu , Hermann Kampermann , Giulio Gianfelici , Aurelian Isar , Dagmar Bruss