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The hybrid entangled states generated, e.g., in a trapped-ion or atom-cavity system, have exactly one ebit of entanglement, but are not maximally entangled. We demonstrate this by showing that they violate, but in general do not maximally…

Quantum Physics · Physics 2009-11-07 Zeng-Bing Chen , Guang Hou , Yong-De Zhang

It is emphasized that quantum entanglement determined in terms of the von Neumann entropy operator is a stochastic quantity and, therefore, can fluctuate. The rms fluctuations of the entanglement entropy of two-qubit systems in both pure…

Quantum Physics · Physics 2015-05-14 E. B. Fel'dman , M. A. Yurishchev

Preserving multipartite entanglement amidst decoherence poses a pivotal challenge in quantum information processing. However, assessing multipartite entanglement in mixed states amid decoherence presenting a formidable task. Employing…

Quantum Physics · Physics 2026-03-16 Sovik Roy , Md. Manirul Ali , Abhijit Mandal , Chandrashekar Radhakrishnan

We study nonclassical correlations in propagating two-mode squeezed microwave states in the presence of noise. We focus on two different types of correlations, namely, quantum entanglement and quantum discord. Quantum discord has various…

We study the capacity of d-dimensional quantum channels with memory modeled by correlated noise. We show that, in agreement with previous results on Pauli qubit channels, there are situations where maximally entangled input states achieve…

Quantum Physics · Physics 2007-05-23 E. Karpov , D. Daems , N. J. Cerf

We show that quantum mechanical entanglement can prevail even in noisy open quantum systems at high temperature and far from thermodynamical equilibrium, despite the deteriorating effect of decoherence. The system consists of a number N of…

Quantum Physics · Physics 2007-05-23 L. Hartmann , W. Dür , H. -J. Briegel

We analyze the dynamics of entanglement in a two-qubit system interacting with an initially squeezed thermal environment via a quantum nondemolition system-reservoir interaction, with the system and reservoir assumed to be initially…

Quantum Physics · Physics 2015-05-13 Subhashish Banerjee , V. Ravishankar , R. Srikanth

Quantum entanglement and coherence are two fundamental resources for quantum information processing. Recent results clearly demonstrate their relevance in quantum technological tasks, including quantum communication and quantum algorithms.…

Quantum Physics · Physics 2018-04-16 Anurag Anshu , Rahul Jain , Alexander Streltsov

Starting from several copies of bipartite noisy entangled states, we design a global and optimal local measurement-based protocol in one- and two-dimensional lattices by which any two or more prefix sites can be connected via entanglement.…

Quantum Physics · Physics 2021-01-04 Ratul Banerjee , Srijon Ghosh , Shiladitya Mal , Aditi Sen De

We embarked upon the task of experimental protection of different classes of tripartite entangled states, namely the maximally entangled GHZ and W states and the ${\rm W \bar{W}}$ state, using dynamical decoupling. The states were created…

Quantum Physics · Physics 2018-02-07 Harpreet Singh , Arvind , Kavita Dorai

We consider explicitly two examples of d-dimensional quantum channels with correlated noise and show that, in agreement with previous results on Pauli qubit channels, there are situations where maximally entangled input states achieve…

Quantum Physics · Physics 2007-05-23 E. Karpov , D. Daems , N. J. Cerf

Entanglement is not only the most intriguing feature of quantum mechanics, but also a key resource in quantum information science. The entanglement content of random pure quantum states is almost maximal; such states find applications in…

Quantum Physics · Physics 2009-04-04 Giuliano Benenti

We demonstrate by an explicit model calculation that the decay of entanglement of two two-state systems (two qubits) is governed by the product of the factors that measure the degree of decoherence of each of the qubits, subject to…

Quantum Physics · Physics 2010-10-12 D. Tolkunov , V. Privman , P. K. Aravind

We study the nonlocal properties of states resulting from the mixture of an arbitrary entangled state rho of two d-dimensional systems and completely depolarized noise, with respective weights p and 1-p. We first construct a local model for…

Quantum Physics · Physics 2007-08-02 Mafalda L. Almeida , Stefano Pironio , Jonathan Barrett , Geza Toth , Antonio Acin

Any kind of quantum resource useful in different information processing tasks is vulnerable to several types of environmental noise. Here we study the behaviour of quantum correlations such as entanglement and steering in two-qubit systems…

Quantum Physics · Physics 2021-01-13 Suchetana Goswami , Sibasish Ghosh , A. S. Majumdar

Quantum entanglement is a crucial resource in quantum information processing, and protecting it against noise poses a significant challenge. This paper introduces two strategies for preserving qutrit-qutrit entanglement in the presence of…

Quantum Physics · Physics 2026-04-24 Xing Xiao , Wen-Rui Huang , Tian-Xiang Lu , Yan-Ling Li

Non-locality without entanglement is a rather counter-intuitive phenomenon in which information may be encoded entirely in product (unentangled) states of composite quantum systems in such a way that local measurement of the subsystems is…

Quantum Physics · Physics 2017-03-08 Sarah Croke , Stephen M Barnett

We find that a bipartite quantum state is entangled if and only if it is quantum coherent with respect to complete bases of states in the corresponding system that are distinguishable under local quantum operations and classical…

Quantum Physics · Physics 2022-01-19 Asmitha Mekala , Ujjwal Sen

We investigate quantum states that posses both maximum entanglement and maximum discord between the pertinent parties. Since entanglement (discord) is defined only for bipartite (two qubit) systems, we shall introduce an appropriate sum…

Quantum Physics · Physics 2013-03-27 J. Batle , M. Casas , A. Plastino

We investigate entanglement distribution in pure-state quantum networks. We consider the case when non-maximally entangled two-qubit pure states are shared by neighboring nodes of the network. For a given pair of nodes, we investigate how…

Quantum Physics · Physics 2009-01-19 S. Perseguers , J. Wehr , A. Acin , M. Lewenstein , J. I. Cirac