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Related papers: Nonlinear channels of Werner states

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Werner states are multipartite quantum states that are invariant under the diagonal conjugate action of the unitary group. This paper gives a complete characterization of their entanglement that is independent of the underlying local…

Quantum Physics · Physics 2022-11-22 Felix Huber , Igor Klep , Victor Magron , Jurij Volčič

We demonstrate how an effective density of states can be derived from the S-matrix describing a coupled-channel system. Besides the locations of poles, the phase of the determinant of the S-matrix encodes essential details in characterizing…

High Energy Physics - Phenomenology · Physics 2020-09-09 Pok Man Lo

Entanglement and Bell nonlocality are used to describe quantum inseparabilities. Bell-nonlocal states form a strict subset of entangled states. A natural question arises concerning how much territory Bell nonlocality occupies entanglement…

Quantum Physics · Physics 2019-09-04 Xiao-Gang Fan , Zhi-Yong Ding , Fei Ming , Huan Yang , Dong Wang , Liu Ye

We investigate the separability properties of quantum states described by an extended Werner density matrix, where the classical component exhibits statistical dependence. By generalizing the classical part to allow correlations, we…

General Physics · Physics 2025-07-22 Toru Ohira

In this paper, we write down the separable Werner state in a two-qubit system explicitly as a convex combination of product states, which is different from the convex combination obtained by Wootters' method. The Werner state in a two-qubit…

Quantum Physics · Physics 2007-05-23 Hiroo Azuma , Masashi Ban

The density matrix of a non-relativistic quantum system, divided into $N$ sub-systems, is rewritten in terms of the set of all partitioned density matrices for the system. For the case where the different sub-systems are distinguishable, we…

Quantum Physics · Physics 2018-12-19 Timothy Cox , Philip C. E. Stamp

The dynamics of entanglement between two-level atoms immersed in a common photon reservoir at finite temperature is investigated. It is shown that in the regime of strong correlations there are nontrivial asymptotic states which can be…

Quantum Physics · Physics 2015-05-14 Lech Jakobczyk

Transfer of entanglement and information is studied for quantum teleportation of an unknown entangled state through noisy quantum channels. We find that the quantum entanglement of the unknown state can be lost during the teleportation even…

Quantum Physics · Physics 2009-01-23 Jinhyoung Lee , M. S. Kim

The incompressible Quantum Hall strip is sensitive to charging of localized states in the cyclotron gap. We study the effect of localized states by a density functional approach and find electron density and the strip width as a function of…

Mesoscale and Nanoscale Physics · Physics 2008-04-12 Ivan A. Larkin , L. S. Levitov

We propose a theoretical scheme of quantum nondemolition measurement of two-qubit Werner state. We discuss our scheme with the two qubits restricted in a local place and then extend the scheme to the case in which two qubits are separated.…

Quantum Physics · Physics 2011-10-28 Jia-sen Jin , Chang-shui Yu , Pei Pei , He-shan Song

In this manuscript, the behavior of the Wigner function of accelerated and non-accelerated two qubit system passing through different noisy channels is discussed. The decoherence of the initial quantum correlation due to the noisy channels…

Quantum Physics · Physics 2019-03-25 M. Y. Abd-Rabbou , N. Metwally , M. M. A. Ahmed , A. -S. F. Obada

An extension to computational mechanics complexity measure is proposed in order to tackle quantum states complexity quantification. The method is applicable to any $n-$partite state of qudits through some simple modifications. A Werner…

Computational Physics · Physics 2011-10-28 Yuri Campbell , José Roberto Castilho Piqueira

We analyze the Pauli-channel estimation with mixed nonseparable states. It turns out that within a specific range entanglement can serve as a nonclassical resource. However, this range is rather small, that is entanglement is not very…

Quantum Physics · Physics 2009-11-07 Thorsten C. Bschorr , Dietmar G. Fischer , Matthias Freyberger

We consider Bell tests in which the distant observers can perform local filtering before testing a Bell inequality. Notably, in this setup, certain entangled states admitting a local hidden variable model in the standard Bell scenario can…

Quantum Physics · Physics 2016-12-01 Flavien Hirsch , Marco Túlio Quintino , Joseph Bowles , Tamás Vértesi , Nicolas Brunner

An addition rule of impure density operators, which provides a pure state density operator, is formulated. Quantum interference including visibility property is discussed in the context of the density operator formalism. A measure of…

Quantum Physics · Physics 2009-11-07 Vladimir I Man'ko , Giuseppe Marmo , E C George Sudarshan , Francesco Zaccaria

We consider a system of static spin qubits embedded in a one-dimensional spin coherent channel and develop a scheme to readout the state of one and two qubits separately. We use unpolarized flying qubits for this purpose that scatter off…

Quantum Physics · Physics 2021-06-02 Amritesh Sharma , Ashwin A. Tulapurkar

We perform numerical tests on quantum nonlocality of two-level quantum systems (qubits) observed by a uniformly moving observer. Under a suitable momentum setting, the quantum nonlocality of two-qubit nonmaximally entangled states could be…

Quantum Physics · Physics 2015-06-15 Hong-Yi Su , Yu-Chun Wu , Jing-Ling Chen , Chunfeng Wu , L. C. Kwek

We present a method to detect properties of quantum channels, assuming that some a priori information about the form of the channel is available. The method is based on a correspondence with entanglement detection methods for multipartite…

Quantum Physics · Physics 2013-11-13 C. Macchiavello , M. Rossi

Quantum entanglement, one of the defining features of quantum mechanics, has been demonstrated in a variety of nonlinear spin-like systems. Quantum entanglement in linear systems has proven significantly more challenging, as the intrinsic…

To quantify the effect of decoherence in quantum measurements, it is desirable to measure not merely the square modulus of the spatial wavefunction, but the entire density matrix, whose phases carry information about momentum and how pure…

Quantum Physics · Physics 2009-10-30 Max Tegmark