ENTANGLEMENT DISTRIBUTION AND STATE DISCRIMINATION IN TRIPARTITE QUBIT SYSTEMS

2008 ◽  
Vol 06 (02) ◽  
pp. 237-253 ◽  
Author(s):  
J. BATLE ◽  
M. CASAS
Keyword(s):  
Monte Carlo ◽  
Entangled States ◽  
Perfect State ◽  
Mixed States ◽  
W States ◽  
State Discrimination ◽  
Entanglement Measures ◽  
Entanglement Distribution ◽  
Maximally Entangled States ◽  
Qubit States

This work reviews and extends recent results concerning the distribution of entanglement, as well as nonlocality (in terms of inequality violations) in tripartite qubit systems. With recourse to a Monte Carlo generation of pure and mixed states of three-qubits, we explore several features related to the distribution of entanglement (expressed in the form of different measures of multiqubit entanglement based upon bipartitions). Also, special interest is paid to maximally entangled states (such as the GHZ for three-qubits) and W states. This study also sheds some light on the interesting relation existing between some entanglement measures and perfect state discrimination in LOCC measurements relevant to cryptographic protocols. We round off the results by studying the distribution of entanglement between Alice and Bob in a modified teleportation protocol toy model over three-qubit states.

Multipartite entanglement and hyperdeterminants

2002 ◽  
Vol 2 (Special) ◽  
pp. 540-555
Author(s):  
A. Miyake ◽  
M. Wadati
Keyword(s):  
Entangled States ◽  
Multipartite Entanglement ◽  
Maximal Dimension ◽  
Ordered Structure ◽  
Mixed States ◽  
Separable States ◽  
Entanglement Measures ◽  
Pure States ◽  
Maximally Entangled States ◽  
Bipartite Case

We classify multipartite entanglement in a unified manner, focusing on a duality between the set of separable states and that of entangled states. Hyperdeterminants, derived from the duality, are natural generalizations of entanglement measures, the concurrence, 3-tangle for 2, 3 qubits respectively. Our approach reveals how inequivalent multipartite entangled classes of pure states constitute a partially ordered structure under local actions, significantly different from a totally ordered one in the bipartite case. Moreover, the generic entangled class of the maximal dimension, given by the nonzero hyperdeterminant, does not include the maximally entangled states in Bell's inequalities in general (e.g., in the \(n \!\geq\! 4\) qubits), contrary to the widely known bipartite or 3-qubit cases. It suggests that not only are they never locally interconvertible with the majority of multipartite entangled states, but they would have no grounds for the canonical \(n\)-partite entangled states. Our classification is also useful for that of mixed states.

Entanglement criteria for the three-qubit states

2017 ◽  
Vol 15 (07) ◽  
pp. 1750049 ◽  
Author(s):  
Y. Akbari-Kourbolagh
Keyword(s):  
White Noise ◽  
Tensor Products ◽  
W State ◽  
Entangled States ◽  
Mean Values ◽  
W States ◽  
Pauli Matrices ◽  
The Mean ◽  
Simple Sets ◽  
Qubit States

We present sufficient criteria for the entanglement of three-qubit states. For some special families of states, the criteria are also necessary for the entanglement. They are formulated as simple sets of inequalities for the mean values of certain observables defined as tensor products of Pauli matrices. The criteria are good indicators of the entanglement in the vicinity of three-qubit GHZ and W states and enjoy the capability of detecting the entangled states with positive partial transpositions. Furthermore, they improve the best known result for the case of W state mixed with the white noise. The efficiency of the criteria is illustrated through several examples.

scholarly journals Generalized Weyl-Heisenberg Algebra, Qudit Systems and Entanglement Measure of Symmetric States via Spin Coherent States. Part II: The Perma-Concurrence Parameter

Symmetry ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 875
Author(s):  
Mohammed Daoud ◽  
Maurice R. Kibler
Keyword(s):  
Heisenberg Algebra ◽  
Entangled States ◽  
Entanglement Measure ◽  
Bloch Sphere ◽  
Maximally Entangled States ◽  
Qubit States ◽  
Range Of Variation ◽  
Symmetric States ◽  
Unit Vectors ◽  
Spin Coherent States

This paper deals with separable and entangled qudits | ψ d ⟩ (quantum states in dimension d) constructed from Dicke states made of N = d - 1 qubits. Such qudits present the property to be totally symmetric under the interchange of the N qubits. We discuss the notion of perma-concurrence P d for the qudit | ψ d ⟩ , introduced by the authors (Entropy 2018, 20, 292), as a parameter for characterizing the entanglement degree of | ψ d ⟩ . For d = 3 , the perma-concurrence P 3 constitutes an alternative to the concurrence C for symmetric two-qubit states. We give several expressions of P d (in terms of matrix permanent and in terms of unit vectors of R 3 pointing on the Bloch sphere) and precise the range of variation of P d (going from separable to maximally entangled states). Numerous examples are presented for P d . Special attention is devoted to states of W type and to maximally entangled states of Bell and Greenberger–Horne–Zeilinger type.

Mixed maximally entangled states

2012 ◽  
Vol 12 (1&2) ◽  
pp. 63-73
Author(s):  
Z. G. Li ◽  
M. G. Zhao ◽  
S. M. Fei ◽  
H. Fan ◽  
W. M. Liu
Keyword(s):  
Entangled States ◽  
Classical Communication ◽  
Entanglement Of Formation ◽  
Entanglement Measures ◽  
Maximally Entangled States

We find that the mixed maximally entangled states exist and prove that the form of the mixed maximally entangled states is unique in terms of the entanglement of formation. Moreover, even if the entanglement is quantified by other entanglement measures, this conclusion is still proven right. This result is a supplementary to the generally accepted fact that all maximally entangled states are pure. These states possess important properties of the pure maximally entangled states, for example, these states can be used as a resource for faithful teleportation and they can be distinguished perfectly by local operations and classical communication.

DYNAMICS OF A COUPLED CAVITY SYSTEM COMPOSED OF THREE CAVITIES

2012 ◽  
Vol 10 (06) ◽  
pp. 1250070 ◽  
Author(s):  
ZHI-RONG ZHONG ◽  
XIU LIN ◽  
BIN ZHANG ◽  
ZHEN-BIAO YANG
Keyword(s):  
Theoretical Basis ◽  
Quantum States ◽  
Entangled States ◽  
W States ◽  
Atomic Excitation ◽  
Level Atom ◽  
Cavity System ◽  
Maximally Entangled States ◽  
The One ◽  
Coupled Cavity

We study the one-excitation dynamics of a coupled cavity system composed of three cavities, each containing a two-level atom. By adjusting the atom–cavity detuning Δ, cavity–cavity hopping rate v and the initial atomic excitation residential, a wide variety of time-evolution behaviors can be realized. Under certain conditions, the two-atom maximally entangled states and three-atom W states can be obtained. The results provide a theoretical basis for the manipulation of quantum states in such a system and will contribute to the understanding of more complex systems.

Bipartite entanglement of decohered mixed states generated from maximally entangled cluster states

2021 ◽  
Vol 36 (03) ◽  
pp. 2150010
Author(s):  
Mostafa Mansour ◽  
Saeed Haddadi
Keyword(s):  
Mixed State ◽  
Entangled States ◽  
Entangled State ◽  
Mixed States ◽  
Density Matrices ◽  
Bipartite Entanglement ◽  
Cluster States ◽  
Maximally Entangled State ◽  
Qubit System ◽  
Maximally Entangled States

In this work, we investigate the bipartite entanglement of decohered mixed states generated from maximally entangled cluster states of [Formula: see text] qubits physical system. We introduce the disconnected cluster states for an ensemble of [Formula: see text] non-interacting qubits and we give the corresponding separable density matrices. The maximally entangled states can be generated from disconnected cluster states, by assuming that the dynamics of the multi-qubit system is governed by a quadratic Hamiltonian of Ising type. When exposed to a local noisy interaction with the environment, the multi-qubit system evolves from its initial pure maximally entangled state to a decohered mixed state. The decohered mixed states generated from bipartite, tripartite and multipartite maximally entangled cluster states are explicitly expressed and their bipartite entanglements are investigated.

Remote preparation of four-qubit states via two-qubit maximally entangled states

2019 ◽  
Vol 18 (4) ◽  
Author(s):  
Yang Xue ◽  
Lei Shi ◽  
Xinyu Da ◽  
Kaihang Zhou ◽  
Lihua Ma ◽  
...  
Keyword(s):  
Entangled States ◽  
Remote Preparation ◽  
Maximally Entangled States ◽  
Qubit States

scholarly journals Quantum Contextual Advantage Depending on Nonzero Prior Probabilities in State Discrimination of Mixed Qubit States

Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1583
Author(s):  
Jaehee Shin ◽  
Donghoon Ha ◽  
Younghun Kwon
Keyword(s):  
Prior Probability ◽  
The State ◽  
Mixed States ◽  
Minimum Error ◽  
Prior Probabilities ◽  
Quantum Properties ◽  
State Discrimination ◽  
The Given ◽  
Qubit States ◽  
Selection Of

Recently, Schmid and Spekkens studied the quantum contextuality in terms of state discrimination. By dealing with the minimum error discrimination of two quantum states with identical prior probabilities, they reported that quantum contextual advantage exists. Meanwhile, if one notes a striking observation that the selection of prior probability can affect the quantum properties of the system, it is necessary to verify whether the quantum contextual advantage depends on the prior probabilities of the given states. In this paper, we consider the minimum error discrimination of two states with arbitrary prior probabilities, in which both states are pure or mixed. We show that the quantum contextual advantage in state discrimination may depend on the prior probabilities of the given states. In particular, even though the quantum contextual advantage always exists in the state discrimination of two nonorthogonal pure states with nonzero prior probabilities, the quantum contextual advantage depends on prior probabilities in the state discrimination of two mixed states.

scholarly journals Unified Monogamy Relations of Multipartite Entanglement

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Awais Khan ◽  
Junaid ur Rehman ◽  
Kehao Wang ◽  
Hyundong Shin
Keyword(s):  
Analytic Formula ◽  
Entangled States ◽  
Multipartite Entanglement ◽  
Entanglement Measure ◽  
Mixed States ◽  
Bipartite Entanglement ◽  
Entanglement Of Formation ◽  
Special Cases ◽  
Qubit States ◽  
Monogamy Relations

Abstract Unified-(q, s) entanglement $$({{\mathscr{U}}}_{q,s})$$ ( U q , s ) is a generalized bipartite entanglement measure, which encompasses Tsallis-q entanglement, Rényi-q entanglement, and entanglement of formation as its special cases. We first provide the extended (q; s) region of the generalized analytic formula of  $${{\mathscr{U}}}_{q,s}$$ U q , s . Then, the monogamy relation based on the squared  $${{\mathscr{U}}}_{q,s}$$ U q , s for arbitrary multiqubit mixed states is proved. The monogamy relation proved in this paper enables us to construct an entanglement indicator that can be utilized to identify all genuine multiqubit entangled states even the cases where three tangle of concurrence loses its efficiency. It is shown that this monogamy relation also holds true for the generalized W-class state. The αth power $${{\mathscr{U}}}_{q,s}$$ U q , s based general monogamy and polygamy inequalities are established for tripartite qubit states.

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