Geometrical analysis and entanglement measure of symmetric multiqubit states

2020 ◽  
Vol 17 (08) ◽  
pp. 2050119
Author(s):  
Bilal Benzimoun ◽  
Mohammed Daoud
Keyword(s):  
Coherent States ◽  
Entanglement Measure ◽  
Bloch Sphere ◽  
Geometrical Analysis ◽  
Majorana Representation ◽  
Multipartite States ◽  
Symmetric Multiqubit States ◽  
Spin Coherent States

We geometrically examine the entanglement in symmetric multiquibt states using the spin coherent states properties. We employ the Majorana representation to examine how coherent (polarized) and unpolarized states can be represented in the Bloch sphere and subsequently to quantify entanglement in multipartite systems. Entanglement can be viewed as a distance separate two points in Bloch sphere and how this notion can be extended for multipartite states in W class. This provides us with an entanglement measure for [Formula: see text]-states analogue to the notion of Concurrence.

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.

scholarly journals Majorana representation of symmetric multiqubit states

2011 ◽  
Vol 11 (3) ◽  
pp. 685-710 ◽  
Author(s):  
A. R. Usha Devi ◽  
Sudha ◽  
A. K. Rajagopal
Keyword(s):  
Majorana Representation ◽  
Symmetric Multiqubit States

Nonclassicality of photon-modulated spin coherent states in the Holstein-Primakoff realization

2021 ◽  
Author(s):  
Xiaoyan Zhang ◽  
Jisuo Wang ◽  
Lei Wang ◽  
Xiangguo Meng ◽  
Baolong Liang
Keyword(s):  
Coherent States ◽  
Wigner Distribution ◽  
Hermite Polynomials ◽  
Photon Number ◽  
Spin Ladder ◽  
Bernoulli Distribution ◽  
Ladder Operators ◽  
Spin Number ◽  
Photon Number Distribution ◽  
Spin Coherent States

Abstract Two new photon-modulated spin coherent states (SCSs) are introduced by operating the spin ladder operators J ± on the ordinary SCS in the Holstein-Primakoff realization and the nonclassicality is exhibited via their photon number distribution, second-order correlation function, photocount distribution and negativity of Wigner distribution. Analytical results show that the photocount distribution is a Bernoulli distribution and the Wigner functions are only associated with two-variable Hermite polynomials. Compared with the ordinary SCS, the photon-modulated SCSs exhibit more stronger nonclassicality in certain regions of the photon modulated number k and spin number j, which means that the nonclassicality can be enhanced by selecting suitable parameters.

scholarly journals Spin squeezing and entanglement in superposition of nonlinear spin coherent states

2018 ◽  
Vol 2 (5) ◽  
pp. 055001
Author(s):  
Azita Naji ◽  
Mojtaba Jafarpour ◽  
Fatemeh Sammak
Keyword(s):  
Coherent States ◽  
Spin Squeezing ◽  
Spin Coherent States
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