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1.
Nowadays, there are plenty of separability criteria which are used to detect entanglement. Many of them are limited to apply for some cases. In this paper, we propose a separability criterion for arbitrary multipartite pure state which is based on the rank of reduced density matrix. It is proved that the rank of reduced density matrices of a multipartite state is closely related to entanglement. In fact it can be used to characterize entanglement. Our separability criterion is a necessary and sufficient condition for detecting entanglement. Furthermore, it is able to help us find the completely separable form of a multipartite pure state according to some explicit examples. Finally it demonstrates that our method are more suitable for some specific case. Our separability criterion are simple to understand and it is operational. 相似文献
2.
The equivalence of multipartite quantum mixed states under
local unitary transformations is studied. A criterion for the
equivalence of non-degenerate mixed multipartite quantum states under
local unitary transformations is presented. 相似文献
3.
Agus Purwanto Heru Sukamto Lila Yuwana 《International Journal of Theoretical Physics》2018,57(8):2426-2436
We investigate entanglement and separability criteria of multipartite (n-partite) state by examining ranks of its reduced density matrices. Firstly, we construct the general formula to determine the criterion. A rank of origin density matrix always equals one, meanwhile ranks of reduced matrices have various ranks. Next, separability and entanglement criterion of multipartite is determined by calculating ranks of reduced density matrices. In this article we diversify multipartite state criteria into completely entangled state, completely separable state, and compound state, i.e. sub-entangled state and sub-entangledseparable state. Furthermore, we also shorten the calculation proposed by the previous research to determine separability of multipartite state and expand the methods to be able to differ multipartite state based on criteria above. 相似文献
4.
Zhao Jing Yun Zhao Hui Jing Naihuan Fei Shao-Ming 《International Journal of Theoretical Physics》2019,58(10):3181-3191
We investigate genuine multipartite entanglement in general multipartite systems. Based on the norms of the correlation tensors of a multipartite state under various partitions, we present an analytical and sufficient criterion for detecting the genuine four-partite entanglement. The results are generalized to arbitrary multipartite systems.
相似文献5.
Jian-Song Zhang Fen Liu Ai-Xi Chen 《International Journal of Theoretical Physics》2016,55(9):4016-4026
We investigate the effects of classical driving fields on the dynamics of purity, spin squeezing, and genuine multipartite entanglement (based on the Peres-Horodecki criterion ) of three two-level atoms within three separated cavities prepared in coherent states in the presence of decoherence. The three qubits are initially entangled and driven by classical fields. We obtain an analytical solution of the present system using the superoperator method. We find that the genuine multipartite entanglement measured by an entanglement monotone based on the Peres-Horodecki criterion can stay zero for a finite time and revive partially later. This phenomenon is similar to the sudden death of entanglement of two qubits and can be controlled efficiently by the classical driving fields. The amount of purity, spin squeezing, and genuine multipartite entanglement decrease with the increase of mean photon number of cavity fields. Particularly, the purity and genuine multipartite entanglement could be simultaneously improved by the classical driving fields. In addition, there is steady state genuine multipartite entanglement which can also be adjusted by the classical driving fields. 相似文献
6.
We introduce an operational procedure to determine, with arbitrary probability and accuracy, optimal entanglement witnesses for every multipartite entangled state. This method provides an operational criterion for separability which is asymptotically necessary and sufficient. Our results are also generalized to detect all different types of multipartite entanglement. 相似文献
7.
Duan LM 《Physical review letters》2011,107(18):180502
Dicke states represent a class of multipartite entangled states that can be generated experimentally with many applications in quantum information. We propose a method to experimentally detect genuine multipartite entanglement in the vicinity of arbitrary Dicke states. The detection scheme can be used to experimentally quantify the entanglement depth of many-body systems and is easy to implement as it requires measurement of only three collective spin operators. The detection criterion is strong as it heralds multipartite entanglement even in cases where the state fidelity goes down exponentially with the number of qubits. 相似文献
8.
The notion of the center-of-mass tomogram is introduced for describing the classical states of multipartite systems. The center-of-mass
tomographic-probability representation of the quantum states is used to calculate the fidelity of multipartite quantum states
in an explicit integral form. 相似文献
9.
Paolo Facchi, et al. [Phys. Rev. A77 (2008) 060304(R)] presented a maximally multipartite entangled state (MMES). Here, we give a criterion for the identification of maximally entangled four-qubit states. Using this criterion, we not only identify some existing maximally entangled four-qubit states in the literature, but also find several new maximally entangled four-qubit states as well. 相似文献
10.
ZHANG Rong ZHU Shi-Qun HAO Xiang 《理论物理通讯》2006,46(5):863-872
Three-dimensional Heisenberg model in the form of a tetrahedron lattice is investigated. The concurrence and multipartite entanglement are calculated through 2-concurrence C and 4-concurrence C4. The concurrence C and multipartite entanglement G4 depend on different coupling strengths Ji and are decreased when the temperature T is increased. For a symmetric tetrahedron lattice, the concurrence C is symmetric about J1 when J~ is negative while the multipartite entanglement G4 is symmetric about J1 when J2 〈 2. For a regular tetrahedron lattice, the concurrence G of ground state is 1/3 for ferromagnetic case while G = 0 for antiferromagnetic ca.se. However, there is no multipartitc entanglement since C4=0 in a regular tetrahedron lattice. The external magnetic field 13 can increase the maximum value of the concurrence GB and induce two or three peaks in Cn. There is a peak in the multipartite entanglement G4 B when G4B is varied as a function of the temperature T. This peak is mainly induced by the magnetic field B. 相似文献
11.
We propose a method of constructing the separability criteria for multipartite quantum states on the basis of entanglement witnesses. The entanglement witnesses are obtained by finding the maximal expectation values of Hermitian operators and then optimizing over all possible Hermitian operators. We derive a set of tripartite separability criteria for the four-qubit Greenberger–Horne–Zeilinger (GHZ) diagonal states. The derived criterion set contains four criteria that are necessary and sufficient for the tripartite separability of the highly symmetric four-qubit GHZ diagonal states; the criteria completely account for the numerically obtained boundaries of the tripartite separable state set. One of the criteria is just the tripartite separability criterion of the four-qubit generalized Werner states. 相似文献
12.
A protocol to transform Svetlichny's genuine multipartite correlations into standard isotropic form
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The standard isotropic correlations are widely used in the research of no-locality of quantum physics. We prove that any multipartite no-signaling correlation can be transformed into standard isotropic form through a randomization procedure, which does not change Svetlichny’s genuine multipartite correlation. For the tripartite correlations, each part with two inputs and two outcomes, we explicitly give the protocol and the proof of its validity. We then generalize the protocol to deal with the case of an N-partite. 相似文献
13.
N. S. Simonović 《Few-Body Systems》2006,38(2-4):139-145
In agreement with the Kohn theorem the relative motion (rel) of three electrons in a two-dimensional parabolic trap separates
from the centre-of-mass (CM) motion. By introducing new coordinates the Hamiltonian for relative motion in the approximation
of non-interacting electrons can be taken to the normal form. The eigenstates of the normalized Hamiltonian are products of
the Fock-Darwin states for normal modes. The energy levels for relative motion are obtained by diagonalizing the exact Hamiltonian
in the eigenbasis for the non-interacting case. In this basis the interaction matrix elements can be obtained in the analytical
form. Since the rank of the Hamiltonian matrix is significantly reduced, the calculations are faster and more accurate than
those for the full (CM + rel) motion. This advantage is especially important for the calculations of excited states and the
analysis of energy spectra. 相似文献
14.
Yu Guo 《Entropy (Basel, Switzerland)》2022,24(3)
A crucial issue in quantum communication tasks is characterizing how quantum resources can be quantified and distributed over many parties. Consequently, entanglement has been explored extensively. However, there are few genuine multipartite entanglement measures and whether it is monogamous is so far unknown. In this work, we explore the complete monogamy of genuine multipartite entanglement measure (GMEM) for which, at first, we investigate a framework for unified/complete GMEM according to the unified/complete multipartite entanglement measure we proposed in 2020. We find a way of inducing unified/complete GMEM from any given unified/complete multipartite entanglement measure. It is shown that any unified GMEM is completely monogamous, and any complete GMEM that is induced by given complete multipartite entanglement measure is completely monogamous. In addition, the previous GMEMs are checked under this framework. It turns out that the genuinely multipartite concurrence is not as good of a candidate as GMEM. 相似文献
15.
《Physics letters. A》2002,306(1):14-20
We present a generalized partial transposition separability criterion for the density matrix of a multipartite quantum system. This criterion comprises as special cases the famous Peres–Horodecki criterion and the recent realignment criterion in [O. Rudolph, quant-ph/0202121] and [K. Chen, L.A. Wu, quant-ph/0205017]. It involves only straightforward matrix manipulations and is easy to apply. A quantitative measure of entanglement based on this criterion is also obtained. 相似文献
16.
Gühne O 《Physical review letters》2004,92(11):117903
We derive a family of necessary separability criteria for finite-dimensional systems based on inequalities for variances of observables. We show that every pure bipartite entangled state violates some of these inequalities. Furthermore, a family of bound entangled states and true multipartite entangled states can be detected. The inequalities also allow us to distinguish between different classes of true tripartite entanglement for qubits. We formulate an equivalent criterion in terms of covariance matrices. This allows us to apply criteria known from the regime of continuous variables to finite-dimensional systems. 相似文献
17.
Quantum Fisher information is related to the problem of parameter estimation.Recently,a criterion has been proposed for entanglement in multipartite systems based on quantum Fisher information.This paper studies the behaviours of quantum Fisher information in the quantum kicked top model,whose classical correspondence can be chaotic.It finds that,first,detected by quantum Fisher information,the quantum kicked top is entangled whether the system is in chaotic or in regular case.Secondly,the quantum Fisher information is larger in chaotic case than that in regular case,which means,the system is more sensitive in the chaotic case. 相似文献
18.
Preparation of entangled squeezed states and quantification of their entanglement 总被引:3,自引:0,他引:3
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We propose a scheme for generating bipartite and multipartite entangled squeezed states via the Jaynes-Cummings model with large detuning. Bipartite entanglement of these entangled states is quantified by the concurrence. We also use the N-tangle to compute multipartite entanglement of these multipartite entangled squeezed states. Finally we discuss two limiting cases which arise from r→∞ and r→0, in which the multipartite entangled squeezed state reduces correspondingly into an N-qubit Greenberger-Horne-Zeilinger state and an N-qubit W state. 相似文献
19.
20.
Mutually unbiased bases, mutually unbiased measurements and general symmetric informationally complete measurements are three related concepts in quantum information theory. We investigate multipartite systems using these notions and present some criteria detecting entanglement of arbitrary high dimensional multi-qudit systems and multipartite systems of subsystems with different dimensions. It is proved that these criteria can detect the k-nonseparability(k is even) of multipartite qudit systems and arbitrary high dimensional multipartite systems of m subsystems with different dimensions.We show that they are more efficient and wider of application range than the previous ones. They provide experimental implementation in detecting entanglement without full quantum state tomography. 相似文献