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Related papers: $n$ qubits can be entangled in two different ways

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We extend the matrix decomposition method(MDM) in classifying the $2\times N\times N$ truly entangled states to $2\times M\times N$ system under the condition of stochastic local operations and classical communication. It is found that the…

Quantum Physics · Physics 2018-01-11 Jun-Li Li , Cong-Feng Qiao

In [Science 340, 1205, 7 June (2013)], via polytopes Michael Walter et al. proposed a sufficient condition detecting the genuinely entangled pure states. In this paper, we indicate that generally, the coefficient vector of a pure product…

Quantum Physics · Physics 2018-10-10 Dafa Li

Lamata et al. use an inductive approach to classify the entangled pure states of four qubits under stochastic local operations and classical communication (SLOCC) [PRA 75(2), 022318 (2007)]. The inductive method yields a priori ten…

Quantum Physics · Physics 2017-03-01 Miriam Backens

We characterize the positive maps detecting the entangled bipartite states of n x n qubits that are diagonal with respect to the orthonormal basis constructed by tensor products of Pauli matrices acting on the totally symmetric state. We…

Mathematical Physics · Physics 2013-01-16 Fabio Benatti , Mahya Karbalaii

We put forward an alternative approach to the SLOCC classification of entanglement states of three-qubit and four-qubit systems. By directly solving matrix equations, we obtain the relations satisfied by the amplitudes of states. The…

Quantum Physics · Physics 2009-11-13 D. Li , X. Li , H. Huang , X. Li

If a pure state of a qubit pair is developed over the four basis states, it is known that an equality between the four coefficients of that development exists if and only if that state is unentangled. This paper considers an arbitrary pure…

Quantum Physics · Physics 2019-09-19 Alain Deville , Yannick Deville

We solve the entanglement classification under stochastic local operations and classical communication (SLOCC) for general n-qubit states. For two arbitrary pure n-qubit states connected via local operations, we establish an equation…

Quantum Physics · Physics 2012-05-07 Xiangrong Li , Dafa Li

We prove that the vast majority of symmetric states of qubits can be decomposed in a unique way into a superposition of spin 1/2 coherent states. For the case of two qubits, the proposed decomposition reproduces the Schmidt decomposition…

Quantum Physics · Physics 2015-06-25 A. Mandilara , T. Coudreau , A. Keller , P. Milman

Entanglement is widely considered the cornerstone of quantum information and an essential resource for relevant quantum effects, such as quantum teleportation, quantum cryptography, or the speed-up of quantum computing, as in Shor's…

Quantum Physics · Physics 2017-01-13 M. Sanz , I. L. Egusquiza , R. Di Candia , H. Saberi , L. Lamata , E. Solano

We first present a generalized criterion for maximally entangled states of 2, 3, 4, 5, 6, 8 and in theory to arbitrary-number qubits. By this criterion, some known highly entangled multi-qubit states are examined and a new genuine…

Quantum Physics · Physics 2015-06-04 Xinwei Zha , Chenzhi Yuan , Yanpeng Zhang

We undertake experimental detection of the entanglement present in arbitrary three-qubit pure quantum states on an NMR quantum information processor. Measurements of only four observables suffice to experimentally differentiate between the…

Quantum Physics · Physics 2018-09-06 Amandeep Singh , Harpreet Singh , Kavita Dorai , Arvind

Quantum states are represented by positive semidefinite Hermitian operators with unit trace, known as density matrices. An important subset of quantum states is that of separable states, the complement of which is the subset of…

Mathematical Physics · Physics 2020-12-04 Grigoriy Blekherman , H. M. Bharath

A complete analysis of entangled bipartite qutrit pure states is carried out based on a simple entanglement measure. An analysis of all possible extremally entangled pure bipartite qutrit states is shown to reduce, with the help of SLOCC…

Quantum Physics · Physics 2009-11-11 Feng Pan , Guoying Lu , J. P. Draayer

We discuss the concept of how entanglement changes with respect to different factorizations of the total algebra which describes the quantum states. Depending on the considered factorization a quantum state appears either entangled or…

Quantum Physics · Physics 2011-11-15 Walter Thirring , Reinhold A. Bertlmann , Philipp Köhler , Heide Narnhofer

We reduce the necessary and sufficient biseparable conditions of the four qubit cluster diagonal state to concise forms. Only 4 out of the 15 parameters are proved to be relevant in specifying the genuine entanglement of the state. Using…

Quantum Physics · Physics 2013-05-30 Xiao-yu Chen , Ping Yu , Li-zhen Jiang , Mingzhen Tian

The correlation matrix (CM) criterion is a recently derived powerful sufficient condition for the presence of entanglement in bipartite quantum states of arbitrary dimensions. It has been shown that it can be stronger than the positive…

Quantum Physics · Physics 2009-11-13 Julio I. de Vicente

We provide a classification of entangled states that uses new discrete entanglement invariants. The invariants are defined by algebraic properties of linear maps associated with the states. We prove a theorem on a correspondence between the…

Quantum Physics · Physics 2013-01-08 Roman V. Buniy , Thomas W. Kephart

We introduce a protocol to classify three-qubit pure states into different entanglement classes and implement it on an NMR quantum processor. The protocol is designed in such a way that the experiments performed to classify the states can…

Quantum Physics · Physics 2024-11-07 Vaishali Gulati , Arvind , Kavita Dorai

A system of three or four particle can be entangled in a number of different ways. It may be the case that only subsets of the particles are entangled, and these subsets are not entangled with each other. It may also be the case that the…

Quantum Physics · Physics 2026-04-02 Mark Hillery

Graph states represent a significant class of multi-partite entangled quantum states with applications in quantum error correction, quantum communication, and quantum computation. In this work, we introduce a novel formalism called the…

Quantum Physics · Physics 2025-07-16 Sameer Sharma