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A new criterion necessary and sufficient for the separability of pure bipartite systems for arbitrary finite dimensions is demonstrated; and the corresponding finer quantitative measures or characterizations of entanglement (beyond mere…

Quantum Physics · Physics 2013-04-22 Che-Hsu Li

Necessary and sufficient conditions for bipartite entanglement are derived, which apply to arbitrary Hilbert spaces. Motivated by the concept of witnesses, optimized entanglement inequalities are formulated solely in terms of arbitrary…

Quantum Physics · Physics 2009-11-13 J. Sperling , W. Vogel

The ability to generate bipartite entanglement in quantum computing technologies is widely regarded as pivotal. However, the role of genuinely multipartite entanglement is much less understood than bipartite entanglement, particularly in…

Quantum Physics · Physics 2025-02-24 Gopal Chandra Santra , Sudipto Singha Roy , Daniel J. Egger , Philipp Hauke

Bound entanglement is a special form of quantum entanglement that cannot be used for distillation, i.e., the local transformation of copies of arbitrarily entangled states into a smaller number of approximately maximally entangled states.…

Quantum Physics · Physics 2025-08-01 Beatrix C. Hiesmayr , Christopher Popp , Tobias C. Sutter

A universal entangler is quantum gate able to transform any disentangled state in an entangled state. Although universal entanglers are abundant in arbitrary high dimensional spaces, to verify if a quantum gate is a universal entangler is a…

Quantum Physics · Physics 2024-09-19 F. V. Mendes , R. V. Ramos

In this paper we initiate the study of entanglement-breaking (EB) superchannels. These are processes that always yield separable maps when acting on one side of a bipartite completely positive (CP) map. EB superchannels are a generalization…

Quantum Physics · Physics 2020-07-21 Senrui Chen , Eric Chitambar

Fernando Galve \emph{et al.} $[Phys. Rev. Lett. \textbf{110}, 010501 (2013)]$ introduced discording power for a two-qubit unitary gate to evaluate its capability to produce quantum discord, and found that a $\pi/8$ gate has maximal…

Quantum Physics · Physics 2013-07-16 Zhe Guan , Huan He , Yong-Jian Han , Chuan-Feng Li , Guang-Can Guo

Monogamy of entanglement is generally discussed using a bipartite entanglement measure as an upper bound. Here we discuss a new kind of monogamous relation where the upper bound is given by a multipartite measure of entanglement, the…

Quantum Physics · Physics 2013-03-27 Marcio F. Cornelio

We show that bipartite entanglement distribution (or entanglement of assistance) in multipartite quantum systems is by nature polygamous. We first provide an analytic upper bound for the concurrence of assistance in bipartite quantum…

Quantum Physics · Physics 2009-08-06 Jeong San Kim

The dynamics of a system composed by two pairs of dipolarly coupled two-level atoms is exactly studied. We show that the initial entanglement stored in a couple of atoms not directly interacting is fully transferred to the other pair in a…

Quantum Physics · Physics 2012-06-06 Riccardo Messina , Anna Napoli , Antonino Messina

The information obtained from the operation of a quantum gate on only two complementary sets of input states is sufficient to estimate the quantum process fidelity of the gate. In the case of entangling gates, these conditions can be used…

Quantum Physics · Physics 2017-08-23 Holger F. Hofmann , Ryo Okamoto , Shigeki Takeuchi

Dissipative processes in physics are usually associated with non-unitary actions. However, the important resource of entanglement is not invariant under general unitary transformations, and is thus susceptible to unitary "dissipation". In…

Quantum Physics · Physics 2015-05-30 Allan I. Solomon

Absolutely Maximally Entangled (AME) states are those multipartite quantum states that carry absolute maximum entanglement in all possible partitions. AME states are known to play a relevant role in multipartite teleportation, in quantum…

Quantum Physics · Physics 2015-12-02 Dardo Goyeneche , Daniel Alsina , José I. Latorre , Arnau Riera , Karol Życzkowski

We show that bipartite entanglements involving non-orthogonal states are {\it necessarily nonmaximally} entangled, however {\it small} the non-orthogonality may be. How the deviation from maximal entanglement is related to nonorthogonality…

Quantum Physics · Physics 2007-05-23 Dipankar Home , M K Samal

We investigate unitary operators acting on a tensor product space, with the property that the quantum channels they generate, via the Stinespring dilation theorem, are of a particular type, independently of the state of the ancilla system…

Quantum Physics · Physics 2016-07-26 Julien Deschamps , Ion Nechita , Clement Pellegrini

We provide upper bound on the maximal rate at which irreversible quantum dynamics can generate entanglement in a bipartite system. The generator of irreversible dynamics consists of a Hamiltonian and dissipative terms in Lindblad form. The…

Quantum Physics · Physics 2015-08-12 Anna Vershynina

Amount of entanglement carried by a quantum bipartite state is usually evaluated in terms of concurrence (see Ref. 1). We give a physical interpretation of concurrence that reveals a way of its direct measurement and discuss possible…

Quantum Physics · Physics 2016-08-16 Alexander Klyachko , Barış Öztop , Alexander S. Shumovsky

An asymptotic entanglement measure for any bipartite states is derived in the light of the dense coding capacity optimized with respect to local quantum operations and classical communications. General properties and some examples with…

Quantum Physics · Physics 2015-06-26 Tohya Hiroshima

How entangled is a randomly chosen bipartite stabilizer state? We show that if the number of qubits each party holds is large the state will be close to maximally entangled with probability exponentially close to one. We provide a similar…

Quantum Physics · Physics 2007-05-23 Graeme Smith , Debbie Leung

We construct a quantum machine which, by using asymmetric cloner, deals with disentangling and broadcasting entanglement in a single unitary evolution. The attainable maximum value of the scaling parameter $s$ for disentangling is identical…

Quantum Physics · Physics 2007-05-23 Yafei Yu , Jian Feng , Xiaoqing Zhou , Mingsheng Zhan