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Invertible local transformations of a multipartite system are used to define equivalence classes in the set of entangled states. This classification concerns the entanglement properties of a single copy of the state. Accordingly, we say…

Quantum Physics · Physics 2009-11-06 W. Dür , G. Vidal , J. I. Cirac

We propose an entanglement sharing protocol based on separable states. Initially, two parties, Alice and Bob, share a two-mode separable Gaussian state. Alice then splits her mode into two separable modes and distributes them between two…

Quantum Physics · Physics 2016-05-04 Ladislav Mišta

Genuineness and distillability of entanglement play a key role in quantum information tasks, and they are easily disturbed by the noise. We construct a family of multipartite states without genuine entanglement and distillability sudden…

Quantum Physics · Physics 2021-02-05 Mengyao Hu , Lin Chen

No pure entangled state can be distilled from a $2\otimes 2$ or $2\otimes 3$ mixed state by separable operations. In $3\otimes 3$, pure entanglement can be distilled by separable operation but not by LOCC. In this letter, we proved the…

Quantum Physics · Physics 2025-08-21 Indranil Biswas , Atanu Bhunia , Indrani Chattopadhyay , Debasis Sarkar

Alice, Bob, and Eve share a pure quantum state. We introduce the notion of state degradability by asking whether the joint density of Alice and Eve can be transformed to the joint density of Alice and Bob by processing Eve's part through a…

Quantum Physics · Physics 2014-05-09 Chi-Hang Fred Fung , Chi-Kwong Li , Nung-Sing Sze , H. F. Chau

One of the most important problems in quantum information is the separability problem, which asks whether a given quantum state is separable. We investigate multipartite states of rank at most four which are PPT (i.e., all their partial…

Quantum Physics · Physics 2015-06-12 Lin Chen , Dragomir Z. Djokovic

Absolutely separable states $\varrho$ remain separable under arbitrary unitary transformations $U \varrho U^{\dag}$. By example of a three qubit system we show that in multipartite scenario neither full separability implies bipartite…

Quantum Physics · Physics 2017-08-21 Sergey N. Filippov , Kamil Yu. Magadov , Maria Anastasia Jivulescu

We introduce a formalism that connections entanglement witnesses and the distillation and activation properties of a state. We apply this formalism to two cases: First, we rederive the results presented in quant-ph/0104095 by Eggeling et…

Quantum Physics · Physics 2009-11-07 B. Kraus , M. Lewenstein , J. I. Cirac

There is an ongoing effort to quantify entanglement of quantum pure states for systems with more than two subsystems. We consider three approaches to this problem for three-qubit states: choosing a basis which puts the state into a standard…

Quantum Physics · Physics 2009-11-06 Todd A. Brun , Oliver Cohen

We show that no EPR-like bipartite entanglement can be distilled from a tripartite Haar random state $|\Psi\rangle_{ABC}$ by local unitaries or local operations when each subsystem $A$, $B$, or $C$ has fewer than half of the total qubits.…

Quantum Physics · Physics 2026-05-21 Zhi Li , Takato Mori , Beni Yoshida

Quantum network states are multipartite states built from distributing pairwise entanglement among parties and underpin the paradigm of quantum networks for quantum information processing. In this work we introduce the problem of partial…

Quantum Physics · Physics 2025-09-30 Aitor Balmaseda , Julio I. de Vicente

We introduce the concentrated information of tripartite quantum states. For three parties Alice, Bob, and Charlie, it is defined as the maximal mutual information achievable between Alice and Charlie via local operations and classical…

Quantum Physics · Physics 2015-07-22 Alexander Streltsov , Soojoon Lee , Gerardo Adesso

We analyze a class of entangled states for bipartite $d \otimes d$ systems, with $d$ non-prime. The entanglement of such states is revealed by the construction of canonically associated entanglement witnesses. The structure of the states is…

Quantum Physics · Physics 2009-11-13 M. Piani , C. Mora

We find that the asymptotic entanglement of assistance of a general bipartite mixed state is equal to the smaller of its two local entropies. Our protocol gives rise to the asymptotically optimal EPR pair distillation procedure for a given…

Quantum Physics · Physics 2007-05-23 John A. Smolin , Frank Verstraete , Andreas Winter

The reduction criterion is a well known necessary condition for separable states, and states violating this condition are entangled and also 1-distillable. In this paper we introduce a new set of necessary conditions for separability of…

Quantum Physics · Physics 2009-11-11 William Hall

A nice and interesting property of any pure tensor-product state is that each such state has distillable entangled states at an arbitrarily small distance $\epsilon$ in its neighborhood. We say that such nearby states are…

Quantum Physics · Physics 2017-01-27 Michel Boyer , Aharon Brodutch , Tal Mor

We devise a protocol in which general non-classical multipartite correlations produce a physically relevant effect, leading to the creation of bipartite entanglement. In particular, we show that the relative entropy of quantumness, which…

We show that all quantum states that do not have a positive partial transpose are distillable via channels, which preserve the positivity of the partial transpose. The question whether NPT bound entanglement exist is therefore closely…

Quantum Physics · Physics 2009-11-07 Tilo Eggeling , Karl Gerd H. Vollbrecht , Reinhard F. Werner , Michael M. Wolf

A bipartite state which is secretly chosen from a finite set of known entangled pure states cannot be immediately useful in standard quantum information processing tasks. To effectively make use of the entanglement contained in this unknown…

Quantum Physics · Physics 2015-05-14 Yangjia Li , Runyao Duan , Mingsheng Ying

We provide an example of distillable bipartite mixed state such that, even in the asymptotic limit, more pure-state entanglement is required to create it than can be distilled from it. Thus, we show that the irreversibility in the processes…

Quantum Physics · Physics 2009-11-07 G. Vidal , J. I. Cirac