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Related papers: Separability and distillability of multiparticle q…

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The state of an entangled q-bit pair is specified by 15 numerical parameters that are naturally regarded as the components of two 3-vectors and a $3\times3$-dyadic. There are easy-to-use criteria to check whether a given pair of 3-vectors…

Quantum Physics · Physics 2015-06-26 Berthold-Georg Englert , Nasser Metwally

Separability from the spectrum is a significant and ongoing research topic in quantum entanglement. In this study, we investigate properties related to absolute separability from the spectrum in qudits-qudits states in the bipartite states…

Quantum Physics · Physics 2024-08-22 Liang Xiong , Nung-Sing Sze

Quantum distillation is the task of concentrating quantum correlations present in 'N' imperfect copies using free operations by involving all 'P' parties sharing the quantum correlations. We present a threshold quantum distillation task…

Quantum Physics · Physics 2026-02-16 Shashank Gupta , William John Munro , Carlos Cid

We provide necessary and sufficient conditions for the partial transposition of bipartite harmonic quantum states to be nonnegative. The conditions are formulated as an infinite series of inequalities for the moments of the state under…

Quantum Physics · Physics 2009-11-11 E. Shchukin , W. Vogel

Given a finite set of linearly independent quantum states, an observer who examines a single quantum system may sometimes identify its state with certainty. However, unless these quantum states are orthogonal, there is a finite probability…

Quantum Physics · Physics 2009-09-25 Asher Peres , Daniel Terno

We study the closest disentangled state to a given entangled state in any system (multi-party with any dimension). We obtain the set of equations the closest disentangled state must satisfy, and show that its reduction is strongly related…

Quantum Physics · Physics 2007-05-23 Satoshi Ishizaka

In this paper, we study the separability of quantum states in bosonic system. Our main tool here is the "separability witnesses", and a connection between "separability witnesses" and a new kind of positivity of matrices--- "Power Positive…

Quantum Physics · Physics 2016-12-20 Nengkun Yu

We explore the subtle relationships between partial separability and entanglement of subsystems in multiqubit quantum states and give experimentally accessible conditions that distinguish between various classes and levels of partial…

Quantum Physics · Physics 2008-09-03 Michael Seevinck , Jos Uffink

States of sufficiently low purity are separable and cannot be entangled by unital (purity-non-generating) operations. Since high-purity states are experimentally demanding, it is natural to ask how much purity a state must possess to enable…

It is proven that recently introduced states with perfectly secure bits of cryptographic key (private states representing secure bit) [K. Horodecki et al., Phys. Rev. Lett. 94, 160502 (2005)] as well as its multipartite and higher dimension…

Quantum Physics · Physics 2007-11-07 Pawel Horodecki , Remigiusz Augusiak

Quantum state elimination measurements tell us what states a quantum system does not have. This is different from state discrimination, where one tries to determine what the state of a quantum system is, rather than what it is not. Apart…

We present a family of three-qubit quantum states with a basic local hidden variable model. Any von Neumann measurement can be described by a local model for these states. We show that some of these states are genuine three-partite…

Quantum Physics · Physics 2007-05-23 Geza Toth , Antonio Acin

In this paper, we show that an arbitrary separable state can be the output of a certain entanglement-breaking channel corresponding exactly to the input of a maximally entangled state. A necessary and sufficient separability criterion and…

Quantum Physics · Physics 2015-05-18 Bang-Hai Wang , Qin Li , Dongyang Long

A new family of polarized ensembles of random pure states is presented. These ensembles are obtained by linear superposition of two random pure states with suitable distributions, and are quite manageable. We will use the obtained results…

Mathematical Physics · Physics 2013-07-25 F. D. Cunden , P. Facchi , G. Florio

We show that all entangled Gaussian states of two infinite dimensional systems can be distilled to maximally entangled states in finite dimensions. The distillation protocol involves local squeezing operations, local homodyne measurements…

Quantum Physics · Physics 2007-05-23 Geza Giedke , Lu-Ming Duan , J. Ignacio Cirac , Peter Zoller

We show that bipartite quantum states of any dimension, which do not have a positive partial transpose, become 1-distillable when one adds an infinitesimal amount of bound entanglement. To this end we investigate the activation properties…

Quantum Physics · Physics 2009-11-07 Karl Gerd H. Vollbrecht , Michael M. Wolf

We prove experimentally the predicted existence of a three-qubit quantum state with genuine multipartite entanglement which can be certified solely from its separable two-qubit reduced density matrices. The qubits are encoded into different…

Quantum Physics · Physics 2020-08-05 Michal Mičuda , Robert Stárek , Jan Provazník , Olga Leskovjanová , Ladislav Mišta,

Condition for distinguishability of countably infinite number of pure states by a single measurement is given. Distinguishability is to be understood as possibility of an unambiguous measurement. For finite number of states, it is known…

Quantum Physics · Physics 2016-12-08 Ryuitiro Kawakubo , Tatsuhiko Koike

We explore classical to quantum transition of correlations by studying the quantum states located just outside of the classically-correlated-states-only neighborhood of the maximally mixed state (the largest separable ball (LSB)). We show…

Quantum Physics · Physics 2009-11-10 Somshubhro Bandyopadhyay , Vwani Roychowdhury

The absolutely separable (resp. PPT) states remain separable (resp. positive partial transpose) under any global unitary operation. We present a compact form of the extreme points in the sets of absolutely separable states and PPT states in…

Quantum Physics · Physics 2025-10-28 Zhiwei Song , Lin Chen