English
Related papers

Related papers: Unveiling NPT bound problem: From Distillability S…

200 papers

Entanglement and nonlocality are both fundamental aspects of quantum theory, and play a prominent role in quantum information science. The exact relation between entanglement and nonlocality is however still poorly understood. Here we make…

Quantum Physics · Physics 2012-01-24 Tamas Vertesi , Nicolas Brunner

Ever since entanglement was identified as a computational and cryptographic resource, effort has been made to find an efficient way to tell whether a given density matrix represents an unentangled, or separable, state. Essentially, this is…

Data Structures and Algorithms · Computer Science 2007-05-23 Lawrence M. Ioannou

This paper tries to probe the relation between the local distinguishability of orthogonal quantum states and the distillation of entanglement. An new interpretation for the distillation of entanglement and the distinguishability of…

Quantum Physics · Physics 2007-05-23 Ping-Xing Chen , Cheng-Zu Li

Necessary and sufficient observable conditions for the nonnegativity of all partial transpositions of multi-mode quantum states are derived. The result is a hierarchy of inequalities for minors in terms of moments of the given state.…

Quantum Physics · Physics 2009-11-13 E. Shchukin , W. Vogel

Via nonlocality distillation, a number of copies of a given nonlocal correlation can be turned into a new correlation displaying a higher degree of nonlocality. Apart from its clear relevance in situations where nonlocality is a resource,…

Quantum Physics · Physics 2019-07-10 S. G. A. Brito , M. G. M. Moreno , A. Rai , R. Chaves

The phenomenon of quantum entanglement marks one of the furthest departures from classical physics and is indispensable for quantum information processing. Despite its fundamental importance, the distribution of entanglement over long…

Quantum Physics · Physics 2021-07-27 Sebastian Ecker , Philipp Sohr , Lukas Bulla , Marcus Huber , Martin Bohmann , Rupert Ursin

We study entanglement-related properties of random quantum states which are unitarily invariant, in the sense that their distribution is left unchanged by conjugation with arbitrary unitary operators. In the large matrix size limit, the…

Mathematical Physics · Physics 2018-07-09 Ion Nechita

Multiqubit positive-partial-transpose (PPT) entangled states play an important role in quantum information theory. We characterize such states of minimum rank in three-qubit system, namely rank four. Depending on whether the Lorentz…

Quantum Physics · Physics 2026-05-20 Yonggang Cheng , Lin Chen

The uncertainty relation is one of the key ingredients of quantum theory. Despite the great efforts devoted to this subject, most of the variance-based uncertainty relations are state-dependent and suffering from the triviality problem of…

Quantum Physics · Physics 2018-03-08 Chen Qian , Jun-Li Li , Cong-Feng Qiao

Employing a recently proposed separability criterion we develop analytical lower bounds for the concurrence and for the entanglement of formation of bipartite quantum systems. The separability criterion is based on a nondecomposable…

Quantum Physics · Physics 2007-05-23 Heinz-Peter Breuer

We obtain the necessary and sufficient separability and distillability conditions of mixtures of a maximally entangled state and the completely separable state in relativistic setting. In an inertial frame we study the entanglement under…

Quantum Physics · Physics 2012-01-10 Shahpoor Moradi

Entanglement is a fundamental feature of quantum mechanics, playing a crucial role in quantum information processing. However, classifying entangled states, particularly in the mixed-state regime, remains a challenging problem, especially…

Quantum theory puts forward phenomena unexplainable by classical physics - or information, for that matter. A prominent example is non-locality. Non-local correlations cannot be explained, in classical terms, by shared information but only…

Quantum Physics · Physics 2014-08-26 Helen Ebbe , Stefan Wolf

The partial transposition(PT) operation is an effecient tool in detecting the inseparability of a mixed state. We give an explicit formula for the PT operation for the continuous variable states in Fock space. We then give the necessary and…

Quantum Physics · Physics 2013-05-29 Wang Xiang-Bin , Matsumoto Keiji , Tomita Akihisa

We consider the transformation of multi-partite states in the single copy setting under positive-partial-transpose-preserving operations (PPT-operations) and obtain both qualitative and quantitative results. Firstly, for some pure state…

Quantum Physics · Physics 2007-05-23 Satoshi Ishizaka , Martin B. Plenio

We propose in this work a practical approach to address the longstanding and challenging problem of quantum separability, leveraging the correlation matrices of generic observables. General separability conditions are obtained by dint of…

Quantum Physics · Physics 2025-05-07 Ma-Cheng Yang , Cong-Feng Qiao

Using a geometric measure of entanglement quantification based on Euclidean distance of the Hermitian matrices, we obtain the minimum distance between a bipartite bound entangled $n$- qudit density matrix and the maximally mixed state.This…

Quantum Physics · Physics 2017-09-26 Shreya Banerjee , Aryaman A. Patel , Prasanta K. Panigrahi

In quantum information theory, it is widely believed that entanglement concentration for bipartite pure states is asymptotically reversible. In order to examine this, we give a precise formulation of the problem, and show a trade-off…

Quantum Physics · Physics 2013-10-01 Wataru Kumagai , Masahito Hayashi

We develop two general approaches to characterising the manipulation of quantum states by means of probabilistic protocols constrained by the limitations of some quantum resource theory. First, we give a general necessary condition for the…

Quantum Physics · Physics 2023-06-23 Bartosz Regula

Bipartite quantum states are classified into three categories: separable states, bound entangled states, and free entangled states. It is of great importance to characterize these families of states for the development of quantum…

Quantum Physics · Physics 2007-05-23 Tohya Hiroshima