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Related papers: NPT Bound Entanglement- The Problem Revisited

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There has been much discussion recently regarding entanglement transformations in terms of local filtering operations and whether the optimal entanglement for an arbitrary two-qubit state could be realised. We introduce an experimentally…

Quantum Physics · Physics 2009-11-07 R. T. Thew , W. J. Munro

We study experimentally accessible lower bounds on entanglement measures based on entropic uncertainty relations. Experimentally quantifying entanglement is highly desired for applications of quantum simulation experiments to fundamental…

Quantum Physics · Physics 2021-05-25 Bjarne Bergh , Martin Gärttner

In $3\times 3$ dimensions, entangled mixed states that are positive under partial transposition (PPT states) must have rank at least four. They are well understood. We say that they have rank $(4,4)$ since a state $\rho$ and its partial…

Quantum Physics · Physics 2017-08-23 Leif Ove Hansen , Jan Myrheim

Entanglement and steering are used to describe quantum inseparabilities. Steerable states form a strict subset of entangled states. A natural question arises concerning how much territory steerability occupies entanglement for a general…

Quantum Physics · Physics 2021-09-01 Xiao-Gang Fan , Huan Yang , Fei Ming , Zhi-Yong Ding , Dong Wang , Liu Ye

The positivity of the partial transpose is in general only a necessary condition for separability. There exist quantum states that are not separable, but nevertheless are positive under partial transpose. States of this type are known as…

Quantum Physics · Physics 2019-08-14 Shan Ma , Matthew J. Woolley , Xiaojun Jia , Jing Zhang

Entanglement of any pure state of an N times N bi-partite quantum system may be characterized by the vector of coefficients arising by its Schmidt decomposition. We analyze various measures of entanglement derived from the generalized…

Quantum Physics · Physics 2009-11-07 Karol Zyczkowski , Ingemar Bengtsson

We derive a new inequality for entanglement for a mixed four-partite state. Employing this inequality, we present a one-shot lower bound for entanglement cost and prove that entanglement cost is strictly larger than zero for any entangled…

Quantum Physics · Physics 2009-11-11 Dong Yang , Michal Horodecki , Ryszard Horodecki , Barbara Synak-Radtke

The problem of determining whether a given quantum state is entangled lies at the heart of quantum information processing, which is known to be an NP-hard problem in general. Despite the proposed many methods such as the positive partial…

Quantum Physics · Physics 2018-07-18 Sirui Lu , Shilin Huang , Keren Li , Jun Li , Jianxin Chen , Dawei Lu , Zhengfeng Ji , Yi Shen , Duanlu Zhou , Bei Zeng

Tree tensor network states (TTNS) generalize the notion of having low Schmidt-rank to multipartite quantum states, through a parameter known as the bond dimension. This leads to succinct representations of quantum many-body systems with a…

Quantum Physics · Physics 2026-02-11 Benjamin Lovitz , Angus Lowe

The pure entangled state is of vital importance in the field of quantum information. The process of asymptotically extracting pure entangled states from many copies of mixed states via local operations and classical communication is called…

Quantum Physics · Physics 2019-08-09 Lilong Qian , Lin Chen , Delin Chu , Yi Shen

The amount of entanglement that exists in a parametric down-converted state is investigated in terms of all the degrees of freedom of the state. We quantify the amount of entanglement by the Schmidt number of the state, represented as a…

Quantum Physics · Physics 2020-05-13 Filippus S. Roux

We prove a lower bound for Schmidt numbers of bipartite mixed states. This lower bound can be applied easily to low rank bipartite mixed states. From this lower bound it is known that generic low rank bipartite mixed states have relatively…

Quantum Physics · Physics 2009-11-07 Hao Chen

We address an open question about the existence of entangled continuous-variable (CV) Werner states with positive partial transpose (PPT). We prove that no such state exists by showing that all PPT CV Werner states are separable. The…

Quantum Physics · Physics 2014-03-28 Daniel McNulty , Richard Tatham , Ladislav Mišta

We introduce a class of bipartite entangled continuous variable states that are positive under partial transposition operation, i.e., PPT bound entangled. These states are based on realistic preparation procedures in optical systems, being…

Quantum Physics · Physics 2015-06-15 F. E. S. Steinhoff , M. C. de Oliveira , J. Sperling , W. Vogel

In this paper we investigate the entanglement properties of the class of $\pi$-locally maximally entanglable ($\pi$-LME) states, which are also known as the "real equally weighted states" or the "hypergraph states". The $\pi$-LME states…

Quantum Physics · Physics 2014-10-15 Adi Makmal , Markus Tiersch , Vedran Dunjko , Shengjun Wu

Two families of bipartite mixed quantum states are studied for which it is proved that the number of members in the optimal-decomposition ensemble --- the ensemble realizing the entanglement of formation --- is greater than the rank of the…

Quantum Physics · Physics 2015-06-26 David P. DiVincenzo , Barbara M. Terhal , Ashish V. Thapliyal

We investigate relations between the ranks of marginals of multipartite quantum states. These are the Schmidt ranks across all possible bipartitions and constitute a natural quantification of multipartite entanglement dimensionality. We…

Quantum Physics · Physics 2014-04-29 Josh Cadney , Marcus Huber , Noah Linden , Andreas Winter

Multipartite quantum states that cannot be uniquely determined by their reduced states of all proper subsets of the parties exhibit some inherit `high-order' correlation. This paper elaborates this issue by giving necessary and sufficient…

Quantum Physics · Physics 2008-08-29 Yuan Feng , Runyao Duan , Mingsheng Ying

We develop a new method for entanglement detection in bipartite quantum states by using the violation of the rank-1-generated property of matrices. The positive-semidefinite matrices form a convex cone that has extremal elements of rank 1.…

Quantum Physics · Physics 2026-02-17 Aabhas Gulati

For a tripartite pure state superposed by two individual states, the bipartitely shared entanglement can always be achieved by local measurements of the third party. Consider the different aims of the third party, i.e. maximizing or…

Quantum Physics · Physics 2009-11-13 Chang-shui Yu , X. X. Yi , He-shan Song