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Related papers: Separability criteria based on the Weyl operators

200 papers

We analyze and compare the mathematical formulations of the criterion for separability for bipartite density matrices and the Bell inequalities. We show that a violation of a Bell inequality can formally be expressed as a witness for…

Quantum Physics · Physics 2009-10-31 Barbara M. Terhal

We demonstrate how to efficiently derive a broad class of inequalities for entanglement detection in multi-mode continuous variable systems. The separability conditions are established from partial transposition (PT) in combination with…

Quantum Physics · Physics 2015-05-13 Qingqing Sun , Hyunchul Nha , M. Suhail Zubairy

The concept of entanglement splitting is introduced by asking whether it is possible for a party possessing half of a pure bipartite quantum state to transfer some of his entanglement with the other party to a third party. We describe the…

Quantum Physics · Physics 2009-10-31 Dagmar Bruss

We build a machine learning model to detect correlations in a three-qubit system using a neural network trained in an unsupervised manner on randomly generated states. The network is forced to recognize separable states, and correlated…

Quantum Physics · Physics 2024-08-20 Mateusz Krawczyk , Jarosław Pawłowski , Maciej M. Maśka , Katarzyna Roszak

Quantumness and separability criteria for continuous variable systems are discussed for the case of a noncommutative (NC) phase-space. In particular, the quantum nature and the entanglement configuration of NC two-mode Gaussian states are…

Quantum Physics · Physics 2015-10-13 Alex E. Bernardini , Catarina Bastos , Orfeu Bertolami , Nuno C. Dias , João N. Prata

We present three different matrix bases that can be used to decompose density matrices of $d$--dimensional quantum systems, so-called qudits: the \emph{generalized Gell-Mann matrix basis}, the \emph{polarization operator basis}, and the…

Quantum Physics · Physics 2009-11-13 Reinhold A. Bertlmann , Philipp Krammer

One of the fundamental concepts of quantum information theory is that of entanglement purification; that is, the transformation of a partially entangled state into a smaller-dimensional, more completely entangled state. Of particular…

Quantum Physics · Physics 2008-02-03 Eric M. Rains

This thesis is a multidisciplinary contribution to the information theory of single-particle Coulomb systems in their relativistic and not relativistic description, to the theory of special functions of mathematical physics with the…

Quantum Physics · Physics 2011-03-18 Daniel Manzano

Transfer of entanglement and information is studied for quantum teleportation of an unknown entangled state through noisy quantum channels. We find that the quantum entanglement of the unknown state can be lost during the teleportation even…

Quantum Physics · Physics 2009-01-23 Jinhyoung Lee , M. S. Kim

Quantum entanglement is widely recognized as one of the key resources for the advantages of quantum information processing, including universal quantum computation, reduction of communication complexity or secret key distribution. However,…

We introduce a protocol to classify three-qubit pure states into different entanglement classes and implement it on an NMR quantum processor. The protocol is designed in such a way that the experiments performed to classify the states can…

Quantum Physics · Physics 2024-11-07 Vaishali Gulati , Arvind , Kavita Dorai

Entanglement witnesses (EWs) are a collection of observables that can characterize separable states and, experimentally, estimating EWs can verify entangled states. In this work, we show that a fixed measurement setting on a multipartite…

Quantum Physics · Physics 2026-05-29 Jaemin Kim , Anindita Bera , Dariusz Chruściński , Joonwoo Bae

We discuss two qualities of quantum systems: various correlations existing between their subsystems and the distingushability of different quantum states. This is then applied to analysing quantum information processing. While quantum…

Quantum Physics · Physics 2015-05-13 Vlatko Vedral

The work is intended to represent some interesting and apparently peculiar features of entangled system in both pure as well as mixed states level. In the pure state level, we are largely concerned about the existence and characteristics of…

Quantum Physics · Physics 2008-05-15 Indrani Chattopadhyay

We investigate the norms of the Bloch vectors for any quantum state with subsystems less than or equal to four. Tight upper bounds of the norms are obtained, which can be used to derive tight upper bounds for entanglement measure defined by…

Quantum Physics · Physics 2019-03-27 Ming Li , Zong Wang , Jing Wang , Shuqian Shen , Shao-ming Fei

The state of a quantum system, consisting of two distinct subsystems, is called separable if it can be prepared by two distant experimenters who receive instructions from a common source, via classical communication channels. A necessary…

Quantum Physics · Physics 2009-10-30 Asher Peres

The $W$ state, a canonical representative of multipartite quantum entanglement, plays a crucial role in quantum information science due to its robust entanglement properties. Quantum uncertainty relations, on the other hand, are a…

Quantum Physics · Physics 2025-11-21 Zhi-Jie Liu , Hao-Nan Qiang , Jie Zhou , Mi Xie , Jing-Ling Chen

We study genuine tripartite entanglement and multipartite entanglement in arbitrary $n$-partite quantum systems based on complete orthogonal basis (COB). While the usual Bloch representation of a density matrix uses three types of…

Quantum Physics · Physics 2024-02-21 Hui Zhao , Jia Hao , Jing Li , Shao-Ming Fei , Naihuan Jing , Zhi-Xi Wang

We introduce a general framework for detecting genuine multipartite entanglement and non full-separability in multipartite quantum systems of arbitrary dimensions based on correlation tensors. Regarding genuine multipartite entanglement our…

Quantum Physics · Physics 2011-12-08 Julio I. de Vicente , Marcus Huber

In any bipartition of a quantum state, it is proved that the negative values of the conditional version of sandwiched Tsallis relative entropy necessarily implies quantum entanglement. For any N, the separability ranges in the $1:N-1$…

Quantum Physics · Physics 2015-09-28 Anantha S Nayak , Sudha , A. K. Rajagopal , A. R. Usha Devi