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Related papers: Optimal entanglement witnesses based on local orth…

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We study the entanglement detection by using mutually unbiased measurements and provide a quantum separability criterion that can be experimentally implemented for arbitrary $d$-dimensional bipartite systems. We show that this criterion is…

Quantum Physics · Physics 2015-06-22 Bin Chen , Teng Ma , Shao-Ming Fei

We investigate bound entanglement in three-qubit mixed states which are diagonal in the Greenberger-Horne-Zeilinger (GHZ) basis. Entanglement in these states is detected using entanglement witnesses and the analysis focuses on states…

Quantum Physics · Physics 2024-11-05 Vaishali Gulati , Gayatri Singh , Kavita Dorai

For any bipartite systems, a universal entanglement witness of rank-4 for pure states is obtained and a class of finite rank entanglement witnesses is constructed. In addition, a method of detecting entanglement of a state only by entries…

Quantum Physics · Physics 2010-10-25 Xiaofei Qi , Jinchuan Hou

We present a new measure of entanglement for mixed states. It can be approximately computable for every state and can be used to quantify all different types of multipartite entanglement. We show that it satisfies the usual properties of a…

Quantum Physics · Physics 2007-05-23 Fernando G. S. L. Brandao , Reinaldo O. Vianna

A new family of positive, trace-preserving maps is introduced. It is defined using the mutually unbiased measurements, which generalize the notion of mutual unbiasedness of orthonormal bases. This family allows one to define entanglement…

Quantum Physics · Physics 2021-11-30 Katarzyna Siudzińska , Dariusz Chruściński

We present a significantly improved scheme of entanglement detection inspired by local uncertainty relations for a system consisting of two qubits. Developing the underlying idea of local uncertainty relations, namely correlations, we…

Quantum Physics · Physics 2016-08-16 Christian Kothe , Gunnar Björk

We discuss the use of the Gilbert algorithm to tailor entanglement witnesses for unextendibleproduct basis bound entangled states (UPB BE states). The method relies on the fact that an optimalentanglement witness is given by a plane…

Quantum Physics · Physics 2020-01-22 Marcin Wieśniak , Palash Pandya , Omer Sakarya , Bianka Woloncewicz

The generation of spin-entangled electrons is an important prerequisite for future solid-state quantum technologies. Cooper pairs in a superconductor can be split into separate electrons in a spin-singlet state, however, detecting their…

Mesoscale and Nanoscale Physics · Physics 2021-12-23 Minh Tam , Christian Flindt , Fredrik Brange

We interpret multi-partite genuine entanglement witnesses as simultaneous positivity of various maps arising from them. We apply this result to multi-qubit {\sf X}-shaped Hermitian matrices, and characterize the conditions for them to be…

Quantum Physics · Physics 2016-04-20 Kyung Hoon Han , Seung-Hyeok Kye

We present several measurement schemes for accessing separability criteria for continuous-variable bipartite quantum systems. Starting from moments of the bosonic mode operators, criteria suitable to witness entanglement are expressed in…

Quantum Physics · Physics 2023-08-28 Célia Griffet , Tobias Haas , Nicolas J. Cerf

We provide a recurrent construction of entanglement witnesses for a bipartite systems living in a Hilbert space corresponding to $2N$ qubits ($N$ qubits in each subsystem). Our construction provides a new method of generalization of the…

Quantum Physics · Physics 2014-05-21 Justyna P. Zwolak , Dariusz Chruściński

Local Operations enhancing the entanglement of bipartite quantum states are of great interest in quantum information processing. Subject of this paper are local selective operations acting on single copies of states. Such operations can…

Quantum Physics · Physics 2007-05-23 Juliane Strassner , Christopher Witte

If only limited control over a multiparticle quantum system is available, a viable method to characterize correlations is to perform random measurements and consider the moments of the resulting probability distribution. We present…

Quantum Physics · Physics 2021-04-23 Satoya Imai , Nikolai Wyderka , Andreas Ketterer , Otfried Gühne

In quantum information theory, the reliable and effective detection of entanglement is of paramount importance. However, given an unknown state, assessing its entanglement is a challenging task. To attack this problem, we investigate the…

Quantum Physics · Physics 2015-12-09 Jochen Szangolies , Hermann Kampermann , Dagmar Bruß

We recently showed that multipartite correlations between outcomes of random observables detect quantum entanglement in all pure and some mixed states. In this followup article we further develop this approach, derive a maximal amount of…

Quantum Physics · Physics 2016-10-11 Minh Cong Tran , Borivoje Dakic , Wieslaw Laskowski , Tomasz Paterek

We derive reliable entanglement witnesses for coarse--grained measurements on continuous variable systems. These witnesses never return a "false positive" for identification of entanglement, under any degree of coarse graining. We show…

Quantum Physics · Physics 2013-06-18 D. S. Tasca , Łukasz Rudnicki , R. M. Gomes , F. Toscano , S. P. Walborn

We introduce a general method for the experimental detection of entanglement by performing only few local measurements, assuming some prior knowledge of the density matrix. The idea is based on the minimal decomposition of witness operators…

Quantum Physics · Physics 2009-11-07 O. Guehne , P. Hyllus , D. Bruss , A. Ekert , M. Lewenstein , C. Macchiavello , A. Sanpera

This paper presents an efficient method for detecting entanglement in high-dimensional two-qudit states by mapping the Hilbert space onto the space of two qubits. This transformation enables the use of well-established two-qubit…

Quantum Physics · Physics 2026-02-25 Josef Kadlec , Artur Barasiński , Karel Lemr

In this paper we introduce a criterion for the characterization of Entanglement Witness for multipartite quantum systems. Our approach is based on the characterization of the "tangent space" to the set of pure product states.

Quantum Physics · Physics 2012-10-30 Fabio Masillo

In this paper we provide an operational method to detect multipartite entanglement in ensemble-based quantum computing. This method is based on the concept of entanglement witness. We decompose the entanglement witness for each class of…

Quantum Physics · Physics 2015-06-26 Robabeh Rahimi , Akira SaiToh , Mikio Nakahara , Masahiro Kitagawa