English
Related papers

Related papers: Entanglement detection via condition of quantum co…

200 papers

From a practical perspective it is advantageous to develop methods that verify entanglement in quantum states with as few measurements as possible. In this paper we investigate the minimal number of mutually unbiased bases (MUBs) needed to…

Quantum Physics · Physics 2023-03-14 Joonwoo Bae , Anindita Bera , Dariusz Chruściński , Beatrix C. Hiesmayr , Daniel McNulty

We propose a entanglement measure for pure $M \otimes N$ bipartite quantum states. We obtain the measure by generalizing the equivalent measure for a $2 \otimes 2$ system, via a $2 \otimes 3$ system, to the general bipartite case. The…

Quantum Physics · Physics 2016-08-16 Hoshang Heydari , Gunnar Björk

We present a class of linear correlation witnesses that detects bound entanglement within a three-party prepare-and-measure scenario with four-dimensional quantum messages. We relate the detection power of our witnesses for two-ququart…

Quantum Physics · Physics 2025-10-31 István Márton , Erika Bene , Tamás Vértesi

We present a unified framework for multipartite entanglement characterization based on the conditional gradient (CG) method, incorporating both fast heuristic detection and rigorous witness construction with numerical error control. Our…

Quantum Physics · Physics 2025-08-04 Ye-Chao Liu , Jannis Halbey , Sebastian Pokutta , Sébastien Designolle

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

We consider the problem of entanglement detection in the presence of faulty, potentially malicious detectors. A common - and, as of yet, the only - approach to this problem is to perform a Bell test in order to identify nonlocality of the…

Quantum Physics · Physics 2024-09-20 Giuseppe Viola , Nikolai Miklin , Mariami Gachechiladze , Marcin Pawłowski

The efficient witnessing and certification of entanglement is necessitated by its ubiquitous use in various aspects of quantum technologies. In the case of continuous-variable bipartite systems, the Shchukin--Vogel hierarchy gives necessary…

Quantum Physics · Physics 2025-09-09 Elena Callus , Martin Gärttner , Tobias Haas

We study local-realistic inequalities, Bell-type inequalities, for bipartite pure states of finite dimensional quantum systems -- qudits. There are a number of proposed Bell-type inequalities for such systems. Our interest is in relating…

Quantum Physics · Physics 2017-04-19 Chandan Datta , Pankaj Agrawal , Sujit K. Choudhary

Design of detection strategies for multipartite entanglement stands as a central importance on our understanding of fundamental quantum mechanics and has had substantial impact on quantum information applications. However, accurate and…

Quantum Physics · Physics 2023-05-24 Xin-Yu Xu , Qing Zhou , Shuai Zhao , Shu-Ming Hu , Li Li , Nai-Le Liu , Kai Chen

We introduce a family of entanglement witnesses for continuous variable systems, which rely on the sole assumption that their dynamics is that of coupled harmonic oscillators at the time of the test. Entanglement is inferred from the…

Quantum Physics · Physics 2024-07-31 Pooja Jayachandran , Lin Htoo Zaw , Valerio Scarani

Detecting entanglement in many-body quantum systems is crucial but challenging, typically requiring multiple measurements. Here, we establish the class of states where measuring connected correlations in just $\textit{one}$ basis is…

Quantum Physics · Physics 2024-04-05 Roopayan Ghosh , Sougato Bose

We derive tight quadratic inequalities for all kinds of hybrid separable-inseparable $n$-particle density operators on an arbitrary dimensional space. This methodology enables us to truly derive a tight quadratic inequality as tests for…

Quantum Physics · Physics 2009-11-07 Koji Nagata , Masato Koashi , Nobuyuki Imoto

How to detect quantum correlations in bi-partite scenarios using a split many-body system and collective measurements on each party? We address this question by deriving entanglement witnesses using either only first or first and second…

Quantum Physics · Physics 2017-06-07 Enky Oudot , Jean-Daniel Bancal , Roman Schmied , Philipp Treutlein , Nicolas Sangouard

We present a broad class of states which are diagonal in the basis of N-qubit GHZ states such that non-positivity under the partial transpose operation is necessary and sufficient for the presence of entanglement. This class includes many…

Quantum Physics · Physics 2011-02-23 Alastair Kay

We introduce two families of criteria for detecting and quantifying the entanglement of a bipartite quantum state of arbitrary local dimension. The first is based on measurements in mutually unbiased bases and the second is based on…

Quantum Physics · Physics 2023-11-08 Simon Morelli , Marcus Huber , Armin Tavakoli

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

A sufficient condition for entanglement in two-mode continuous systems is constructed based on interference visibility and the uncertainty of the total particle number. The observables to be measured (particle numbers and particle number…

Quantum Physics · Physics 2007-05-23 Geza Toth , Christoph Simon , Juan Ignacio Cirac

The unambiguous detection and quantification of entanglement is a hot topic of scientific research, though it is limited to low dimensions or specific classes of states. Here we identify an additional class of quantum states, for which…

Quantum Physics · Physics 2014-12-03 Marco Roncaglia , Arianna Montorsi , Marco Genovese

We introduce a new entanglement measure based on optimal entanglement witness. First of all, we show that the entanglement measure satisfies some necessary properties, including zero entanglements for all separable states, convexity,…

Quantum Physics · Physics 2024-02-20 Nan Yang , Jiaji Wu , Xianyun Dong , Longyu Xiao , Jing Wang , Ming Li

In recent years considerable progress has been made towards developing a general theory of quantum entanglement. In particular, criteria to decide whether a given quantum state is entangled are of high theoretical and practical interest.…

Quantum Physics · Physics 2025-01-27 Shruti Aggarwal