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Related papers: Average concurrence and entanglement swapping

200 papers

Quantum entanglement plays a pivotal role in quantum information processing. Quantifying quantum entanglement is a challenging and essential research area within the field. This manuscript explores the relationships between bipartite…

Quantum Physics · Physics 2025-04-22 Ming Li , Yaru Dong , Ruiqi Zhang , Xuena Zhu , Shuqian Shen , Lei Li , Shao-Ming Fei

In this Brief Report we show the relation between three-qubit entanglement invariants and two-qubit concurrence with the help of projective measurements. How to use these invariants to represent the entanglement property of three-qubit pure…

Quantum Physics · Physics 2009-11-13 Wen-Long Yang , Jing-Ling Chen

We study the entanglement between a certain qubit and the remaining system in rank- 2 mixed states prepared on the quantum computer. The protocol, which we propose for this purpose, is based on the relation of geometric measure of…

Quantum Physics · Physics 2021-05-24 A. R. Kuzmak , V. M. Tkachuk

Entanglement represents a pure quantum effect involving two or more particles. Spin systems are good candidates for studying this effect and its relation with other collective phenomena ruled by quantum mechanics. While the presence of…

Statistical Mechanics · Physics 2007-05-23 Andrea Fubini , Stephan Haas , Tommaso Roscilde , Valerio Tognetti , Paola Verrucchi

We investigate the monogamy relations related to the concurrence and the entanglement of formation. General monogamy inequalities given by the {\alpha}th power of concurrence and entanglement of formation are presented for N-qubit states.…

Quantum Physics · Physics 2014-09-04 Xuena Zhu , Shaoming Fei

In this paper, I will derive a measure of entanglement that coincides with the generalized concurrence for a general pure bi-and three-partite state based on wedge product. I will show that a further generalization of this idea to a general…

Quantum Physics · Physics 2017-08-23 Hoshang Heydari

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

Based on a proposed coherence measure, we show that the local coherence of a bipartite quantum pure state (coherence of its reduced density matrix) is exactly the same as the minimal average co- herence with all potential pure-state…

Quantum Physics · Physics 2014-11-04 Chang-shui Yu , He-shan Song

Bi-partite entanglement in multi-qubit systems cannot be shared freely. The rules of quantum mechanics impose bounds on how multi-qubit systems can be correlated. In this paper we utilize a concept of entangled graphs with weighted edges in…

Quantum Physics · Physics 2009-11-10 Martin Plesch , Jaroslav Novotny , Zuzana Dzurakova , Vladimir Buzek

Entanglement concurrence has been widely used for featuring entanglement in quantum experiments. As an entanglement monotone it is related to specific quantum Tsallis entropy. Our goal in this paper is to propose a new parameterized…

Quantum Physics · Physics 2021-05-26 Xue Yang , Ming-Xing Luo , Yan-Han Yang , Shao-Ming Fei

This note quantifies the continuity properties of entanglement: how much does entanglement vary if we change the entangled quantum state just a little? This question is studied for the pure state entanglement of a bipartite system and for…

Quantum Physics · Physics 2009-10-31 M. A. Nielsen

Quantum entanglement is essential to the development of quantum computation, communications, and technology. The controlled SWAP test, widely used for state comparison, can be adapted to an efficient and useful test for entanglement of a…

Quantum Physics · Physics 2022-01-12 Steph Foulds , Viv Kendon , Tim Spiller

We consider entanglement swapping with general mixed two-mode Gaussian states and calculate the optimal gains for a broad class of such states including those states most relevant in communication scenarios. We show that for this class of…

Quantum Physics · Physics 2013-05-29 Jason Hoelscher-Obermaier , Peter van Loock

In this paper, we study the multipartite entanglement properties of graph states up to seven qubits. Our analysis shows that the generalized concurrence measure is more efficient than geometric entanglement measure for measuring…

Quantum Physics · Physics 2023-07-20 Saeed Haddadi , Ahmad Akhound , Mohammad Ali Chaman Motlagh

We study the concurrence of arbitrary dimensional bipartite quantum systems. An explicit analytical lower bound of concurrence is obtained, which detects entanglement for some quantum states better than some well-known separability…

Quantum Physics · Physics 2011-04-07 Xiao-Sheng Li , Xiu-Hong Gao , Shao-Ming Fei

We study the concurrence of arbitrary dimensional bipartite quantum systems. By using a positive but not completely positive map, we present an analytical lower bound of concurrence. Detailed examples are used to show that our bound can…

Quantum Physics · Physics 2014-01-09 Hui-hui Qin , Shao-Ming Fei

We study the concurrence of arbitrary dimensional multipartite quantum systems. An explicit analytical lower bound of concurrence for four-partite mixed states is obtained in terms of the concurrences of tripartite mixed states. Detailed…

Quantum Physics · Physics 2017-10-31 Wei Chen , Xue-Na Zhu , Shao-Min Fei , Zhu-Jun Zheng

We focus on the general theory of entanglement swapping, including entanglement swapping of pure and mixed states. We also study the theory of entangled swapping chains, which can be regarded as an application of entangled swapping. For…

Quantum Physics · Physics 2025-12-09 Zhaoxu Ji , Huanguo Zhang

The concept of local concurrence is used to quantify the entanglement between a single qubit and the remainder of a multi-qubit system. For the ground state of the BCS model in the thermodynamic limit the set of local concurrences…

Quantum Physics · Physics 2009-11-10 Clare Dunning , Jon Links , Huan-Qiang Zhou

We investigate a two-qubit system to understand the relationship between concurrence and mutual information, where the former determines the amount of quantum entanglement, whereas the latter is its classical residue after performing local…

Quantum Physics · Physics 2022-10-05 Yong Kwon , Seung Ki Baek , Jaegon Um