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Related papers: Coherence Concurrence for X States

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A simple relation is introduced for concurrence to describe how much the entanglement of bipartite system is at least left if either (or both) subsystem undergoes an arbitrary physical process. This provides a lower bound for concurrence of…

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

We study the role of average concurrence in entanglement swapping in quantum networks. We begin with qubit pure states, and there is a very simple rule governing the propagation of average concurrence in multiple swaps. We look at examples…

Quantum Physics · Physics 2021-09-01 János A. Bergou , Dov Fields , Mark Hillery , Siddhartha Santra , Vladimir S. Malinovsky

We discuss a kind of generalized concurrence for a class of high dimensional quantum pure states such that the entanglement of formation is a monotonically increasing convex function of the generalized concurrence. An analytical expression…

Quantum Physics · Physics 2009-11-10 Shao-Ming Fei , Zhi-Xi Wang , Hui Zhao

We investigate the discrimination of pure-mixed (quantum filtering) and mixed-mixed states and compare their optimal success probability with the one for discriminating other pairs of pure states superposed by the vectors included in the…

Quantum Physics · Physics 2021-12-24 Jin-Hua Zhang , Fu-Lin Zhang , Zhi-Xi Wang , Hui Yang , Shao-Ming Fei

Quantum entanglement is a crucial resource in quantum information processing, advancing quantum technologies. The greater the uncertainty in subsystems' pure states, the stronger the quantum entanglement between them. From the dual form of…

Quantum Physics · Physics 2026-01-01 Dong-Ping Xuan , Zhong-Xi Shen , Wen Zhou , Zhi-Xi Wang , Shao-Ming Fei

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

Quantum coherence and entanglement orignate from the superposition principle. We derive a rigorous relation between the ${l_1}$-norm of coherence and concurrence, in that we show that the former is always greater than the latter. This…

Quantum Physics · Physics 2022-05-24 Pranav Kairon , Mukhtiyar Singh , Satyabrata Adhikari

In this paper we use the \textit{concurrence vector}, as a measure of entanglement, and investigate lower and upper bounds on the concurrence of a superposition of bipartite states as a function of the concurrence of the superposed states.…

Quantum Physics · Physics 2016-04-19 Seyed Javad Akhtarshenas

Quantifying quantum coherence is a key task in the resource theory of coherence. Here we establish a good coherence monotone in terms of a state conversion process, which automatically endows the coherence monotone with an operational…

Quantum Physics · Physics 2020-07-01 Deng-hui Yu , Li-qiang Zhang , Chang-shui Yu

The concept of concurrence is researched to characterize the dynamical behavior of the bipartite systems. The quantum kicked top model has great significance in the qubit systems and the chaotic properties of the entanglement. The…

Quantum Physics · Physics 2024-01-01 A. Fulop

Despite the successful experimental generation and verification of genuine multipartite entanglement, several existing entanglement measures remain insufficient to reliably capture its presence. In this study, we overcome this challenge by…

Quantum Physics · Physics 2025-10-20 Shruti Aggarwal

We establish a quantitative relation between local spin polarization and quantum entanglement in two-qubit systems by deriving an upper bound on the concurrence at fixed local polarizations, showing that increasing polarization constrains…

High Energy Physics - Phenomenology · Physics 2026-05-25 Yu-Xuan Liu , Wei Qi , Luo-Ting He , Bo-Wen Xiao

Quantum measurements necessarily disturb the state of physical system. Once we perform a complete measurement, the system undergoes decoherence and loses its coherence. If there is no disturbance, the state retains all of its coherence. It…

Quantum Physics · Physics 2018-10-10 Gautam Sharma , Arun Kumar Pati

Quantifying genuine entanglement is a key task in quantum information theory. We study the quantification of genuine multipartite entanglement for four-qubit systems. Based on the concurrence of nine different classes of four-qubit states,…

Quantum Physics · Physics 2023-07-19 Meng-Li Guo , Zhi-Xiang Jin , Bo Li , Shao-Ming Fei

We establish the profound equivalence between measures of genuine multipartite entanglement(GME) and their corresponding coherence measures. Initially we construct two distinct classes of measures for genuine multipartite entanglement…

Quantum Physics · Physics 2024-11-19 Zong Wang , Zhihua Guo , Zhihua Chen , Ming Li , Zihang Zhou , Chengjie Zhang , Shao-Ming Fei , Zhihao Ma

Quantum coherence and entanglement are two key features in quantum mechanics and play important roles in quantum information processing and quantum computation. We provide a general triangle-like inequality satisfied by the $l_1$-norm…

Quantum Physics · Physics 2018-11-21 Zhi-Xiang Jin , Xianqing Li-Jost , Shao-Ming Fei

We prove some new properties of fidelity (transition probability) and concurrence, the latter defined by straightforward extension of Wootters notation. Choose a conjugation and consider the dependence of fidelity or of concurrence on…

Quantum Physics · Physics 2009-10-31 Armin Uhlmann

We establish a relation between concurrence and entanglement witnesses. In particular, we construct entanglement witnesses for three-qubit W and GHZ states in terms of concurrence and different set of operators that generate it. We also…

Quantum Physics · Physics 2008-06-05 Hoshang Heydari

We propose generalizations of concurrence for multi-partite quantum systems that can distinguish qualitatively distinct quantum correlations. All introduced quantities can be evaluated efficiently for arbitrary mixed sates.

Quantum Physics · Physics 2009-11-10 Florian Mintert , Marek Kus , Andreas Buchleitner

Quantification of quantum entanglement plays a crucial role in the study of quantum information tasks. We present analytical lower bounds for both concurrence and 2-concurrence based on the correlation matrices of bipartite quantum states.…

Quantum Physics · Physics 2025-03-21 Zhi-Bo Chen , Shao-Ming Fei