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Related papers: Coherence Concurrence for X States

200 papers

We investigate the decay of entanglement, due to decoherence, of multi-qubit systems that are initially prepared in highly (in some cases maximally) entangled states. We assume that during the decoherence processes each qubit of the system…

Quantum Physics · Physics 2009-11-13 A. Borras , A. P. Majtey , A. R. Plastino , M. Casas , A. Plastino

Experimental determination of entanglement is important not only to characterize the state and use it in quantum information, but also in understanding complicated phenomena such as phase transitions. In this paper we show that in many…

Quantum Physics · Physics 2016-01-20 Gaurav Chaudhary , V. Ravishankar

We study the dynamics of multipartite entanglement under the influence of decoherence. A suitable generalization of concurrence reveals distinct scaling of the entanglement decay rate of GHZ and W states, for various environments.

Quantum Physics · Physics 2009-11-10 André R. R. Carvalho , Florian Mintert , Andreas Buchleitner

As an analogy of fully entangled fraction in the framework of entanglement theory, we have introduced the notion of quantum coherence fraction $C_{\mathcal{F}}$, which quantifies the closeness between a given state and the set of maximally…

Quantum Physics · Physics 2019-09-25 Yao Yao , Dong Li , C. P. Sun

We propose a general scheme to measure the concurrence of an arbitrary two-qubit pure state in atomic systems. The protocol is based on one- and two-qubit operations acting on two available copies of the bipartite system, and followed by a…

Quantum Physics · Physics 2015-06-26 G. Romero , C. E. Lopez , F. Lastra , E. Solano , J. C. Retamal

Quantum resources play crucial roles for displaying superiority in many quantum communication and computation tasks. To reveal the intrinsic relations hidden in these quantum resources, many efforts have been made in recent years. In this…

Quantum Physics · Physics 2019-03-27 Wen-Yang Sun , Dong Wang , Bao-Long Fang , Zhi-Yong Ding , Huan Yang , Fei Ming , Liu Ye

Quantum coherence, incompatibility, and quantum correlations are fundamental features of quantum physics. A unified view of those features is crucial for revealing quantitatively their intrinsic connections. We define the relative quantum…

Quantum Physics · Physics 2017-05-30 Ming-Liang Hu , Heng Fan

Experimentally quantifying entanglement and coherence are extremely important for quantum resource theory. However, because the quantum state tomography requires exponentially growing measurements with the number of qubits, it is hard to…

Quantum Physics · Physics 2020-05-13 Yue Dai , Yuli Dong , Zhenyu Xu , Wenlong You , Chengjie Zhang , Otfried Gühne

Self-interactions and interaction with the environment tend to push quantum systems toward states of maximal entanglement. This is a definition of decoherence. We argue that these maximally entangled states fall into the well-defined…

Quantum Physics · Physics 2022-10-17 Roman V. Buniy , Robert P. Feger , Thomas W. Kephart

The quantum entanglement measure of concurrence is shown to be directly calculable from a Tomita- Takesaki modular operator framework constructed from the local von Neumann algebras of observables for two quantum systems. Specifically, the…

Quantum Physics · Physics 2024-09-18 Rupak Chatterjee

The $k$-ME concurrence as a measure of multipartite entanglement (ME) unambiguously detects all $k$-nonseparable states in arbitrary dimensions, and satisfies many important properties of an entanglement measure. Negativity is a simple…

Quantum Physics · Physics 2020-02-28 Limei Zhang , Ting Gao , Fengli Yan

The quantumness of a generic state is the resource of many applications in quantum information theory and it is interesting to survey the measures which are able to detect its trace in the properties of the state. In this work we study the…

Quantum Physics · Physics 2016-04-26 Javad Behdani , Seyed Javad Akhtarshenas , Mohsen Sarbishaei

We investigate the correlation properties of separable two qubit states with maximally mixed marginals. These states are divided to two sets with the same geometric quantum correlation. However a closer scrutiny of these states reveals a…

Quantum Physics · Physics 2015-01-14 Azam Mani , Vahid Karimipour , Laleh Memarzadeh

We refine the notion of concurrence in this paper by a redefinition of the concept. The new definition is simpler, computationally straight forward, and allows the concurrence to be directly read off from the state. It has all the positive…

Quantum Physics · Physics 2007-05-23 D. D. Bhaktavatsala Rao , V. Ravishankar

Concurrence, introduced by Hill and Wootters [Phys. Rev. Lett. 78, 5022 (1997)], provides an important measure of entanglement for a general pair of qubits that is faithful: strictly positive for entangled states and vanishing for all…

Quantum Physics · Physics 2017-03-29 Vineeth S. Bhaskara , Prasanta K. Panigrahi

In this work we study the so-called quantitative complementarity quantities. We focus in the following physical situation: two qubits ($q_A$ and $q_B$) are initially in a maximally entangled state. One of them ($q_B$) interacts with a…

Quantum Physics · Physics 2017-01-26 Leonardo A. M. Souza , Nadja K. Bernardes , Romeu Rossi

Quantum coherence plays an important role in quantum resource theory, which is strongly related with entanglement. Similar to the entanglement evolution equation, we find the coherence evolution equation of quantum states through fully and…

Quantum Physics · Physics 2024-02-26 Xinzhi Zhao , Jianwei Shao , Yi Zheng , Wen-Zhao Zhang , Chengjie Zhang

Entanglement of any pure state of an N times N bi-partite quantum system may be characterized by the vector of coefficients arising by its Schmidt decomposition. We analyze various measures of entanglement derived from the generalized…

Quantum Physics · Physics 2009-11-07 Karol Zyczkowski , Ingemar Bengtsson

We plot the geometry of several distance-based quantifiers of coherence for Bell-diagonal states. We find that along with both $l_{1}$ norm and relative entropy of coherence changes continuously from zero to one, their surfaces move from…

Quantum Physics · Physics 2017-03-08 Yao-Kun Wang , Lian-He Shao , Yu-Ran Zhang

We investigate the distributions of quantum coherence characterized by superadditivity relations in multipartite quantum systems. General superadditivity inequalities based on the $\alpha$th ($\alpha\geqslant 1$) power of $l_1$ norm of…

Quantum Physics · Physics 2021-05-11 Xianfei Qi , Ting Gao , Fengli Yan