English
Related papers

Related papers: Entanglement of assistance in three-qubit systems

200 papers

Entanglement distribution is essential for unlocking the potential of distributed quantum information processing. We consider an $N$-partite network where entanglement is distributed via a central source over lossy channels, and network…

Quantum Physics · Physics 2025-04-01 Leonardo Oleynik , Junaid ur Rehman , Seid Koudia , Symeon Chatzinotas

I explore the entanglement dynamics of a three qubit system in an initial X-state undergoing decoherence including the possible exhibition of entanglement sudden death (ESD). To quantify entanglement I utilize negativity measures and make…

Quantum Physics · Physics 2015-05-18 Yaakov S. Weinstein

We consider the mixed three-qubit bound entangled state defined as the normalized projector on the subspace that is complementary to an Unextendible Product Basis [C. H. Bennett et. al., Phys. Rev. Lett. 82, 5385 (1999)]. Using the fact…

Quantum Physics · Physics 2010-07-28 Cyril Branciard , Huangjun Zhu , Lin Chen , Valerio Scarani

The relation between the violation of the Bell-CHSH inequalities and entanglement properties of quantum states is not clear so one may consider the mixedness of the system to understand the entanglement properties better than the Bell-CHSH…

Quantum Physics · Physics 2009-06-11 Satyabrata Adhikari

We present optimal measuring strategies for the estimation of the entanglement of unknown two-qubit pure states and of the degree of mixing of unknown single-qubit mixed states, of which N identical copies are available. The most general…

Quantum Physics · Physics 2009-10-31 A. Acin , R. Tarrach , G. Vidal

Quantum entanglement is at the heart of many tasks in quantum information. Apart from simple cases (low dimensions, few particles, pure states), however, the mathematical structure of entanglement is not yet fully understood. This tutorial…

Quantum Physics · Physics 2015-06-26 Dagmar Bruss

Entanglement has been proposed as a means to improve the sensitivity of sensing weak signals. While the degree of this quantum advantage is well understood in noiseless settings, the situation is more complex under realistic conditions,…

Quantum Physics · Physics 2026-05-07 Noah Kaufmann , Kasper H. Nielsen , Eva M. González-Ruiz , Anders S. Sørensen

Despite their importance in quantum theory, joint quantum measurements remain poorly understood. An intriguing conceptual and practical question is whether joint quantum measurements on separated systems can be performed without bringing…

Quantum Physics · Physics 2025-12-23 Jef Pauwels , Alejandro Pozas-Kerstjens , Flavio Del Santo , Nicolas Gisin

Our investigation aims to study the specific role played by entanglement in the quantum computation process, by elaborating an entangled spin model developed within the 'hidden measurement approach' to quantum mechanics. We show that an…

Quantum Physics · Physics 2007-05-23 Diederik Aerts , Ellie D'Hondt , Bart D'Hooghe

Entanglement appears under two different forms in quantum theory, namely as a property of states of joint systems and as a property of measurement eigenstates in joint measurements. By combining these two aspects of entanglement, it is…

A pair of two level atoms A1A2, prepared either in a separable state or in an entangled state, interacts with a single mode of two mode squeezed cavity field while a third atomic qubit B interacts with the second mode of the squeezed field…

Quantum Physics · Physics 2013-05-03 Paulo Jose dos Reis , S. Shelly Sharma , N. K. Sharma

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

We address some of the most commonly raised questions about entanglement, especially with regard to so-called occupation number entanglement. To answer unambiguously whether entanglement can exist in a one-atom delocalized state, we propose…

Quantum Physics · Physics 2007-05-23 M. O. Terra Cunha , J. A. Dunningham , V. Vedral

Entanglement assistance is known to reduce the quantum communication complexity of evaluating functions with distributed inputs. But does the type of entanglement matter, or are EPR pairs always sufficient? This is a natural question…

Quantum Physics · Physics 2019-07-17 Matthew Coudron , Aram W. Harrow

We study the entanglement evolution of the set of Bell diagonal states for a two-qubit system coupled to two independent vacuum noise sources. This set can be represented geometrically as the set of points inside a tetrahedron in a…

Quantum Physics · Physics 2015-01-09 Ramsés Sánchez , Esteban Isasi , Douglas Mundarain

Detection of entanglement in quantum networks consisting of many parties is one of the important steps towards building quantum communication and computation networks. We consider a scenario where the measurement devices used for this…

Quantum Physics · Physics 2017-05-03 Ivan Šupić , Paul Skrzypczyk , Daniel Cavalcanti

The uncertainty principle, which bounds the uncertainties involved in obtaining precise outcomes for two complementary variables defining a quantum particle, is a crucial aspect in quantum mechanics. Recently, the uncertainty principle in…

Quantum Physics · Physics 2012-04-24 Chuan-Feng Li , Jin-Shi Xu , Xiao-Ye Xu , Ke Li , Guang-Can Guo

We investigate bipartite and tripartite entanglement in an open quantum system, specifically three qubits, all of which are damped, and one of which is driven. We adapt a systematic approach in calculating the entanglement of various…

Quantum Physics · Physics 2018-07-18 William Konyk , Ethan Stanifer , Habtom Woldekristos , James Clemens , Perry Rice

Quantum entanglement between several particles is essential for applications like quantum metrology or quantum cryptography, but it is also central for foundational phenomena like quantum non-locality. This leads to the problem of…

Quantum Physics · Physics 2025-10-10 Lisa T. Weinbrenner , Otfried Gühne

One of the most fascinating aspects of quantum networks is their capability to distribute entanglement as a nonlocal communication resource. In a first step, this requires network-ready devices that can generate and store entangled states.…