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Too much noise kills entanglement. This is the main problem in its production and transmission. We use a handy approach to indicate noise resistance of entanglement of a bi-partite system described by $d\times d$ Hilbert space. Our analysis…

Quantum Physics · Physics 2016-10-10 Arijit Dutta , Junghee Ryu , Wieslaw Laskowski , Marek Zukowski

A significant problem for current quantum computers is noise. While there are many distinct noise channels, the depolarizing noise model often appropriately describes average noise for large circuits involving many qubits and gates. We…

The verification of quantum entanglement under the influence of realistic noise and decoherence is crucial for the development of quantum technologies. Unfortunately, a full entanglement characterization is generally not possible with most…

Quantum Physics · Physics 2017-10-18 P. Thomas , M. Bohmann , W. Vogel

We present a new approach to the analysis of entanglement in smooth bipartite continuous-variable states. One or both parties perform projective filterings via preliminary measurements to determine whether the system is located in some…

Quantum Physics · Physics 2009-11-13 H. -C. Lin , A. J. Fisher

Quantum entanglement is an indispensable resource for many significant quantum information processing tasks. Thus, distilling more entanglement from less entangled resource is a task of practical significance and has been investigated for…

Quantum Physics · Physics 2024-01-18 Zhaofeng Su , Nina Sukhodoeva

Entanglement boosts performance limits in sensing and communication, and surprisingly the advantage over classical protocols can be even larger in presence of entanglement-breaking noise. However, to maximally fulfill such advantages…

Quantum Physics · Physics 2023-04-24 Haowei Shi , Bingzhi Zhang , Quntao Zhuang

Quantum metrology exploits entangled states of particles to improve sensing precision beyond the limit achievable with uncorrelated particles. All previous methods required detection noise levels below this standard quantum limit to realize…

Quantum Physics · Physics 2020-12-09 O. Hosten , R. Krishnakumar , N. J. Engelsen , M. A. Kasevich

Characterizing entanglement in all but the simplest case of a two qubit pure state is a hard problem, even understanding the relevant experimental quantities that are related to entanglement is difficult. It may not be necessary, however,…

Quantum Physics · Physics 2015-06-26 J. Grondalski , D. M. Etlinger , D. F. V. James

Detecting entanglement in multipartite quantum states is an inherently probabilistic process, typically with a few measured samples. The level of confidence in entanglement detection quantifies the scheme's validity via the probability that…

Any Bell test consists of a sequence of measurements on a quantum state in space-like separated regions. Thus, a state is better than others for a Bell test when, for the optimal measurements and the same number of trials, the probability…

Quantum Physics · Physics 2009-11-11 Antonio Acin , Richard Gill , Nicolas Gisin

We investigate entanglement distribution in pure-state quantum networks. We consider the case when non-maximally entangled two-qubit pure states are shared by neighboring nodes of the network. For a given pair of nodes, we investigate how…

Quantum Physics · Physics 2009-01-19 S. Perseguers , J. Wehr , A. Acin , M. Lewenstein , J. I. Cirac

Genuine entanglement is the strongest form of multipartite entanglement. Genuinely entangled pure states contain entanglement in every bipartition and as such can be regarded as a valuable resource in the protocols of quantum information…

Quantum Physics · Physics 2021-12-07 K. V. Antipin

In this paper, we propose a method to probe entanglement in a theoretically inaccessible quantum system with either a discrete or continuous basis. Our approach leverages insights into the entanglement distribution within a four-partite…

Quantum Physics · Physics 2025-07-10 Pablo C. López Vázquez , Luis M. Piñuelas , Gustavo Montes

We consider properties of states of many qubits, which arise after sending certain entangled states via various noisy channels (white noise, coloured noise, local depolarization, dephasing and amplitude damping). Entanglement of these…

Quantum Physics · Physics 2015-05-13 Wieslaw Laskowski , Tomasz Paterek , Caslav Brukner , Marek Zukowski

We consider explicitly two examples of d-dimensional quantum channels with correlated noise and show that, in agreement with previous results on Pauli qubit channels, there are situations where maximally entangled input states achieve…

Quantum Physics · Physics 2007-05-23 E. Karpov , D. Daems , N. J. Cerf

A model of quantum noisy channel with input encoding by a classical random vector is described. An equation of optimality is derived to determine a complete set of wave functions describing quantum decodings based on quasi-measurements…

Quantum Physics · Physics 2007-05-23 V. P. Belavkin , R. L. Stratonovich

Shared entanglement can significantly amplify classical correlations between systems interacting over a limited quantum channel. A natural avenue is to use entanglement of the same dimension as the channel because this allows for unitary…

Quantum networks rely on the efficient distribution of entanglement to enable long-distance quantum communication and information processing. A key challenge in these networks is the design of routing protocols capable of maintaining high…

Networking and Internet Architecture · Computer Science 2026-05-25 Javier Vecino Peñas , Ana Fernández-Vilas , Rebeca P. Díaz-Redondo , Sergio Gándara Gándara , Manuel Fernández-Veiga

Despite multipartite entanglement being a global property of a quantum state, a number of recent works have made it clear that it can be quantified using only local measurements. This is appealing because local measurements are the easiest…

Quantum Physics · Physics 2024-09-05 Luke Coffman , Akshay Seshadri , Graeme Smith , Jacob L. Beckey

It is well known that entanglement can benefit quantum information processing tasks. Quantum illumination, when first proposed, is surprising as entanglement's benefit survives entanglement-breaking noise. Since then, many efforts have been…

Quantum Physics · Physics 2021-06-16 Quntao Zhuang