Deterministic entanglement of assistance in quantum networks

2006 ◽  
Vol 84 (6-7) ◽  
pp. 639-644
Author(s):  
B C Sanders ◽  
G Gour ◽  
D A Meyer

We present a powerful theorem for tripartite remote entanglement distribution protocols, which provides an operational interpretation of concurrence as a type of entanglement capacity, and we establish that concurrence of assistance, which we show is an entanglement monotone, identifies capabilities of and limitations to producing pure bipartite entangled states from pure tripartite entangled states. In addition, we show that, if concurrence of assistance for the pure tripartite state is at least as large as the concurrence of the desired pure bipartite state, then the former may be transformed to the latter via local operations and classical communication, and we calculate the maximum probability for this transformation when this condition is not met.PACS Nos.: 03.67.Mn, 03.67.Hk, 03.65.Ud

Quantum ◽  
2020 ◽  
Vol 4 ◽  
pp. 348
Author(s):  
Axel Dahlberg ◽  
Jonas Helsen ◽  
Stephanie Wehner

Critical to the construction of large scale quantum networks, i.e. a quantum internet, is the development of fast algorithms for managing entanglement present in the network. One fundamental building block for a quantum internet is the distribution of Bell pairs between distant nodes in the network. Here we focus on the problem of transforming multipartite entangled states into the tensor product of bipartite Bell pairs between specific nodes using only a certain class of local operations and classical communication. In particular we study the problem of deciding whether a given graph state, and in general a stabilizer state, can be transformed into a set of Bell pairs on specific vertices using only single-qubit Clifford operations, single-qubit Pauli measurements and classical communication. We prove that this problem is NP-Complete.


Author(s):  
Vladimir Gavrilov ◽  
Tatyana Antipova ◽  
Yan Vlasov ◽  
Sergey Ardatov ◽  
Anastasia Ardatova

In their previous works , leading their history since 1988, the authors of this article have repeatedly conceptually shown and experimentally verified the results of research on the teleportation of information between macro objects. Early author's works were performed during the existence of the Russian Federation – as a country called the Union of Soviet Socialist Republics (USSR). Some of which were marked "Top Secret" - links further down the text. Since they were performed under the supervision of the relevant special services and further "Department of external relations of the Russian Academy of Sciences". The authors used numerous examples to demonstrate the possibility of teleportation of information in macro-systems, including ecosystem, biogeocenotic levels, and then tissue and organism levels. Successful experimental verifications occurred only in cases when all the principles and rules laid down in the theory of quantum information, applied to biological objects, were correctly combined. Namely, the preparation of cascades of entangled States was performed both on the mental and somatic levels. In full accordance with the principle of complementarity and taking into account the fact that the observer and the observed are actively connected by the sum of similarities. In addition, the role of the classical communication channel in this process was performed by carrier electromagnetic fields modulated by a useful signal. This signal represented a cast of the simulated experimental process. An example of a real COVID-19 pandemic is the verification of author's works in nature on a biogeocenotic scale. And certainly with anthropogenic – so to speak-participation.


2015 ◽  
Vol 15 (13&14) ◽  
pp. 1223-1232
Author(s):  
Chengjun Wu ◽  
Bin Luo ◽  
Hong Guo

When Alice and Bob share two pairs of quantum correlated states, Alice can remotely prepare quantum entanglement and quantum discord in Bob’s side by measuring the parts in her side and telling Bob the measurement results by classical communication. For remote entanglement preparation, entanglement is necessary . We find that for some shared resources having the same amount of entanglement, when Bell measurement is used, the entanglement remotely prepared can be different, and more discord in the resources actually decreases the entanglement prepared. We also find that for some resources with more entanglement, the entanglement remotely prepared may be less. Therefore, we conclude that entanglement is a necessary resource but may not be the only resource responsible for the entanglement remotely prepared, and discord does not likely to assist this process. Also, for the preparation of discord, we find that some states with no entanglement could outperform entangled states.


Author(s):  
S. K. Joshi ◽  
Z. Huang ◽  
A Fletcher ◽  
N Solomons ◽  
I. V. Puthoor ◽  
...  

2014 ◽  
Vol 12 (03) ◽  
pp. 1450011 ◽  
Author(s):  
Pengfei Xing ◽  
Yimin Liu ◽  
Chuanmei Xie ◽  
Xiansong Liu ◽  
Zhanjun Zhang

Two three-party schemes are put forward for sharing quantum operations on a remote qutrit with local operation and classical communication as well as shared entanglements. The first scheme uses a two-qutrit and three-qutrit non-maximally entangled states as quantum channels, while the second replaces the three-qutrit non-maximally entangled state with a two-qutrit. Both schemes are treated and compared from the four aspects of quantum and classical resource consumption, necessary-operation complexity, success probability and efficiency. It is found that the latter is overall more optimal than the former as far as a restricted set of operations is concerned. In addition, comparisons of both schemes with other four relevant ones are also made to show their two features, including degree generalization and channel-state generalization. Furthermore, some concrete discussions on both schemes are made to expose their important features of security, symmetry and experimental feasibility. Particularly, it is revealed that the success probabilities and intrinsic efficiencies in both schemes are completely determined by the shared entanglement.


Author(s):  
Yuan Lee ◽  
Eric Bersin ◽  
Axel Dahlberg ◽  
Stephanie Wehner ◽  
Dirk Englund

Science ◽  
2007 ◽  
Vol 316 (5829) ◽  
pp. 1316-1320 ◽  
Author(s):  
C.-W. Chou ◽  
J. Laurat ◽  
H. Deng ◽  
K. S. Choi ◽  
H. de Riedmatten ◽  
...  

2008 ◽  
Vol 06 (02) ◽  
pp. 237-253 ◽  
Author(s):  
J. BATLE ◽  
M. CASAS

This work reviews and extends recent results concerning the distribution of entanglement, as well as nonlocality (in terms of inequality violations) in tripartite qubit systems. With recourse to a Monte Carlo generation of pure and mixed states of three-qubits, we explore several features related to the distribution of entanglement (expressed in the form of different measures of multiqubit entanglement based upon bipartitions). Also, special interest is paid to maximally entangled states (such as the GHZ for three-qubits) and W states. This study also sheds some light on the interesting relation existing between some entanglement measures and perfect state discrimination in LOCC measurements relevant to cryptographic protocols. We round off the results by studying the distribution of entanglement between Alice and Bob in a modified teleportation protocol toy model over three-qubit states.


Optica ◽  
2021 ◽  
Author(s):  
Navin Lingaraju ◽  
Hsuan-Hao Lu ◽  
Suparna Seshadri ◽  
Daniel Leaird ◽  
Andrew Weiner ◽  
...  

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