scholarly journals Entanglement distribution in pure-state quantum networks

2008 ◽  
Vol 77 (2) ◽  
Author(s):  
Sébastien Perseguers ◽  
J. Ignacio Cirac ◽  
Antonio Acín ◽  
Maciej Lewenstein ◽  
Jan Wehr
Keyword(s):  
Pure State ◽  
Quantum Networks ◽  
Entanglement Distribution

The computational power of the W and GHZ states

2006 ◽  
Vol 6 (2) ◽  
pp. 173-183
Author(s):  
E. D'Hondt ◽  
P. Panangaden
Keyword(s):  
Pure State ◽  
Lie Symmetry ◽  
Leader Election ◽  
Ghz State ◽  
W State ◽  
Computational Power ◽  
Post Processing ◽  
Distributed Consensus ◽  
Quantum Networks ◽  
Impossibility Results

It is well understood that the use of quantum entanglement significantly enhances the computational power of systems. Much of the attention has focused on Bell states and their multipartite generalizations. However, in the multipartite case it is known that there are several inequivalent classes of states, such as those represented by the W-state and the GHZ-state. Our main contribution is a demonstration of the special computational power of these states in the context of paradigmatic problems from classical distributed computing. Concretely, we show that the W-state is the only pure state that can be used to exactly solve the problem of leader election in anonymous quantum networks. Similarly we show that the GHZ-state is the only one that can be used to solve the problem of distributed consensus when no classical post-processing is considered. These results generalize to a family of W- and GHZ-like states. At the heart of the proofs of these impossibility results lie symmetry arguments.

Hybrid Quantum Networks for High-Fidelity Entanglement Distribution

2020 ◽  
Author(s):  
Yuan Lee ◽  
Eric Bersin ◽  
Axel Dahlberg ◽  
Stephanie Wehner ◽  
Dirk Englund
Keyword(s):  
High Fidelity ◽  
Quantum Networks ◽  
Entanglement Distribution

scholarly journals Functional Quantum Nodes for Entanglement Distribution over Scalable Quantum Networks

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

scholarly journals Adaptive bandwidth management for entanglement distribution in quantum networks

Optica ◽  
2021 ◽  
Author(s):  
Navin Lingaraju ◽  
Hsuan-Hao Lu ◽  
Suparna Seshadri ◽  
Daniel Leaird ◽  
Andrew Weiner ◽  
...  
Keyword(s):  
Bandwidth Management ◽  
Quantum Networks ◽  
Entanglement Distribution ◽  
Adaptive Bandwidth

scholarly journals Policies for elementary links in a quantum network

Quantum ◽  
2021 ◽  
Vol 5 ◽  
pp. 537
Author(s):  
Sumeet Khatri
Keyword(s):  
Decision Process ◽  
Success Probability ◽  
Coherence Time ◽  
Decision Processes ◽  
Quantum Network ◽  
Quantum Networks ◽  
Fundamental Limitations ◽  
Process Framework ◽  
Entanglement Distribution ◽  
Near Term

Distributing entanglement over long distances is one of the central tasks in quantum networks. An important problem, especially for near-term quantum networks, is to develop optimal entanglement distribution protocols that take into account the limitations of current and near-term hardware, such as quantum memories with limited coherence time. We address this problem by initiating the study of quantum network protocols for entanglement distribution using the theory of decision processes, such that optimal protocols (referred to as policies in the context of decision processes) can be found using dynamic programming or reinforcement learning algorithms. As a first step, in this work we focus exclusively on the elementary link level. We start by defining a quantum decision process for elementary links, along with figures of merit for evaluating policies. We then provide two algorithms for determining policies, one of which we prove to be optimal (with respect to fidelity and success probability) among all policies. Then we show that the previously-studied memory-cutoff protocol can be phrased as a policy within our decision process framework, allowing us to obtain several new fundamental results about it. The conceptual developments and results of this work pave the way for the systematic study of the fundamental limitations of near-term quantum networks, and the requirements for physically realizing them.

scholarly journals Drone-based entanglement distribution towards mobile quantum networks

2020 ◽  
Vol 7 (5) ◽  
pp. 921-928 ◽  
Author(s):  
Hua-Ying Liu ◽  
Xiao-Hui Tian ◽  
Changsheng Gu ◽  
Pengfei Fan ◽  
Xin Ni ◽  
...  
Keyword(s):  
Quantum Communication ◽  
Single Mode ◽  
Cost Effective ◽  
Local Area ◽  
Single Mode Fiber ◽  
Full Time ◽  
Mobile Platforms ◽  
Quantum Networks ◽  
Entanglement Distribution ◽  
Scalable Design

Abstract Satellites have shown free-space quantum-communication ability; however, they are orbit-limited from full-time all-location coverage. Meanwhile, practical quantum networks require satellite constellations, which are complicated and expensive, whereas the airborne mobile quantum communication may be a practical alternative to offering full-time all-location multi-weather coverage in a cost-effective way. Here, we demonstrate the first mobile entanglement distribution based on drones, realizing multi-weather operation including daytime and rainy nights, with a Clauser-Horne-Shimony-Holt S-parameter measured to be 2.41 ± 0.14 and 2.49 ± 0.06, respectively. Such a system shows unparalleled mobility, flexibility and reconfigurability compared to the existing satellite and fiber-based quantum communication, and reveals its potential to establish a multinode quantum network, with a scalable design using symmetrical lens diameter and single-mode-fiber coupling. All key technologies have been developed to pack quantum nodes into lightweight mobile platforms for local-area coverage, and arouse further technical improvements to establish wide-area quantum networks with high-altitude mobile communication.

scholarly journals EntangleNet: Theoretical Reestablishment of Entanglement in Quantum Networks †

2018 ◽  
Vol 8 (10) ◽  
pp. 1935
Author(s):  
Mihai-Zicu Mina ◽  
Pantelimon Popescu
Keyword(s):  
Reliable Method ◽  
Entanglement Swapping ◽  
Quantum States ◽  
Entangled State ◽  
Quantum Network ◽  
Quantum Networks ◽  
Maximally Entangled State ◽  
Highly Sensitive ◽  
The Subject ◽  
Entanglement Distribution

In the practical context of quantum networks, the most reliable method of transmitting quantum information is via teleportation because quantum states are highly sensitive. However, teleportation consumes a shared maximally entangled state. Two parties Alice and Bob located at separate nodes that wish to reestablish their shared entanglement will not send entangled qubits directly to achieve this goal, but rather employ a more efficient mechanism that ensures minimal time resources. In this paper, we present a quantum routing scheme that exploits entanglement swapping to reestablish consumed entanglement. It improves and generalizes previous work on the subject and reduces the entanglement distribution time by a factor of 4 k in an arbitrary scale quantum network, where N = 4 k - 1 is a required number of quantum nodes located between source and destination. In addition, k is the greatest positive integer considered by Alice or Bob, such that afterwards they choose N quantum switches.

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
Keyword(s):  
Entangled States ◽  
Maximum Probability ◽  
Quantum Networks ◽  
Classical Communication ◽  
Bipartite State ◽  
Operational Interpretation ◽  
Entanglement Distribution ◽  
Entanglement Of Assistance ◽  
03.65 Ud ◽  
03.67 Mn

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

scholarly journals Practical figures of merit and thresholds for entanglement distribution in quantum networks

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Sumeet Khatri ◽  
Corey T. Matyas ◽  
Aliza U. Siddiqui ◽  
Jonathan P. Dowling
Keyword(s):  
Quantum Networks ◽  
Figures Of Merit ◽  
Entanglement Distribution
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