Quantum repeater in quantum networks (Conference Presentation)

2019 ◽  
Author(s):  
William J. Munro ◽  
Kae Nemoto
Keyword(s):  
Quantum Repeater ◽  
Quantum Networks

scholarly journals Optical Quantum Memory and its Applications in Quantum Communication Systems

2020 ◽  
Vol 125 ◽  
Author(s):  
Lijun Ma ◽  
Oliver Slattery ◽  
Xiao Tang
Keyword(s):  
Communication Systems ◽  
Quantum Systems ◽  
Quantum Memory ◽  
Research Progress ◽  
Quantum Communications ◽  
Quantum Repeater ◽  
Quantum Networks ◽  
And Performance ◽  
The Impact ◽  
Photon Source

Optical quantum memory is a device that can store the quantum state of photons and retrieve it on demand and with high fidelity. It is emerging as an essential device to enhance security, speed, scalability, and performance of many quantum systems used in communications, computing, metrology, and more. In this paper, we will specifically consider the impact of optical quantum memory on quantum communications systems. Following a general overview of the theoretical and experimental research progress in optical quantum memory, we will outline its role in quantum communications, including as a photon source, photon interference, quantum key distribution (QKD), quantum teleportation, quantum repeater, and quantum networks.

Towards quantum networks of single spins: analysis of a quantum memory with an optical interface in diamond

2015 ◽  
Vol 184 ◽  
pp. 173-182 ◽  
Author(s):  
M. S. Blok ◽  
N. Kalb ◽  
A. Reiserer ◽  
T. H. Taminiau ◽  
R. Hanson
Keyword(s):  
Quantum Information Processing ◽  
Quantum States ◽  
Nitrogen Vacancy ◽  
Nuclear Spins ◽  
Quantum Repeater ◽  
Quantum Networks ◽  
Entanglement Generation ◽  
Quantum Bit ◽  
Single Defect ◽  
Coupling Parameters

Single defect centers in diamond have emerged as a powerful platform for quantum optics experiments and quantum information processing tasks. Connecting spatially separated nodes via optical photons into a quantum network will enable distributed quantum computing and long-range quantum communication. Initial experiments on trapped atoms and ions as well as defects in diamond have demonstrated entanglement between two nodes over several meters. To realize multi-node networks, additional quantum bit systems that store quantum states while new entanglement links are established are highly desirable. Such memories allow for entanglement distillation, purification and quantum repeater protocols that extend the size, speed and distance of the network. However, to be effective, the memory must be robust against the entanglement generation protocol, which typically must be repeated many times. Here we evaluate the prospects of using carbon nuclear spins in diamond as quantum memories that are compatible with quantum networks based on single nitrogen vacancy (NV) defects in diamond. We present a theoretical framework to describe the dephasing of the nuclear spins under repeated generation of NV spin-photon entanglement and show that quantum states can be stored during hundreds of repetitions using typical experimental coupling parameters. This result demonstrates that nuclear spins with weak hyperfine couplings are promising quantum memories for quantum networks.

scholarly journals Optical Quantum Memory and its Applications in Quantum Communication Systems

2019 ◽  
Vol 124 ◽  
Author(s):  
Lijun Ma ◽  
Oliver Slattery ◽  
Xiao Tang
Keyword(s):  
Communication Systems ◽  
Quantum Systems ◽  
Quantum Memory ◽  
Research Progress ◽  
Quantum Communications ◽  
Quantum Repeater ◽  
Quantum Networks ◽  
And Performance ◽  
The Impact ◽  
Photon Source

Optical quantum memory is a device that can store the quantum state of photons and retrieve it on demand and with high fidelity. It is emerging as an essential device to enhance security, speed, scalability, and performance of many quantum systems used in communications, computing, metrology, and more. In this paper, we will specifically consider the impact of optical quantum memory on quantum communications systems. Following a general overview of the theoretical and experimental research progress in optical quantum memory, we will outline its role in quantum communications, including as a photon source, photon interference, quantum key distribution (QKD), quantum teleportation, quantum repeater, and quantum networks.

scholarly journals Parameter regimes for surpassing the PLOB bound with error-corrected qudit repeaters

Quantum ◽  
2019 ◽  
Vol 3 ◽  
pp. 216 ◽  
Author(s):  
Daniel Miller ◽  
Timo Holz ◽  
Hermann Kampermann ◽  
Dagmar Bruß
Keyword(s):  
Secure Communication ◽  
Quantum Communication ◽  
Quantum Repeater ◽  
Long Distance ◽  
Quantum Networks ◽  
Quantum Capacity ◽  
Higher Dimensional ◽  
Quantum Repeaters ◽  
New Applications ◽  
Provably Secure

A potential quantum internet would open up the possibility of realizing numerous new applications, including provably secure communication. Since losses of photons limit long-distance, direct quantum communication and wide-spread quantum networks, quantum repeaters are needed. The so-called PLOB-repeaterless bound [Pirandola et al., Nat. Commun. 8, 15043 (2017)] is a fundamental limit on the quantum capacity of direct quantum communication. Here, we analytically derive the quantum-repeater gain for error-corrected, one-way quantum repeaters based on higher-dimensional qudits for two different physical encodings: Fock and multimode qudits. We identify parameter regimes in which such quantum repeaters can surpass the PLOB-repeaterless bound and systematically analyze how typical parameters manifest themselves in the quantum-repeater gain. This benchmarking provides a guideline for the implementation of error-corrected qudit repeaters.

scholarly journals Entangling single atoms over 33 km telecom fibre

2022 ◽  
Author(s):  
Tim van Leent ◽  
Matthias Bock ◽  
Florian Fertig ◽  
Robert Garthoff ◽  
Sebastian Eppelt ◽  
...  
Keyword(s):  
Large Scale ◽  
Quantum Communication ◽  
Frequency Conversion ◽  
Single Atom ◽  
Quantum Network ◽  
Low Loss ◽  
Quantum Repeater ◽  
Long Distance ◽  
Quantum Networks ◽  
Network Links

Abstract Heralded entanglement between distant quantum memories is the key resource for quantum networks. Based on quantum repeater protocols, these networks will facilitate efficient large-scale quantum communication and distributed quantum computing. However, despite vast efforts, long-distance fibre based network links have not been realized yet. Here we present results demonstrating heralded entanglement between two independent, remote single-atom quantum memories generated over fibre links with a total length up to 33 km. To overcome the attenuation losses in the long optical fibres of photons initially emitted by the Rubidium quantum memories, we employ polarization-preserving quantum frequency conversion to the low loss telecom band. The presented work represents a milestone towards the realization of efficient quantum network links.

scholarly journals Quantum dot technology for quantum repeaters: from entangled photon generation towards the integration with quantum memories

2021 ◽  
Author(s):  
Julia Neuwirth ◽  
Francesco Basso Basset ◽  
Michele B. Rota ◽  
Emanuele Roccia ◽  
Christian Schimpf ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Communication ◽  
Special Focus ◽  
Quantum Repeater ◽  
Long Distance ◽  
Quantum Networks ◽  
Pair Generation ◽  
The One ◽  
Photon Generation ◽  
High Degree

Abstract The realization of a functional quantum repeater is one of the major research goals in long-distance quantum communication. Among the different approaches that are being followed, the one relying on quantum memories interfaced with deterministic quantum emitters is considered as one of the most promising solutions. In this work, we focus on the hardware to implement memory-based quantum-repeater schemes that rely on semiconductor quantum dots for the generation of polarization entangled photons. Going through the most relevant figures of merit related to efficiency of the photon source, we select significant developments in fabrication, processing and tuning techniques aimed at combining high degree of entanglement with on-demand pair generation, with a special focus on the progress achieved in the representative case of the GaAs system. We proceed to offer a perspective on integration with quantum memories, both highlighting preliminary works on natural-artificial atomic interfaces and commenting a wide choice of currently available and potentially viable memory solutions in terms of wavelength, bandwidth and noise-requirements. To complete the overview, we also present recent implementations of entanglement-based quantum communication protocols with quantum dots and highlight the next challenges ahead for the implementation of practical quantum networks.

Fragmentation-aware Entanglement Routing for Quantum Networks

2021 ◽  
pp. 1-1
Author(s):  
Shengyu Zhang ◽  
Shouqian Shi ◽  
Chen Qian ◽  
Kwan L. Yeung
Keyword(s):  
Quantum Networks
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