Quantum internet: A vision for the road ahead

Wehner, Stephanie; Elkouss, David; Hanson, Ronald K.

doi:10.1126/science.aam9288

Cited by 1,680 publications

(1,398 citation statements)

References 99 publications

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“…The ability to precisely evaluate the contribution due to different weather conditions will be crucial in many situations. The geographical sites with better conditions can be more precisely mapped, in order to optimize the structure of future global quantum networks [65][66][67][68][69]. Through the use of this model, the data from meteorological predictions can directly be linked to the key rate achievable by the QKD link, allowing more accurate statistical studies of the number of operative days per year.…”

Section: Resultsmentioning

confidence: 99%

Satellite-based links for quantum key distribution: beam effects and weather dependence

2019

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The establishment of a world-wide quantum communication network relies on the synergistic integration of satellite-based links and fiber-based networks. The first are helpful for long-distance communication, as the photon losses introduced by the optical fibers are too detrimental for lengths greater than about 200 km. This work aims at giving, on the one hand, a comprehensive and fundamental model for the losses suffered by the quantum signals during the propagation along an atmospheric free-space link. On the other hand, a performance analysis of different quantum key distribution (QKD) implementations is performed, including finite-key effects, focusing on different interesting practical scenarios. The specific approach that we chose allows to precisely model the contribution due to different weather conditions, paving the way towards more accurate feasibility studies of satellite-based QKD missions. IntroductionQuantum key distribution (QKD) and quantum communication in general have the potential to revolutionise the way we communicate confidential information over the internet. The natural carriers for quantum information are photons, that are already widely used in classical networks of optical fibers to achieve high communication rates. Unfortunately, even though enormous improvements have been obtained in the last years [1, 2], scaling quantum communication protocols over long distances is very challenging, due to the losses experienced during the propagation inside the optical fibers. Several schemes for the realization of quantum repeaters have been proposed in recent years, that could allow to bridge long distances and naturally be implemented inside a quantum communication network [3][4][5][6][7]. Considering the important technological hurdles that quantum repeaters should overcome before becoming useful, satellite-based free-space links look like the most practical way to achieve long-distance QKD in the short term [8]. They can take advantage of the satellite technology and the optical communication methods developed in the last decades in the classical case. Various feasibility studies had addressed this topic in the last twenty years [8][9][10][11] and several experiments have definitely proved that the technology involved is ready for deployment [12][13][14][15][16].Optical satellite-based links have the important drawback of being strongly dependent on the weather conditions [17][18][19][20]. The presence of turbulent eddies and scattering particles like haze or fog generates random fluctuations of the relative permittivity of the air, on different length-and time-scales. This phenomenon affects the light propagation in a complicated way, inducing random deviations and deformations of any optical beam sent through the atmosphere. It results in reduced transmittance, because of geometrical losses due to the finite collection aperture, and random modifications of the phase front. A comprehensive model of these effects is then necessary, in order to precisely evaluate the performance of the link w...

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Section: Resultsmentioning

confidence: 99%

Satellite-based links for quantum key distribution: beam effects and weather dependence

2019

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“…Quantum bit (qubit), as the fundamental building block for quantum computing and quantum network, can take various materialized forms in reality as long as the system comprises two distinct quantum states that can be coherently superpositioned, for example, the atomic clock states of trapped ion, the orthogonal polarization states of photon, the spin states of electron confined in a solid‐state potential, the superconducting state of micro‐circuit, and the emergent Majorana bound states featuring topological protection . All these candidates possess a finite coherence time imposed by the dephasing processes originating from the inevitable coupling to the host environment.…”

Section: Introductionmentioning

confidence: 99%

Building Blocks for Quantum Network Based on Group‐IV Split‐Vacancy Centers in Diamond

2019

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One ultimate goal of quantum information processing is to construct a quantum network for direct sharing of quantum information between distant parties based on stationary qubits for information storage and flying qubits for information transmission. This requires long‐lived quantum memories, efficient light–matter interface, and deterministic quantum gate operations. Among matter qubits, the electron spin of nitrogen vacancy center in diamond is an appealing option for its long coherence time at room temperature, deterministic microwave control, and optical preparation and readout of the qubit. However, its poor optical properties, including weak zero‐phonon‐line emission and large spectral diffusion, limit its potential for large‐scale deployment in quantum nodes. This has motivated the investigation for alternative quantum emitters that combine long‐time memory and coherent optical properties together. The emerging group‐IV split‐vacancy color centers in diamond, such as silicon‐vacancy, germanium‐vacancy, tin‐vacancy, and lead‐vacancy centers, are promising candidates of this ongoing exploration. These quantum emitters simultaneously possess microsecond spin coherence time and optically bright transitions with narrow linewidths. This review reports recent efforts on extending the spin coherence time of these color centers via temperature, strain, and charge control, which paves the road towards constructing solid‐based matter–photon interface for quantum network applications.

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“…The two forms of quantum repeaters may complement each other in a quantum network depending on the application in mind. Two‐way repeaters create entanglement between the stations establishing a quantum link between them to be used for, for example, distributed quantum computing or metrology . To this end, they require the availability of long‐term quantum memories at the repeater stations.…”

Section: Quantum Repeatersmentioning

confidence: 99%

Quantum Networks with Deterministic Spin–Photon Interfaces

2019

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This report considers how recent experimental progress on deterministic solid‐state spin–photon interfaces enables the construction of a number of key elements of quantum networks. After reviewing some of the recent experimental achievements, a discussion of their integration into Bell state analyzers, quantum non‐demolition detection, and photonic cluster state generation is presented. Finally, it is outlined how these elements can be used for long‐distance entanglement generation and quantum key distribution in a quantum network.

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Quantum internet: A vision for the road ahead

Cited by 1,680 publications

References 99 publications

Satellite-based links for quantum key distribution: beam effects and weather dependence

Satellite-based links for quantum key distribution: beam effects and weather dependence

Building Blocks for Quantum Network Based on Group‐IV Split‐Vacancy Centers in Diamond

Quantum Networks with Deterministic Spin–Photon Interfaces

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