Distributed entanglement and teleportation on a quantum network

We report on the realization of a multi-node quantum network. Using the network, we have demonstrated three protocols; generation of a entangled state shared by all nodes, entanglement swapping and quantum teleportation between non-neighboring nodes.

Realization of a multinode quantum network of remote solid-state qubits

The distribution of entangled states across the nodes of a future quantum internet will unlock fundamentally new technologies. Here, we report on the realization of a three-node entanglement-based quantum network. We combine remote quantum nodes based on diamond communication qubits into a scalable phase-stabilized architecture, supplemented...

Near-term quantum-repeater experiments with nitrogen-vacancy centers: Overcoming the limitations of direct transmission

Quantum channels enable the implementation of communication tasks inaccessible to their classical counterparts. The most famous example is the distribution of secret key. However, in the absence of quantum repeaters, the rate at which these tasks can be performed is dictated by the losses in the quantum channel. In practice, channel losses...

Entanglement between a Diamond Spin Qubit and a Photonic Time-Bin Qubit at Telecom Wavelength

We report on the realization and verification of quantum entanglement between a nitrogen-vacancy electron spin qubit and a telecom-band photonic qubit. First we generate entanglement between the spin qubit and a 637 nm photonic time-bin qubit, followed by photonic quantum frequency conversion that transfers the entanglement to a 1588 nm...

Dephasing mechanisms of diamond-based nuclear-spin memories for quantum networks

We probe dephasing mechanisms within a quantum network node consisting of a single nitrogen-vacancy center electron spin that is hyperfine coupled to surrounding C13 nuclear-spin quantum memories. Previous studies have analyzed memory dephasing caused by the stochastic electron-spin reset process, which is a component of optical internode...

Deterministic delivery of remote entanglement on a quantum network

Large-scale quantum networks promise to enable secure communication, distributed quantum computing, enhanced sensing and fundamental tests of quantum mechanics through the distribution of entanglement across nodes ^1-7. Moving beyond current two-node networks ^8-13 requires the rate of entanglement generation between nodes...

Multiplexed entanglement generation over quantum networks using multi-qubit nodes

Quantum networks distributed over distances greater than a few kilometres will be limited by the time required for information to propagate between nodes. We analyse protocols that are able to circumvent this bottleneck by employing multi-qubit nodes and multiplexing. For each protocol, we investigate the key network parameters that determine...

Entanglement distillation between solid-state quantum network nodes

The impact of future quantum networks hinges on high-quality quantum entanglement shared between network nodes. Unavoidable imperfections necessitate a means to improve remote entanglement by local quantum operations. We realize entanglement distillation on a quantum network primitive of distant electron-nuclear two-qubit nodes. The heralded...

Towards Legal Knowledge Management Systems for Regulatory Compliance

Maintaining regulatory compliance is an increasing concern. Legal Knowledge Management systems could support the work of compliance managers. However, there are challenges to overcome, of interpreting legal knowledge and mapping it onto business processes. In this discussion paper we determine requirements for Legal Knowledge Management systems...

Realization of a quantum standard for AC voltage: Overview of a European research project

Completion of large-bore high pressure/high temperature wells: Design and experience

Comparison of three-dimensional turbulent boundary layer calculations with experiment

The results of several three-dimensional turbulent boundary layer calculations have been compared with each other and with experiment for a number of test cases. The calculation methods applied range from integral methods to field methods using a turbulence model based upon the Reynolds stress transport equations. The test cases comprise various...

European Research Programme on Viscous Flows: Eurovisc Annual Report 1982