A future quantum network will consist of quantum processors that are connected by quantum
channels, just like conventional computers are wired up to form the Internet. In contrast to …

Coherent interfaces between optical photons and long-lived matter qubits form a key
resource for a broad range of quantum technologies. Cavity quantum electrodynamics …

Quantum communication brings radically new capabilities that are provably impossible to
attain in any classical network. Here, we take the first step from a physics experiment to a …

Solid-state single-photon sources are central building blocks in quantum information
processing. Atomically thin crystals have emerged as sources of nonclassical light; however …

The nitrogen-vacancy (NV) center in diamond has an optically addressable, highly coherent
spin. However, a NV center even in high-quality single-crystalline material is a very poor …

Quantum channels enable the implementation of communication tasks inaccessible to their
classical counterparts. The most famous example is the distribution of secret key. However …

The stability and outstanding coherence of dopants and other atomlike defects in tailored
host crystals make them a leading platform for the implementation of distributed quantum …

Large-scale quantum communication networks require quantum repeaters due to the signal
attenuation in optical fibers. Ideal quantum repeater nodes efficiently link a quantum memory …

We report on the conversion to telecommunication wavelengths of single photons emitted by
a nitrogen-vacancy (NV) defect in diamond. By means of difference frequency generation …

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 …