An elementary quantum network of single atoms in optical cavities

• Published in: Nature (London) 2012-04, Vol.484 (7393), p.195-200
• Main Authors: Ritter, Stephan, Nölleke, Christian, Hahn, Carolin, Reiserer, Andreas, Neuzner, Andreas, Uphoff, Manuel, Mücke, Martin, Figueroa, Eden, Bochmann, Joerg, Rempe, Gerhard
• Format: Article
• Language: English
• Subjects: 639/766/400/482; Atoms; Atoms & subatomic particles; Cavity quantum electrodynamics; micromasers; Classical and quantum physics: mechanics and fields; Coherence; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Holes; Humanities and Social Sciences; multidisciplinary; Network topologies; Networks; Optics; Phase transitions; Photons; Physics; Properties; Quantum communication; Quantum computation; Quantum computing; Quantum information; Quantum optics; Quantum theory; Qubits (quantum computing); Receiving; Releasing; Science; Science (multidisciplinary); Topology
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/nature11023

Quantum networks are distributed quantum many-body systems with tailored topology and controlled information exchange. They are the backbone of distributed quantum computing architectures and quantum communication. Here we present a prototype of such a quantum network based on single atoms embedded in optical cavities. We show that atom–cavity systems form universal nodes capable of sending, receiving, storing and releasing photonic quantum information. Quantum connectivity between nodes is achieved in the conceptually most fundamental way—by the coherent exchange of a single photon. We demonstrate the faithful transfer of an atomic quantum state and the creation of entanglement between two identical nodes in separate laboratories. The non-local state that is created is manipulated by local quantum bit (qubit) rotation. This efficient cavity-based approach to quantum networking is particularly promising because it offers a clear perspective for scalability, thus paving the way towards large-scale quantum networks and their applications. Single atoms in optical cavities in two separate laboratories are the nodes of an elementary quantum network, in which quantum information is distributed via the controlled emission and absorption of single photons. Towards quantum networking Quantum networks, following the principles of quantum teleportation, form the backbone of distributed quantum-computing architectures and quantum communication. This paper reports the first realization of an elementary quantum network with two quantum nodes based on single atoms trapped in optical cavities in separate laboratories. The approach is particularly promising in that it demonstrates all the necessary ingredients of a full-scale quantum network.