Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor Gerhard Rempe at the Max Planck Institute of Quantum Optics have now achieved a major breakthrough: they demonstrated the long-lived storage of a photonic qubit on a single atom trapped in an optical resonator.
The coherence time of the stored quantum bit outlasts 100 milliseconds and therefore matches the requirement for the creation of a global quantum network in which qubits are directly teleported between end nodes.
Direct teleportation between the end nodes of a network can be utilized to prevent the loss of precious quantum bits. In 2011, Professor Rempe’s group has demonstrated a successful technique for storing a photonic quantum bit on a single atom. Ultimately, the photon is absorbed by the atom and the quantum bit is transferred into a coherent superposition of two atomic states. Before the retrieval of the stored photonic quantum bit, the Raman transition is reversed.
“Although an envisioned global quantum network which allows for secure and reliable transport of quantum information still demands a lot of research, the long-lived storage of quantum bits is one of the key technologies and we believe that the current improvements will bring us a significant step closer to its realization.”