Classical information networks such as the internet have revolutionized our way of transmitting and processing data. Now, scientists are trying to build the quantum version of such networks, which hold promise to provide radically new capabilities compared to their classical counterparts. Quantum information networks (consisting of matter quantum nodes and quantum communication channels) could for example enable perfectly secure data transmission or enhanced data processing via distributed quantum computing. While it is generally agreed that photons are the best choice to transmit quantum information, the optimal matter system for building the quantum nodes is still an open question, as each system provides different functionalities. Therefore, the implementation of a hybrid network has been proposed, searching to combine the best capabilities of different material systems.

In this talk, I will present our recent results demonstrating photonic quantum communication between two very distinct quantum nodes functioning at very different wavelengths placed in different laboratories, using a single photon as information carrier. The emitting node was a laser-cooled cloud of Rubidium atoms and the receiving node a crystal doped with Praseodymium ions. We transmitted a qubit from one system to the other, using quantum frequency conversion techniques. The results of the study have shown that two very different quantum systems can be connected and can communicate by means of a single photon and represent an elementary “hybrid” quantum network link.


Friday, May 4, 2018, 12:00. ICFO Auditorium