Early Stage Quantum Networking

QTA programme science lead, University of Otago Associate Professor Dr Jevon Longdell builds “quantum memories” for light. They are devices where you can store and recall light in a way that preserves its precise quantum state. His group is now perfecting and adapting these for use in space-based quantum networks. The quantum networks will allow the distribution of entangled light over large distances with applications in secure communication, sensing and distributed quantum computing. In these networks the memories will play a key role in the quantum repeaters needed to counteract loss.Dr Longdell is leading a team of collaborators from Australia and the German Space Agency, DLR, which is exploring the use of two rare earth elements erbium, and europium. Erbium is used to make the amplifiers that boost signals in optical fibers and erbium-based quantum memories are easy to integrate with existing networks. Europium provides long term signal storage. Dr Longdell says if two erbium and europium memories can be entangled you can get the best of both worlds.Dr Longdell explains that erbium-doped quantum memories are easy to interface with light in optical fibre networks and europium memories have world record storage times. The interoperability between these memories will bring new capabilities to quantum networks.