Nicoló Lo Piparo

Okinawa Institute of Science and Technology, Japan

24 October 2023 Tue 4 pm

                                      IBS Center for Theoretical Physics of Complex Systems (PCS), Administrative Office (B349), Theory Wing, 3rd floor

                                      Expo-ro 55, Yuseong-gu, Daejeon, South Korea, 34126 Tel: +82-42-878-8633                     

Exchanging quantum information over large distances is an essential task for the implementation of tomorrow’s quantum networks. However, due to channel loss, the information carried by photons decays exponentially with the distance, leading to extremely low performance. Quantum repeaters address this issue by splitting the communication channel into smaller segments in which entangled states are created and stored into quantum memories (QMs). Then through a series of entanglement swapping operations, the entanglement is extended to larger distances until the total communication distance is reached. The implementation of quantum repeater protocols is, however, extremely demanding because the QMs require high coherence times as well as high reading/writing efficiencies. In my talk I will present a quantum repeater protocol that does not require QMs while reaching high communication rates. This repeater protocol is based on the interaction of a specific class of bosonic states, called rotation symmetric bosonic codes (RSBCs), with matter qubits into cavity-QED. I will show the performance of this quantum repeater system embedded with such codes by calculating the secret key rate, i.e., the fraction of secure keys that two remote parties, Alice and Bob, can establish in a quantum key distribution (QKD) protocol. I will also show the advantages of using cluster states as main building blocks for this repeater protocol. Finally I will show how the costs for the implementation of such a system are of the same order or slightly better than other existing third generation quantum repeater systems.

  1. towards a more feasible implementation of quantum networks