Date and Time:  16-June-2022 18:15-19:15

Speaker:  Prof. Mohsen Razavi, University of Leeds, Quantum Communications for ALL (QCALL) coordinator

Host: Gui-Lu Long (Tsinghua Univ.& BAQIS）

Title: Quantum communications at long distances

Abstract: 

Enabling quantum communications at arbitrarily long distances is a requirement for future quantum networks. The first step towards such an ambitious goal is to surpass the fundamental bounds on quantum communications rates over repeaterless links. In this talk, I focus on some of the solutions that can help us, in the short term, to achieve this objective. I use quantum key distribution (QKD) as the key application that can be used for benchmarking the suitability of each solution. These solutions include the newly proposed twin-field QKD. I will discuss the performance of these protocols under realistic conditions. I will also go over solutions that use a minimal number of quantum memories to improve the rate-versus-distance scaling. How to employ such memory-assisted systems in practice will be discussed as well. Finally, I go over the typical requirements for achieving a rate boost using encoded quantum repeaters, especially in nitrogen-vacancy-centre platforms.

About the Speaker:

Mohsen Razavi received his B.Sc. and M.Sc. degrees (with honours) in Electrical Engineering from Sharif University of Technology, Tehran, Iran, in 1998 and 2000, respectively. From August 1999 to June 2001, he was a member of research staff at Iran Telecommunications Research Centre, working on all-optical CDMA networks and the possible employment of optical amplifiers in such systems.  He joined the Research Laboratory of Electronics, at the Massachusetts Institute of Technology (MIT), in 2001 to pursue his Ph.D. degree in Electrical Engineering and Computer Science, which he completed in 2006. He continued his work at MIT as a Post-doctoral Associate during Fall 2006, before joining the Institute for Quantum Computing at the University of Waterloo as a Post-doctoral Fellow in January 2007. Since September 2009, he has been a Faculty Member at the School of Electronic and Electrical Engineering at the University of Leeds, where he is now a Professor. Prof Razavi is a recipient of the MIT-HP Alliance Fellowship and the Marie-Curie International Reintegration Grant. He chaired and organized the first International Workshop on Quantum Communication Networks in 2014, and has been a member of the organising/technical committee in several other events. He coordinated the European Innovative Training Network,  QCALL, which aimed at providing quantum communications services to all users.  Prof Razavi has authored an introductory  book on quantum communications networks published as part of IOP Concise Physics series. His research interests include a variety of topics in quantum and classical optical communications, quantum cryptography, quantum optics, and quantum networks.