Our second seminar will take place at Jussieu, Pierre & Marie Curie Campus, amphitheater 25 from 11.45 am to 12.30 pm on Wednesday, the 7th of July

For this second seminar, our 2 speakers are Raja Yehia, from QI team at Lip6 and Thibaut Lacroix, from PHOCOS (Photonique et cohérence de spin) at INSP.

From 11:45 am to 12:05 pm
Environment-mediated communication in nanoscale devices using tensor networks - Thibaut Lacroix
Nanoscale devices - either biological or artificial - operate in a regime where the usual assumptions of a structureless bath spectral density and Markovian bath don't hold. Being able to predict and study the dynamics of such systems is crucial and is usually done by tracing out the bath degrees of freedom. We present a numerically exact method using a Matrix Product State representation of the quantum state of a system and its environment with a specific example of an interaction that depends on the spatial structure of the system.
The result is a non-Markovian dynamics where long-range couplings induce correlations into the environment. The environment dynamics can be naturally extracted from our method and shine a light on long time feedback effects that are responsible for the observed non-Markovian recurrences in the eigen-populations.

From 12:10 pm to 12.30pm
Metropolitan Quantum Network architecture towards a Quantum Internet - Raja Yehia
Research on quantum networks has reached a phase where experimental progress is interlacing with conceptual principle in the development of a Quantum Internet. More and more effort is put into finding the best topology, physical platform and system architecture to enhance today's Internet with quantum properties. To find a way to efficiently route entanglement to many users modularly would allow the use of all sort of new applications such as conference key agreement, anonymous transmission, delegated computing or clock synchronization.
In this talk I will present a realizable architecture for a photonic quantum network in a metropolitan area that minimizes the cost in hardware resource for end users. Using NetSquid, a quantum network simulation tool using discrete events, I perform various simulation of different QKD protocols as well as multiparty protocols while trying to consider all errors and losses. Using state of the art but realistic parameters in our model we show that quantum-enhanced network functionalities could appear in our day-to-day life in not such a long time.

After the talks and if the weather allows us to do it, we invite you to join us for lunch at the Arènes de Lutèce. Just grab a sandwich on your way and meet us here to discuss and share a convivial moment.