ERC consolidator grant COQCOoN ( PI: Valentina Parigi –

Complex network theory has provided a deep insight of complex systems, assembling theoretical tools able to the describe dynamical behavior of biological, social and technological structures. During the recent years a new area applying network theory and complex networks to quantum physical systems has emerged [1,2,4]. May complex networks structures help us to have a better understanding of the quantum world? Which kind of complex networks will be used in future quantum information technologies? The ERC project COQCOoN  is going to tackle the subject via theory and experiments based on multimode optical quantum networks.

The Multimode quantum optics group at Laboratoire Kastler Brossel (C. Fabre, N. Treps, V. Parigi and M. Walschaers) is one of the main actors in devising experimental setups for producing cluster states, i.e. large entangled networks useful in quantum information protocol on a large scale.   We recently demonstrated that these networks can be reshaped at will, and they can even take the complex structure of the real-world information networks, like internet [3,4,5,6].

The PhD project concerns the experimental implementation of quantum complex networks via femtosecond laser sources at telecom wavelengths, which are the most suitable for long-range fiber-based quantum communications and allow for the exploitation of the already existent integrated components developed in classical communications. The goal is the implementation of advanced quantum information protocols; theoretical activity can also be included in the project.

Practical information: applicants should have a Master diploma in Physics. Familiarity with quantum information and/or experimental optics will be valuable.

Starting date: Fall 2020. Location: Laboratoire Kastler Brossel (Paris).

For inquires, expression of interest and applications write to Application should include a CV, a motivation letter and reference names and should be sent not later than 30th of June 2020.

[1] G. Bianconi “Interdisciplinary and physics challenges of network theory” Europhys. Lett. 11156001 (2015)

[2]J. Biamonte, M. Faccin, and M. De Domenico, Complex networks from classical to quantum, Communications Physics 2, 53 (2019).

[3] Y. Cai, J. Roslund, G. Ferrini, F. Arzani, X. Xu, C. Fabre, N. Treps, “Multimode entanglement in reconfigurable graph states using optical frequency combs”, Nature Communication 8, 15645 (2017).

[4] J. Nokkala, F. Arzani, F. Galve, R. Zambrini, S. Maniscalco, J. Piilo, N. Treps, V. Parigi, Reconfigurable optical implementation of quantum complex networks, New J. Phys. 20, 053024 (2018)

[5] F. Sansavini and V. Parigi “Continuous variables graph states shaped as complex networks: optimization and manipulation” Entropy 22, 26 (2020)

[6] M. Walschaers, S. Sarkar, V. Parigi, and N. Treps “Tailoring Non-Gaussian Continuous-Variable Graph States”, Phys. Rev. Lett. 121, 220501  (2018)