Description of the thesis topic

Quantum states in continuous variables (CV) represent a promising approach in quantum computing and communication. They offer significant advantages over discrete variable states (such as single-photon states), including deterministic generation and efficient detection. In particular, multimode squeezed states are essential for synthesizing cluster states, which are considered one of the most promising architectures for all-optical measurement-based quantum computation.
However, non-classical states generated from squeezing sources belong to the class of Gaussian states, which are insufficient for universal quantum computation. As a result, various de-Gaussification methods are being explored. These methods, however, are generally probabilistic and suffer from significant limitations in terms of generation rate and efficiency. Recently, attention has shifted toward deterministic sources capable of generating non-Gaussian states in continuous variables. These approaches rely on the implementation of nonlinear interactions characterized by Hamiltonians of higher than quadratic order. So far, research has primarily focused on single-mode states, such as generalized squeezing and cubic-gate states.
This project aims to achieve significant advancements in understanding the structure of non-Gaussian
quantum states and to develop new mathematical methodologies for their characterization. By
leveraging nonlinear canonical transformations, we seek to explore new avenues for deterministic non-
Gaussian state generation, which could lead to breakthrough applications in continuous-variable
quantum computing and quantum technologies.

Work Context

The position is primarily based in Lille, on the Cité Scientifique campus in Villeneuve d'Ascq. The recruited candidate will join the "Quantum Systems" team at the PhLAM Laboratory, which consists of six permanent members whose research activities span a wide range, from experimental physics of cold atoms and Bose-Einstein condensates to field theory and quantum information theory.

The PhD candidate will be co-supervised by Dr. Giuseppe Patera from the University of Lille – PhLAM and Prof. Rémy Boyer from the University of Lille – CRIStAL Lab, ensuring a strong interdisciplinary framework and broadening the expertise available for the project. The recruited candidate will also collaborate with other teams on campus, in particular with Prof. Stephan de Bièvre from the University of Lille – Laboratoire Paul Painlevé.

The position falls within a sector subject to the protection of scientific and technical potential (PPST) and therefore requires prior authorization from the competent authority of the MESR in accordance with regulations.

Constraints and risks

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