Thesis defense of Guillaume BORNET

Thesis defense of Guillaume BORNET, PhD student in the Quantum optics group of the Laboratoire Charles Fabry, on 27 September 2024 at 2:00pm in the Auditorium of the Institut d'Optique Graduate School in Palaiseau, on the topic: "Quantum simulation of the dipolar XY model using arrays of Rydberg atoms."

Abstract: "During my four years of Ph.D. research, I focused on the implementation and study of the dipolar XY spin model using a Rydberg atom-based quantum simulator, where the atoms are coupled through resonant Rydberg-Rydberg dipole interactions (see figure). We utilized our ability to address individual atoms in arrays to adiabatically prepare and study the properties of the 2D square dipolar XY ground state, which exhibits complex antiferromagnetic and ferromagnetic order.

In addition, we demonstrated that the dipolar XY model can produce spin-squeezed states, which are particularly interesting in quantum metrology for enhancing measurement sensitivity. We characterized this squeezing, showing that it is scalable, meaning that its metrological gain (squeezing parameter) increases with system size. Finally, we conducted quench spectroscopy experiments to probe the dispersion relation of XY magnets in both the antiferromagnetic and ferromagnetic cases.

Our studies can be generalized to any system exhibiting dipolar interactions, such as ultra-cold molecules, magnetic atoms, or solid-state spin defects. The presentation will conclude with a discussion of ongoing work and prospects for future projects."