When exciting the valence electron of an atom to high energy levels, the atom as a whole gains exquisite properties. The so-called Rydberg atoms have been widely used in the past decades in vast range of applications: quantum information, quantum optics, quantum sensing and quantum simulations. These experiments exploit the very good coupling of these atoms to microwave radiation fields, the strong dipole-dipole interactions between two such atoms, or their long lifetimes, in the range of few 100µs for laser-accessible levels.
Among them, circular Rydberg atoms play a special role. Those giant atoms, with maximum orbital angular momentum, are lookalikes of the semi-classical Bohr atom. They have particularly long lifetimes, of few tens of ms. Used as two-level atoms, one of the simplest quantum systems, they have been instrumental to fundamental tests of quantum physics . Their high sensitivity to electric and magnetic fields make them appealing for quantum sensing. They are also promising for novel routes in quantum simulations of spin systems .
In this talk, I will present the main aspects and interests of atomic physics with Rydberg atoms. I will then focus on the experiments that have been performed with circular Rydberg atoms, in the CQED group of LKB. In particular, I will present our novel platform where we intend on realising quantum simulations of interacting spins with such atoms. I will report on our latest experimental results, regarding the preparation and manipulation of circular Rydberg levels from laser-cooled atoms in a cryostat. In particular, I will show how we have recently been able to laser trap circular Rydberg atoms in a hollow light tube .
 S. Haroche, RMP 85, 1083 (2013)
 T. L. Nguyen et al., PRX 8, 011032 (2018)
 R. Cortiñas et al., arXiv:1911.02316
Coffee and pastries at 11h00