Array of Individual Circular Rydberg Atoms Trapped in Optical Tweezers.

Circular Rydberg atoms (CRAs), i.e., Rydberg atoms with maximal orbital momentum, are highly promising for quantum computation, simulation, and sensing. They combine long natural lifetimes with strong interatomic interactions and coupling to electromagnetic fields. Trapping individual CRAs is essential to harness these unique features. We report the first demonstration of CRAs laser trapping in a programmable array of optical bottle beams. We observe the decay of a trapped rubidium circular level over 5 ms using a novel optical detection method. This first optical detection of alkali CRAs is both spatially and level selective. We finally observe the mechanical oscillations of the CRAs in the traps. This work opens the route to the use of circular levels in quantum devices. It is also promising for quantum simulation and information processing using the full extent of Rydberg manifolds.

Laser Trapping of Circular Rydberg Atoms.

Rydberg atoms are remarkable tools for quantum simulation and computation. They are the focus of an intense experimental activity, mainly based on low-angular-momentum Rydberg states. Unfortunately, atomic motion and levels lifetime limit the experimental timescale to about 100 µs. Here, we demonstrate two-dimensional laser trapping of long-lived circular Rydberg states for up to 10 ms. Our method is very general and opens many opportunities for quantum technologies with Rydberg atoms. The 10 ms trapping time corresponds to thousands of interaction cycles in a circular-state-based quantum simulator. It is also promising for quantum metrology and quantum information with Rydberg atoms, by bringing atom-field interaction times into unprecedented regimes.

[Analysis of lesions from mandibular fractures in children. Therapeutic methods (author's transl)]. / Bilan lésionnel des fractures mandibulaires de l'enfant. Modalités thérapeutiques adoptées à l'Hôpital Bretonneau.

A statistical analysis was conducted in 22 recent cases of fracture and 4 cases of post-fracture ankylosis treated in the "Hôpital Bretonneau" over the last 5 years. The results demonstrated the frequency of often unrecognized associated condylar lesions (19 of 22 cases of recent fracture). They also emphasized the need to avoid conventional bimaxillary blocking, which when required should be conducted with the "open mouth", in cases of high or severe lesions of the mandibular condyles. Reconstruction of the condylar head involves re-insertion of the meniscular cap associated with regain of function, rather than conservation at any price of the condylar head, even recovered with its "fertile" cartilage.