Thesis defense of Kai-Niklas Schymik

Thesis defense of Kai-Niklas Schymik, PhD student in the Quantum optics group, on 24 March 2022 in the Auditorium of the Institut d'Optique Graduate School in Palaiseau, on the topic: "Scaling-up the Tweezer Platform - Trapping Arrays of Single Atoms in a Cryogenic Environment".

Abstract: "Tweezer atom arrays are a promising platform for the quantum simulation of spin models. As for most quantum simulation platforms, scaling up the number of individually controlled quantum objects is a major challenge. In this thesis, I present our work on lifting principal limitations to achieving large defect-free atom arrays with high fidelities. These limitations of the preparation fidelities include the vacuum-limited lifetime of a single atom in the tweezer, and the time needed to prepare large arrays atom-by-atom with a moveable optical tweezer. We first improved the assembly of large defect-free atom arrays by developing a new algorithmic framework. Using the new framework, we increased the number room-temperature setup. We then built a novel cryogenic atom tweezer platform in which the single-atom lifetime is over 6000 seconds, an approximately 300-fold improvement over our room-temperature experiment. We describe the design and construction of the new cryogenic setup and evaluate its performance in a series of tests. Finally, we demonstrate the trapping of single atoms in tweezer arrays at cryogenic temperatures and analyse different loss mechanisms present during the lifetime measurement. These results open the way to large-scale quantum simulations on our platform."