Rydberg-ion flywheel for quantum work storage

Trapped ions provide a platform for quantum technologies that offers long coherence times and high degrees of scalability and controllability. Here, we use this platform to develop a realistic model of a thermal device consisting of two laser-driven, strongly coupled Rydberg ions in a harmonic trap. We show that the translational degrees of freedom of this system can be utilized as a flywheel storing the work output that is generated by a cyclic thermodynamic process applied to its electronic degrees of freedom. Mimicking such a process through periodic variations of external control parameters, we use a mean-field approach underpinned by numerical and analytical calculations to identify relevant physical processes and to determine the charging rate of the flywheel. Our work paves the way for the design of microscopic thermal machines based on Rydberg ions that can be equipped with both many-body working media and universal work storages.