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arXiv · 2410.23269

A superconducting on-chip microwave cavity for tunable hybrid systems with optically trapped Rydberg atoms

Benedikt Wilde·Manuel Kaiser·Malte Reinschmidt·Andreas Günther·Dieter Koelle·Jószef Fortágh·Reinhold Kleiner·Daniel Bothner
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Abstract

Hybrid quantum systems are highly promising platforms for addressing important challenges of quantum information science and quantum sensing. Their implementation, however, is technologically non-trivial, since each component typically has unique experimental requirements. Here, we work towards a hybrid system consisting of a superconducting on-chip microwave circuit in a dilution refrigerator and optically trapped ultra-cold atoms. Specifically, we focus on the design optimization of a suitable superconducting chip and on the corresponding challenges and limitations. We unfold detailed microwave-cavity engineering strategies for maximized and tunable coupling rates to atomic Rydberg-Rydberg transitions in $\mathrm{^{87}Rb}$ atoms while respecting the boundary conditions due to the presence of a laser beam near the surface of the chip. Finally, we present an experimental implementation of the superconducting microwave chip and discuss the cavity characteristics as a function of temperature and applied dc voltage. Our results illuminate the required consideration aspects for a flexible, tunable superconductor-atom hybrid system, and lay the groundwork for realizing this exciting platform in a dilution refrigerator with vacuum Rabi frequencies approaching the strong-coupling regime.

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Benedikt Wilde, Manuel Kaiser, Malte Reinschmidt, Andreas Günther, Dieter Koelle, Jószef Fortágh, Reinhold Kleiner, Daniel Bothner. 2024-10-30. A superconducting on-chip microwave cavity for tunable hybrid systems with optically trapped Rydberg atoms. https://doi.org/10.1103/physrevapplied.23.064016

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