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arXiv · 2212.06716

A high-cooperativity confocal cavity QED microscope

Ronen M. Kroeze·Brendan P. Marsh·Kuan-Yu Lin·Jonathan Keeling·Benjamin L. Lev
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Abstract

Cavity QED with cooperativity far greater than unity enables high-fidelity quantum sensing and information processing. The high-cooperativity regime is often reached through the use of short, single-mode resonators. More complicated multimode resonators, such as the near-confocal optical Fabry-P\'{e}rot cavity, can provide intracavity atomic imaging in addition to high cooperativity. This capability has recently proved important for exploring quantum many-body physics in the driven-dissipative setting. In this work, we show that a confocal cavity QED microscope can realize cooperativity in excess of 110. This cooperativity is on par with the very best single-mode cavities (which are far shorter) and 21$\times$ greater than single-mode resonators of similar length and mirror radii. The 1.7-$\mu$m imaging resolution is naturally identical to the photon-mediated interaction range. We measure these quantities by determining the threshold of cavity superradiance when small, optically tweezed Bose-Einstein condensates are pumped at various intracavity locations. Transmission measurements of an ex situ cavity corroborate these results. We provide a theoretical description that shows how cooperativity enhancement arises from the dispersive coupling to the atoms of many near-degenerate modes.

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Ronen M. Kroeze, Brendan P. Marsh, Kuan-Yu Lin, Jonathan Keeling, Benjamin L. Lev. 2022-12-13. A high-cooperativity confocal cavity QED microscope. https://doi.org/10.1103/prxquantum.4.020326

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