High-Fidelity, Low-Loss State Detection of Alkali Atoms in Optical Tweezers

State detection often limits the performance of alkali atoms in optical tweezer platforms, which are widely used for studies in areas such as quantum computing, many-body physics, and quantum chemistry. Typical detection schemes use state-dependent atom loss, but this imposes a vacuum-dependent upper bound on readout fidelity, slows repetition rate, and complicates algorithms with mid-circuit measurement. An alternate atom retaining method is to collect state-dependent fluorescence photons. Until now, (without cavity enhancement) this technique has only been demonstrated to ≥ 1.2(2)% readout error (Fuhrmanek et al., 2011).

In work towards Rydberg-dressing quantum computation, we demonstrate hyperfine state readout of individual cesium atoms in optical tweezers with 0.09(2)% infidelity and low loss. After further study of relevant atom-photon interaction physics, we obtain this result via adaptive measurement and careful choice of detection parameters to minimize depumping and heating. Our techniques impose no stringent vacuum or optical requirements and can be readily adopted to improve detection on similar systems.