Single-atom imaging of ¹⁷³Yb in optical tweezers loaded by a five-beam magneto-optical trap

We report on the trapping and imaging of individual ytterbium atoms in arrays of optical tweezers, loaded from a magneto-optical trap (MOT) formed by only five beams in an orthogonal configuration. In our five-beam MOT, operating on the narrow 1 S 0 → 3 P 1 intercombination transition, gravity balances the radiation pressure of a single upward-directed beam. This approach enables efficient trapping and cooling of the most common ytterbium isotopes ( 171 Yb, 173 Yb and 174 Yb) to ≤ 20 μK at densities ~ 10 11 atoms/cm 3 within less than one second. This configuration allows for significantly reducing the complexity of the optical setup, potentially benefiting any ytterbium-atom based quantum science platform leveraging single-atom microscopy, from quantum processors to novel optical clocks. We then demonstrate the first single-atom-resolved imaging of the fermionic, large-spin isotope 173 Yb (I=5/2), employing a two-color imaging scheme that does not rely on magic-wavelength trapping. We achieve a high single-atom imaging fidelity of 99.96(1)% and a large survival probability of 98.5(2)%, despite large differential light shifts affecting all nuclear spin sublevels of the excited 3 P 1 state involved in the cooling transition. The demonstrated capabilities will play a key role in future quantum simulations and computing applications with 173 Yb arrays.