Isotope-agnostic motional ground-state cooling of neutral Yb atoms
Ronen M. Kroeze, René A. Villela, Er Zu +2 more
Efficient high-fidelity ground-state cooling of motional degrees of freedom is crucial for applications in quantum simulation, computing, and metrology. Here, we demonstrate direct ground-state cooling of fermionic Yb 171 and bosonic Yb 174 atoms in two- and three-dimensional magic-wavelength optical lattices on the ultranarrow clock transition. Its high spectral resolution offers the potential for reaching extremely low temperatures. To ensure efficient cooling, we develop a chirped sideband cooling scheme, where we sweep the clock-laser frequency to mitigate the effects of spatial trap inhomogeneities. We further generalize the theoretical description of sideband spectra to higher-dimensional lattices for precise thermometry. We achieve 2D ground-state fractions of 97 % for Yb 171 with an average motional occupation of n ¯ ≃ 0.015 and provide a direct comparison with Yb 174 , reaching similar cooling performance. Applying the same scheme in 3D results in n ¯ ≃ 0.15 limited by layer-to-layer inhomogeneities in the vertical direction. These results demonstrate efficient motional ground-state cooling in optical lattices, especially for bosonic alkaline-earth(-like) atoms, where other methods are not applicable, opening the door to novel protocols for quantum science applications with neutral atoms.
arXiv:2506.09031•Physical Review Research•Nov 10, 2025•1 citation