2025/06/10 by Ronen M. Kroeze, Kroeze, Ronen M., René A. Villela +7 · 1 citation
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Advanced Frequency and Time Standards #Mechanical and Optical Resonators
paper · doi:10.48550/arxiv.2506.09031
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 171Yb and bosonic 174Yb 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 171Yb with an average motional occupation of n≃0.015 and provide a direct comparison with 174Yb, 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.