Adiabatic Rapid Passage for State Transfer and Sideband Cooling in an ⁸⁷Sr Optical Lattice Clock

Effcient population transfer and motional state control are important for optical lattice clocks and precision experiments with lattice-trapped neutral atoms. Here we experimentally investigate adiabatic rapid passage (ARP) on the clock transition of a one-dimensional ⁸⁷Sr optical lattice clock and develop a mode-resolved model for ARP on motional sidebands. On the carrier transition, ARP enables robust internal-state transfer with a maximum excitation fraction of 0.98(2). On the blue motional sideband, ARP increases the maximum excitation fraction from 0.47(2) to 0.55(3), and the measured dynamics are consistently reproduced by the mode-resolved model. The model further predicts that the sideband transfer effciency can exceed 0.88 when the carrier Rabi frequency is increased to 15 kHz. Applying ARP to the red-sideband cooling reduces the axial mean vibrational occupation to approximately 0.038, corresponding to a motional ground-state population of 0.96. These results provide a quantitative basis for designing ARP excitation on motional sidebands and for optimizing sideband cooling in lattice-trapped atoms, with direct relevance to coherent state preparation in optical lattice clocks and related precision-measurement experiments in neutral atoms.