EIT cooling ¹⁷¹Yb atoms in magic-wavelength optical lattice

Cooling atoms trapped in an optical dipole potential is complicated by the different AC Stark (light) shifts on the various electronic states and typically requires the optical trap to be at a “magic” wavelength that causes identical shifts for the relevant energy levels. Magic trapping potentials are especially important when using narrow-linewidth transitions common in alkaline-earth(-like) atoms such as Sr and Yb. The ¹S₀ – ³P₁ transition in ¹⁷¹Yb has several useful magic wavelengths, including one halfway between the two hyperfine levels of the ³P₁ state. Using a magic trapping potential, we perform narrow-line Doppler cooling and sub-Doppler dark-state cooling based on electromagnetically induced transparency (EIT). EIT cooling is effective over a wide range of trap vibrational frequencies and has cooling timescale ∼1 ms. These features hold promise for quickly cooling large numbers of trapped atoms near or below the photon-recoil energy, which could be useful for preparing ultracold atom samples for interferometry, clocks, and other atomic physics experiments.