Clock-sideband cooling of neutral Yb atoms in magic lattices

We have demonstrated cooling to the absolute motional ground state of Yb in 2D and 3D optical lattices, utilizing the ultranarrow optical clock transition. The study has appeared online in our latest preprint.

Reaching ultralow temperatures is critical for applications in quantum simulation, computing and metrology. Alkaline-earth(-like) atoms are ideally suited for many such applications, but achieving efficient and rapid cooling to the absolute motional ground state remains a significant challenge. We demonstrate how both ¹⁷¹Yb and ¹⁷⁴Yb can be cooled to the motional ground state using resolved sideband cooling on the ultranarrow optical clock transition pervasive to alkaline-earth(-like) atoms. Effective operation of this technique in 2D and 3D optical lattice requires chirping the sideband frequency, despite a magic trapping wavelength. With this chirped clock sideband cooling we reach ultra-low average motional occupation of 0.015 for ¹⁷¹Yb and comparable performance in ¹⁷⁴Yb. We show straightforward extension of the technique to 3D. The experimental results are underpinned by a robust theory describing sideband spectroscopy using ultranarrow transitions in higher-dimensional lattices. These results open exciting new possibilities for rapid assembly of ultracold neutral atoms in optical lattices for quantum simulation of itinerant particles. Additionally, an efficient path towards high ground-state fractions opens the door for realizing 3D lattice clocks of ¹⁷⁴Yb for applications in quantum information and metrology.

Original publication:
Isotope-agnostic motional ground-state cooling of neutral Yb atoms
Ronen M. Kroeze, René A. Villela, Er Zu, Tim O. Höhn, Monika Aidelsburger

arXiv:2506.09031