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One of the scientific pursuits for which alkaline-earth atoms are most famous is optical atomic clocks. In atoms like Strontium and Ytterbium, there exists a long-lived optical transition known as the “clock transition”. Viewed as an oscillator, this transition has an intrinsic quality factor of in excess of��10¹⁷— that is, it can ring quadrillions of times before the oscillations die out. This means this oscillator can serve as an exceptional time-keeper, and, indeed, in the past decade, such optical atomic clocks have allowed some of the most precise measurements ever made by humans.

Another appealing aspect of alkaline-earth atoms is the presence of a second relatively narrow transition — though not as narrow as the clock transition — that can be used for ground-state laser cooling. This is especially powerful when combined with the possibility of rearranging optical tweezers to prepare arbitrary atomic distributions with very low entropy in the atomic spatial distribution. So far, large-scale demonstrations of atomic rearrangement have been used for spin models, with atoms that might be relatively hot in their motional degrees of freedom. In this project, we seek to prepare arbitrary distributions of scalable arrays of ground-state atoms for large scale itinerant models.

Unlike their bosonic counterpart, fermionic isotopes of alkaline-earth atoms benefit from having nuclear spin. This spin has been proposed for new many-body models, such as SU(N) physics, as well as the basis for new qubit architectures. In a new experiment, we seek to gain single-qubit-resolved control of arrays of Ytterbium-171 atoms, where quantum information is stored in the spin-1/2 nuclear spin of this isotope. We seek to engineer the resulting system to fully exploit the high two-qubit gate speeds possible with large Rydberg Rabi frequencies from the excited clock state.

In Rydberg-mediated two-qubit gates, a fundamental limit of gate fidelity comes from the finite-lifetime of the Rydberg state, which exhibits a significant contribution from blackbody-induced decay. Therefore, producing a cryogenic apparatus with high-optical access, compatible with these many directions, would have significant impact. At the same time, the inclusion of cryogenic pumping drastically improves the background vacuum pressure and therefore trapping lifetime, which can also significantly improve performance in these scientific endeavors.��