Group seminar at MPQ and Zoom: Trapping circular Rydberg states of strontium in optical tweezers at 4K

Baptiste Muraz, Laboratoire Kastler Brossel Paris, France
Group seminar at MPQ lecture hall and Zoom
Thursday, 19 February, 09:00am (MEZ)

Rydberg atoms in optical tweezers have become a leading platform for both quantum simulation [1] and quantum computing [2]. However, they are often limited by their relatively short lifetime of a few tens of microseconds. One way to overcome this limitation is to use Rydberg atoms with maximum angular momentum (m = l = n-1), known as circular states. When placed in a cryogenic environment, these states can exhibit lifetimes of several milliseconds [3]. Circular states of alkaline-earth-like atoms offer additional advantages. They can be trapped in optical tweezers [4], and the optical transitions of the ionic core can be driven without autoionization [5]. In this talk, I will present our recent experimental progress in building a new apparatus in which we trap individual circular Rydberg strontium atoms in optical tweezers at 4K. In particular, I will show that the two-electron structure of strontium leads to coherent oscillations between singlet and triplet spin states, due to the spin-orbit coupling of the electron in the circular state.

[1] P. Scholl et al., Nature 595, 233–238 (2021).
[2] D. Bluvstein et al., Nature 626, 58-65 (2024).
[3] T. Cantat-Moltrecht et al., Phys. Rev. Research 2, 022032 (2020)
[4] J. T. Wilson et al., Phys. Rev. Lett. 128, 033201 (2022)
[5] R. C. Teixeira et al. , Phys. Rev. Lett. 125, 263001 (2020)