Paper detail

A Coherent Light Shift on Alkaline-Earth Rydberg Atoms from Isolated Core Excitation without Auto-Ionization

New experimental quantum simulation platforms have recently been implemented with divalent atoms trapped in optical tweezer arrays with promising performance. The second valence electron also brings new propects through the so-called Isolated Core Excitation (ICE), however autoionization presents a strong limitation to this use. In this study, we propose and demonstrate a new approach to applying a sizable light shift to a Rydberg state with close-to-resonant ICE while avoiding auto-ionization. In particular, we have investigated ICE of ytterbium atoms in $^1S_0$ Rydberg states. Spectroscopic studies of the induced auto-ionization and the light shift imparted to the Rydberg states are perfectly accounted for with Multi-channel Quantum Defect Theory. Such a control over the inner electron without disturbing the Rydberg electron brings a new tool for the targeted, coherent manipulation of Rydberg states in quantum simulation experiments performed with alkaline-earth atoms.