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

TL;DR

This paper introduces a novel method to induce a significant light shift on Rydberg states of alkaline-earth atoms via Isolated Core Excitation, effectively avoiding auto-ionization and enabling advanced quantum simulation capabilities.

Contribution

The study demonstrates a new approach to control Rydberg states in alkaline-earth atoms using ICE without auto-ionization, supported by spectroscopic analysis and quantum defect theory.

Findings

Successful application of ICE to induce light shifts in ytterbium Rydberg states

Auto-ionization effects are accurately modeled and minimized

Enhanced control of Rydberg states for quantum simulation

Abstract

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.