Multilevel electromagnetically-induced-transparency cooling
Phys. Rev. A 113, 013702 – Published 2 January, 2026
DOI: https://doi.org/10.1103/gnbd-8tpy
Abstract
Electromagnetically-induced-transparency (EIT) cooling is a well-established method for preparing trapped-ion systems in their motional ground state. However, isolating a three-level system, as required for EIT cooling, is often challenging or impractical. Nonetheless, multilevel systems can inherently host dark states. In this work we extend the EIT cooling framework to such multilevel systems. We develop a formalism to accurately determine the cooling rate in the weak-sideband-coupling regime and provide an approximate estimate for cooling rates beyond this regime, without the need for explicit simulation of the motional degree of freedom. We clarify the connection between the cooling rate and the absorption spectrum, offering a pathway for efficient near-ground-state cooling of ions with complex electronic structures.
