Work

Narrowline Laser Cooling and Spectroscopy of Molecules via Stark States

Year: 2025

Type: article

Abstract: The electronic energy level structure of yttrium monoxide (YO) provides a long-lived, low-lying 2 Δ state ideal for high-precision molecular spectroscopy, narrowline laser cooling at the single photon-recoil limit, and studying dipolar physics with unprecedented interaction strength. High-resolution laser spectroscopy of ultracold laser-cooled YO molecules is used to study the Stark effect in the A ′ 2 Δ 3 / 2 J = 3 / 2 state. An immediate onset of the linear Stark effect is observed in the presence of weak applied electric fields due to the near-degenerate Λ doublet and the large electric dipole moment. By applying a small electric field the Stark-insensitive state is spectroscopically isolated and the absolute transition frequency to the X 2 Σ + electronic ground state is determined with a fractional frequency uncertainty of 9 × 10 − 12 . This electric field control is necessary to implement a quasi-closed photon-cycling scheme that preserves parity. With this scheme the first narrowline laser cooling of a molecule is demonstrated, reducing the temperature of sub-Doppler cooled YO in two dimensions.

Source: PRX Quantum

DOI: 10.1103/9v1s-d6bd