Towards Laser Cooling and Trapping of Group IV Atoms and Application to Measurement of Parity Violation in Atomic Sn

Recent progress in molecular laser cooling has demonstrated the viability of optical cycling on a Type-II transition (e.g. J → J' = J-1) for all typical stages of laser cooling and trapping. Inspired by this motif, we present here a novel scheme for laser cooling and trapping of Group IV (a.k.a. Group 14 or tetrel) atoms, such as silicon (Si), germanium (Ge), tin (Sn), and lead (Pb). These elements all possess a strong, fully closed Type-II transition between the metastable p^{2 3}P₁ state to the excited ps ³P₀^o state at accessible wavelengths, making them amenable to laser cooling and trapping. We focus on the application of this scheme to Sn, which has several features that make it attractive for precision measurement applications. For instance, Sn has the longest chain of spin-zero isotopes found in nature, and neutral Sn contains several clock transitions between metastable states. This makes Sn a promising candidate both for King-plot methods to detect new forces via isotope shifts, and for studying isotopic variation of atomic parity violation (APV) with enhanced sensitivity. We discuss simulation results indicating that capture into a red-detuned magneto-optical trap (MOT), followed by a blue-detuned MOT for sub-Doppler cooling and confinement, are both feasible in Sn. We also outline the projected sensitivity of a future APV measurement in Sn.