Probing fundamental symmetries of deformed nuclei in polyatomic molecules*

Precision measurements of Schiff moments in heavy, deformed nuclei — such as radium-225 — are sensitive probes of beyond standard model T, P violation in the hadronic sector. While the most stringent limits on Schiff moments to date are set with diamagnetic atoms, polar polyatomic molecules can offer higher sensitivities with unique experimental advantages. Here, we report on continuing theoretical progress in identifying and characterizing new "designer" polyatomic ions for Schiff moment measurements (i.e. RaOH+, RaSH+, RaOCH3+), which promise to support extended trapping and interrogation times. Internally, these molecular species possess mechanical doublets of opposite parity with small splittings, leading to full polarization at low fields, internal comagnetometer states useful for rejection of systematic effects, and the ability to perform sensitive searches for T, P violation using a small number of trapped ions containing heavy exotic nuclei.