Aleksander N. Petrov

The YbOH molecule is a sensitive system to use in searches for fundamental symmetry violations. Its molecular-frame permanent and transition dipole moments are of key importance for preparing and interpreting experiments. We calculate these quantities for the lowest bending vibrational modes of the ground electronic state. A high-level coupled cluster method for electronic structure calculations, together with averaging over vibrational states, was employed to obtain accurate values.

Triatomic cation 175LuOH+, featuring near-degenerate, opposite-parity l-doublets, offers enhanced sensitivity to P- and T-violating interactions. We present ab initio calculations of its electronic structure and rovibrational structure beyond the rigid-ligand approximation by explicitly including OH-ligand deformation together with bending and stretching motions. Potential-energy surfaces are computed at the relativistic coupled cluster level of theory. The nuclear Schrodinger equation in Jacobi coordinates is solved by means of a coupled-channel expansion. Ligand deformation reduces the bending frequency by a few percent and increases the l-doubling constant q, while the stretching frequencies and rotational constants remain largely unchanged. For the first excited bending level, we predict ΔEJ=1 = 2q ≈ 24.9–26.4 MHz. These results establish LuOH+ as a viable platform for precision searches for CP-violating physics via the electron electric dipole moment and the nuclear magnetic quadrupole moment.

Molecules containing short-lived, radioactive nuclei are uniquely positioned to enable a wide range of scientific discoveries in the areas of fundamental symmetries, astrophysics, nuclear structure, and chemistry. Recent advances in the ability to create, cool, and control complex molecules down to the quantum level, along with recent and upcoming advances in radioactive species production at several facilities around the world, create a compelling opportunity to coordinate and combine these efforts to bring precision measurement and control to molecules containing extreme nuclei. In this manuscript, we review the scientific case for studying radioactive molecules, discuss recent atomic, molecular, nuclear, astrophysical, and chemical advances which provide the foundation for their study, describe the facilities where these species are and will be produced, and provide an outlook for the future of this nascent field.