Searching for the electric dipole moment of the electron with trapped molecular ions

Precision spectroscopy of molecules is complementary to studies with high-energy colliders in the pursuit of physics beyond the Standard Model. Our search for a permanent electric dipole moment (EDM) in an electron constitutes a background free measurement of T-symmetry violation attempting to explain the origin of the matter/antimatter asymmetry in the universe. Due to our choice of molecular ions, which are easily trappable, we can select molecular species such as HfF+ and ThF+ that have enhanced sensitivity to the eEDM, while simultaneously benefiting from long interrogation times. We have recently attained >2 s spin-coherence duration and a 20-fold increase in ion count rate with precise control of the molecular internal state in our next generation measurement with HfF+. I will discuss the noise-immune detection scheme we developed to reach the quantum projection noise limit in our measurement, overcoming technical noise that becomes proportionally more significant in our newly achieved large samples. Our statistical uncertainty is now 40 times better at 3 x 10−29 e cm in one hour of integration time and will potentially break the current upper bound set on the eEDM, which is currently found to be consistent with 0. I will also discuss our new experiment design for the future measurement with ThF+ molecules, where >20 s coherence times are predicted and a further 20-fold improvement in overall sensitivity over the HfF+ experiment.