Abstract:
The search for the electric dipole moment of the electron (eEDM) is important because it is a probe of Charge
Conjugation-Parity (CP) violation. It can also shed light on new physics beyond the standard model. It is not possible to
measure the eEDM directly. However, the interaction energy involving the effective electric field (Eeff) acting on an
electron in a molecule and the eEDM can be measured. This quantity can be combined with Eeff, which is calculated by
relativistic molecular orbital theory to determine eEDM. Previous calculations of Eeff were not sufficiently accurate in the
treatment of relativistic or electron correlation effects. We therefore developed a new method to calculate Eeff based on a
four-component relativistic coupled-cluster theory. We demonstrated our method for YbF molecule, one of the promising
candidates for the eEDM search. Using very large basis set and without freezing any core orbitals, we obtain a value of
23.1 GV/cm for Eeff in YbF with an estimated error of less than 10%. The error is assessed by comparison of our
calculations and experiments for two properties relevant for Eeff, permanent dipole moment and hyperfine coupling
constant. Our method paves the way to calculate properties of various kinds of molecules which can be described by a
single-reference wave function.
