Possibility of 0-g-factor paramagnetic molecules for measurement of the electron’s electric dipole moment

Abstract

The electric-field-dependent $g$ factor of the ground state of $^{2}\ensuremath{\Pi}_{1∕2}$ molecules is predicted cross zero at a specific value of electric field. Furthermore, $Edg∕dE$ evaluated at this field is expected to be small, allowing for extremely precise zeroing of the molecular magnetic moment. For the PbF molecule, we estimate this field to be $68\phantom{\rule{0.3em}{0ex}}\mathrm{kV}∕\mathrm{cm}$. If this prediction is correct, PbF could provide a uniquely sensitive probe of the electric dipole moment of the electron.