Atomic electric dipole moments of He and Yb induced by nuclear Schiff moments

Abstract

We have calculated the atomic electric dipole moments (EDMs) d of ^3He and ^{171}Yb induced by their respective nuclear Schiff moments S. Our results are d(He)= 8.3x10^{-5} and d(Yb)= -1.9 in units 10^{-17}S/(e{fm}^3)e cm. By considering the nuclear Schiff moments induced by the parity and time-reversal violating nucleon-nucleon interaction we find d(^{171}Yb)~0.6d(^{199}Hg). For ^3He the nuclear EDM coupled with the hyperfine interaction gives a larger atomic EDM than the Schiff moment. The result for ^3He is required for a neutron EDM experiment that is under development, where ^3He is used as a comagnetometer. We find that the EDM for He is orders of magnitude smaller than the neutron EDM. The result for Yb is needed for the planning and interpretation of experiments that have been proposed to measure the EDM of this atom.