Investigations of Ra+ properties to test possibilities for new optical-frequency standards

Abstract

The present work tests the suitability of the narrow transitions 7s 2S1/2-->6d 2D3/2 and 7s 2S1/2-->6d 2D5/2 in Ra+ for optical frequency standard studies. Our calculations of the lifetimes of the metastable 6d states using the relativistic coupled-cluster theory suggest that they are sufficiently long for Ra+ to be considered as a potential candidate for an atomic clock. This is further corroborated by our studies of the hyperfine interactions, dipole and quadrupole polarizabilities, and quadrupole moments of the appropriate states of this system.