Comparative studies of dipole polarizabilities in Sr${}^{+}$, Ba${}^{+}$ and Ra${}^{+}$ and their applications to optical clocks

Static dipole polarizabilities are calculated in the ground and metastable states of Sr${}^{+}$, Ba${}^{+}$ and Ra${}^{+}$ using the relativistic coupled-cluster method. Trends of the electron correlation effects are investigated in these atomic ions. We also estimate the Stark and black-body radiation shifts from these results for these systems for the transitions proposed for the optical frequency standards and compare them with available experimental data.