Blackbody-radiation shift in a⁸⁸Sr⁺ion optical frequency standard

Abstract

The blackbody-radiation (BBR) shift of the 5s–4d5/2 clock transition in 88Sr+ is calculated to be 0.250(9) Hz at room temperature, T = 300 K, using the relativistic all-order method where all single and double excitations of the Dirac–Fock wavefunction are included to all orders of perturbation theory. The BBR shift is a major component in the uncertainty budget of the optical frequency standard based on the 88Sr+ trapped ion. The scalar polarizabilities of the 5s and 4d5/2 levels, as well as the tensor polarizability of the 4d5/2 level, are presented together with the evaluation of their uncertainties. The lifetimes of the 4d3/2, 4d5/2, 5p1/2 and 5p3/2 states are calculated and compared with experimental values.