Evaluation of the systematic shifts of a single-40Ca+-ion frequency standard.

Progress on the evaluation of systematic frequency shifts is described in the development of the optical frequency standard based on single-trapped 40Ca+ with a "clock" transition at 729 nm. The overall systematic uncertainty of the 4s ²S1/2-3d ²D5/2 clock resonance has been characterized to be 7.8 x 10-16. This uncertainty is at a level similar to the Cs fountain primary standard, while the potential stability for the 40Ca+ clock exceeds that of Cs. [ABSTRACT FROM AUTHOR]