Precision measurement of the Ca+43 nuclear magnetic moment

Abstract

We report precision measurements of the nuclear magnetic moment of 43 Ca + , made by microwave spectroscopy of the 4s 2 S 1/2 |F = 4, M = 0 → |F = 3, M = 1 ground level hyperfine clock transition at a magnetic field of ≈ 146 G, using a single laser-cooled ion in a Paul trap. We measure a clock transition frequency of f = 3 199 941 076.918(43) Hz, from which we determine µI /µN = −1.315350(9)(1), where the error (9) arises from uncertainty in the hyperfine A constant, and the (1) arises from the uncertainty in our measurement. We make a second measurement which is less precise but agrees with the first. We use our µI value, in combination with previous NMR results, to extract the shielding constant of 43 Ca 2+ ions in D2O: σ = −0.00022(1).