title: High-accuracy measurement of the 113Cd+ ground-state hyperfine splitting at the milli-Hertz level.
abstract: We have developed a microwave frequency standard based on the 15.2 GHz ground-stated hyperfine transition of (113)C(+) ions. Using a laser-cooled ion cloud trapped in a linear quadrupole Paul trap, the clock transition frequency is measured to be 15 199 862 855.0125(87) Hz, with an accuracy at the 10(-13) level. The main errors are from the microwave frequency reference used in the experiment. The precision is improved by nearly two orders of magnitude than that reported before.
authors.affiliation: Joint Institute for Measurement Science, Tsinghua University, Beijing 100084, China.
authors.forename: S G
authors.initials: SG
authors.lastname: Wang
authors.forename: J W
authors.initials: JW
authors.lastname: Zhang
authors.forename: K
authors.initials: K
authors.lastname: Miao
authors.forename: Z B
authors.initials: ZB
authors.lastname: Wang
authors.forename: L J
authors.initials: LJ
authors.lastname: Wang
mesh_terms: D002104:Cadmium / Q000032:analysis* / Q000737:chemistry* / Q000528:radiation effects; D007554:Isotopes / Q000032:analysis / Q000737:chemistry; D007834:Lasers; D008422:Materials Testing; D008872:Microwaves; D009991:Oscillometry / Q000379:methods*
chemical_list: D007554:Isotopes; D002104:Cadmium