The most accurate optical single-ion clock worldwide

Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. As early as 1981, Hans Dehmelt, who was to be awarded a Nobel prize later, had already developed the basic notions of how to use an ion kept in a high-frequency trap to build a clock which could attain the -- then unbelievably low -- relative measure-ment uncertainty in the range of 1E-18. Ever since, an i...