In this lecture Dr Margolis will describe the art of high accuracy and stable time-keeping using an atomic reference, namely a single trapped ion.
Helen Margolis is a Principal Research Scientist at the UK National Physical Laboratory in Teddington, Middlesex, where she is a member of the group developing optical atomic clocks, with particular responsibility for optical frequency metrology using femtosecond combs.
Her interest in precision measurement dates back to her time as a DPhil student and postdoctoral research assistant at the University of Oxford, where she worked on experiments designed to test the theory of quantum electrodynamics by spectroscopy of highly charged few-electron ions.
The past few years have seen enormous advances in the development of new types of atomic clock based on optical atomic transitions.
Because such clocks operate at much higher frequency than the current generation of microwave atomic clocks, they divide time into smaller slices, and therefore offer the prospect of significantly better stability and accuracy.
At NPL we are developing optical atomic clocks based on extremely narrow transitions in single trapped ions.
In this talk I will describe how we observe a single ion, how we make a laser stable enough to probe the narrow clock transition and how we measure a frequency that is too high to count directly.
The potential applications of optical atomic clocks, ranging from improved satellite navigation systems to experimental tests of general relativity, will also be discussed.