Levitated timepiece sets new benchmark

Collaborating teams of scientists from the University of St Andrews in Scotland and the Institute of Scientific Instruments of the Czech Academy of Sciences in Brno manufactured a new type of mechanical “clock” composed of a birefringent sphere of the size of a blood cell oscillating in a light trap. The sphere moves in a vacuum to minimize its interaction with the environment and damping. The team managed to achieve perfect harmony between the movement of the sphere and tilting of its axis, similar to a child on a swing, which led to an increase in the accuracy of the frequency of the sphere's oscillations by two orders of magnitude compared to previous levitating objects. The quality Q of this oscillator has reached 100 million, which corresponds to a loss of about a millionth of a second in two days. Ultra-precise frequency sources are used for very precise synchronization of events, such as GPS positioning systems. Here, scientists have obtained a very sensitive tool for monitoring changes in the environment, e.g. pressure, or extremely weak forces acting on an oscillating ball, e.g. gravity.

https://news.st-andrews.ac.uk/archive/levitated-timepiece-sets-new-benchmark/


Online: https://advances.sciencemag.org/content/6/23/eaaz9858/tab-article-info

A calcium carbonate micro-sphere, the size of a cell, and levitated by light, acted as an ultra-stable oscillator (“clock”). Credit: Yoshi Arita (University of St Andrews and Chiba University).