Relazione su invito

Ultraprecise frequency measurements without local clocks: going beyond the GPS limit via long-haul fiber links.

Clivati C., Cappellini G., Livi L.F., Poggiali F., Siciliani de Cumis M. Mancini M., Pagano G., Frittelli M., Mura A., Costanzo G. A., Levi F., Calonico D., Fallani L., Catani J., Inguscio M.
  Mercoledì 28/09   10:00 - 13:00   Edificio Psicologia 2 - Aula 2B   II - Fisica della materia
Global Positioning System (GPS) dissemination of frequency standards is widespread at present, as it currently provides the time and frequency reference for the majority of industrial and research applications worldwide. On the other hand, the ultimate limits of the GPS presently curb further advances in high-precision, scientific and industrial applications relying on this dissemination scheme. We will present a work in which we demonstrate that these limits can be reliably overcome even in laboratories without a local atomic clock by replacing the GPS with a 642 km long optical fiber link to a remote primary caesium frequency standard. Through this configuration we stably address the 1S0--3P0 clock transition in an ultracold gas of ${}^{173}Yb$, with a precision that exceeds the possibilities of a GPS-based measurement, dismissing the need for a local clock infrastructure to perform beyond-GPS high-precision tasks. We also report an improvement of two orders of magnitude in the accuracy on the transition frequency reported in the literature.