Speaker
Description
Precise timekeeping is indispensable in everyday life, science, and technology. It relies on reference oscillators with stable frequencies. Atomic clocks -- the most precise time-measurement devices at present -- use spectrally very narrow resonant transitions between electronic states in atoms as their reference oscillators. With the advent of hard x-ray FELs, the use of extremely narrow resonant transitions in atomic nuclei as reference oscillators for ultra-high-precision clocks is now within reach. Nuclear oscillators are naturally more stable and more resilient to external perturbations than their atomic counterparts. Resonant excitation of a ultra-narrow transition in Scandium-45 nuclear isomer with hard x-rays became recently possible [1] due to the high spectral photon flux delivered by the European XFEL in self-seeded high-repetition-rate mode. In this talk, the results of this experiment will be presented along with discussion of further developments of hard X-ray FELs required for ultra-high precision nuclear clocks.
[1] Shvyd'ko, Yu. et al. Resonant x-ray excitation of the nuclear clock isomer $^{45}$Sc. Nature 622 (2023) 471.
Funding Agency
Work at Argonne National Laboratory (ANL) was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract DE-AC02-06CH11357.
