Optical spectroscopy of triply charged thorium - Alex Kuzmich

Atomic nuclei usually possess excitation energies in the keV to MeV range. A notable exception is the 229Th nucleus where the energy splitting of the ground state doublet is less than 10 eV. This fortuitous coincidence offers prospects for a next-generation clock and for a test of temporal variation of fundamental constants at an unprecedented level of precision. The monovalent character of the Th3+ ion is favorable for the isomer level search based on the electron bridge process. Optical spectroscopy of laser cooled and crystallized triply charged 229Th in a linear Paul trap will be presented. The nuclear excitation from the ground-electronic level of a single trapped, cold 229Th3+ ion is expected to be an ideal system for metrological applications.