Towards an 27Al+ ion optical clock

Abstract： Magnesium ion which acts as the logic ion in 27Al+ ion optical clock is trapped and laser cooled in a linear ion trap. Rabi oscillation between two hyperfine ground states of 25Mg+ ion is observed and resonant frequency between two hyperfine ground states of 25Mg+ ion is measured. Earth magnetic field is compensated with three pairs of mutually perpendicular Helmholtz coils. Light shift induced by the Raman cooling beams is measured. With the photo-ionization laser of Al, Al+ ion is trapped together with Mg+ ion. The linewidth of the clock laser of the 27Al+ ion is measured to be about 0.8 Hz. The Allan deviation of the beat note from two independent lasers is 6.5*10-15 at 1s.