Towards an 27Al+ ions optical clock

Magnesium ion which acts as the logic ion in ²⁷ Al ₊ ion optical clock is trapped and laser cooled in a linear ion trap. Rabi oscillation between two hyperfine ground states of ²⁵ Mg ⁺ ion is observed and resonant frequency between two hyperfine ground states of ²⁵ Mg ⁺ 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 ²⁷ Al ⁺ 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.