Towards an 27Al+ ions 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.