Observation of 1 S 0 → 3 P 0 Transition of a 40Ca+ - 27Al+ Quantum Logic Clock.

We report the realization of quantum logic spectroscopy on the¹S₀→ ³P₀clock transition of a single²⁷Al⁺ion. This ion is trapped together with a⁴⁰Ca⁺ion in a linear Paul trap, coupled by Coulomb repulsion, which provides sympathetic Doppler laser cooling and also the means for internal state detection of the clock state of the²⁷Al⁺ion. A repetitive quantum nondemolition measurement is performed to improve the fidelity of state detection. These techniques are applied to obtain clock spectroscopy at approximately 45 Hz. We also perform the preliminary locking on the¹S₀ → ³P₀clock transition. Our work is a fundamental step that is necessary toward obtaining an ultra-precision quantum logic clock based on⁴⁰Ca⁺-²⁷Al⁺ions. [ABSTRACT FROM AUTHOR]