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With the decrease in dimension of ion traps employed in optical frequency standards and precision spectroscopy, the sensitivity of trapping behavior to trap geometry is more and more prominent. We present a guide for the design and construction of a miniature trap for a single ion confinement, and propose an optimized combination of rring/rendcap ≈ 0.5 and z0 ≈ r0 within the range of r0 = 0.7 ± 0.2 mm. Compared with the trap used by Huang et al. [Phys. Rev. A 84 (2011) 053841], the design can lead to an increase in trap pseudo-potential of more than 20% and a reduction on potential anharmonicity of more than 90%. The improvements make the trap closer to an ideal hyperboloidal trap to confine a single ion tightly with the benefit of weaker micro-motion. Considering the imperfection of electrodes machining and traps alignment, we also demonstrate the importance of trap symmetry, especially on two endcap electrodes. [ABSTRACT FROM AUTHOR]

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]

We achieve the sympathetic sideband cooling of a 40Ca+–27Al+ pair. Both axial modes of the two-ion chain are cooled simultaneously to near the ground state of the motion. The center of mass mode is cooled to an average phonon number of 0.052(9), and the breathing mode is cooled to 0.035(6). The heating rates of both a single 40Ca+ and the 40Ca+–27Al+ pair are measured and compared. This work is a fundamental step toward the implementation of a 40Ca+–27Al+ quantum logic clock. [ABSTRACT FROM AUTHOR]