Simulation and Optimization of Miniature Ring-Endcap Ion Traps

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 r_ring/r_endcap≈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.