Prospects for atomic clocks based on large ion crystals

TL;DR

This paper explores the potential of large ion crystals for high-precision atomic clocks, demonstrating that certain effects can be managed to achieve stability comparable to neutral atom systems.

Contribution

It shows that large ion crystals can be used for atomic clocks with manageable systematic effects, opening new avenues for high-precision timekeeping.

Findings

Micromotion effects are not detrimental for clocks with negative differential static polarisability.

Quadrupole shifts from neighboring ions are negligible for clock performance.

Tensor polarisability effects can be compensated with a laser for small ion numbers.

Abstract

We investigate the feasibility of precision frequency metrology with large ion crystals. For clock candidates with a negative differential static polarisability, we show that micromotion effects should not impede the performance of the clock. Using Lu+ as a specific example, we show that quadrupole shifts due to the electric fields from neighbouring ions do not significantly affect clock performance. We also show that effects from the tensor polarisability can be effectively managed with a compensation laser at least for a small number of ions (<1000). These results provide new possibilities for ion-based atomic clocks, allowing them to achieve stability levels comparable to neutral atoms in optical lattices and a viable path to greater levels of accuracy.