Weighing of trapped ion crystals and its applications

TL;DR

This paper introduces a precise method for measuring the motion of trapped ion crystals using pulsed excitation and fluorescence analysis, enabling accurate mass measurements and collision observations.

Contribution

A novel scheme for measuring the secular motion of trapped ions with high precision using fluorescence analysis and pulsed excitation.

Findings

Measured ion crystal mode frequencies with better than 5e-4 precision

Determined ion masses accurately using the new method

Observed charge exchange collisions between calcium isotopes

Abstract

We have developed a novel scheme to measure the secular motion of trapped ions. Employing pulsed excitation and analysis of the fluorescence of laser cooled ions, we have measured the centre-of-mass mode frequency of single as well as entire ion crystals with a frequency precision better than 5e-4 within an interrogation time on the order of seconds, limited only by the fluorescence collection efficiency and the background noise. We have used this method to measure the mass of ions and observed charge exchange collisions between trapped calcium isotopes.