Direct Observation of Ion Micromotion in a Linear Paul Trap

TL;DR

This paper presents a novel, high-resolution method for directly observing and measuring ion micromotion in a linear Paul trap using a time-resolving camera, enabling detailed analysis of ion dynamics without extra equipment.

Contribution

A new micromotion measurement technique using a single-photon sensitive camera that captures fluorescence and position data at nanosecond resolution, applicable to complex ion arrangements.

Findings

Successful direct observation of ion micromotion in a crystal.

Measurement of micromotion amplitude and phase for individual ions.

Method does not require additional lasers or trap modulation.

Abstract

In this paper, direct observation of micromotion for multiple ions in a laser-cooled trapped ion crystal is discussed along with a novel measurement technique for micromotion amplitude. Micromotion is directly observed using a time-resolving, single-photon sensitive camera that provides both fluorescence and position data for each ion on the nanosecond time scale. Micromotion amplitude and phase for each ion in the crystal are measured, allowing this method to be sensitive to tilts and shifts of the ion chain from the null of the radiofrequency quadrupole potential in the linear trap. Spatial resolution makes this micromotion detection technique suitable for complex ion configurations, including two-dimensional geometries. It does not require any additional equipment or laser beams, and the modulation of the cooling lasers or trap voltages is not necessary for detection, as it is in other methods.