Characterizing the spatial potential of a surface electrode ion trap

TL;DR

This paper presents a highly precise method for characterizing the spatial potential of surface electrode ion traps using a parametric model and multiple experimental data types, achieving superior accuracy over existing methods.

Contribution

It introduces a flexible optimization approach that combines various experimental data to accurately characterize the potential in surface electrode traps, reducing systematic errors.

Findings

Secular frequency errors within ±0.5%

Ion positional errors less than 1.2 μm

Enhanced accuracy over previous methods

Abstract

The accurate characterization of the spatial potential generated by a planar electrode in a surface-type Paul trap is of great interest. To achieve this, we employ a simple yet highly precise parametric expression to describe the spatial field of a rectangular-shaped electrode. Based on this, an optimization method is introduced to precisely characterize the axial electric field intensity created by the powered electrode and the stray field. In contrast to existing methods, various types of experimental data, such as the equilibrium position of ions in a linear string, equilibrium positions of single trapped ions and trap frequencies, are utilized for potential estimation in order to mitigate systematic errors. This approach offers significant flexibility in voltage settings for data collection, making it particularly well-suited for surface electrode traps where ion probe trapping height may vary with casual voltage settings. In our demonstration, we successfully minimized the discrepancy between experimental observations and model predictions to an impressive extent. The relative errors of secular frequencies were suppressed within $\pm$ 0.5$\%$, and the positional error of ions was limited to less than 1.2 $\mu$m, all surpassing those achieved by existing methodologies.