Motional-Mode Analysis of Trapped Ions

TL;DR

This paper introduces two methods for characterizing motional modes in trapped ions, crucial for precise control in scalable quantum computing architectures, demonstrated on $^{25}$Mg$^+$ ions near surface-electrode traps.

Contribution

It presents two novel methods for motional-mode characterization applicable to various trapping regimes, aiding in the control of ion motional degrees of freedom.

Findings

Methods successfully characterize motional modes in single ions.

Demonstrated control of ions near surface-electrode traps.

Applicable to both weak and strong-binding regimes.

Abstract

We present two methods for characterization of motional-mode configurations that are generally applicable to the weak and strong-binding limit of single or multiple trapped atomic ions. Our methods are essential to realize control of the individual as well as the common motional degrees of freedom. In particular, when implementing scalable radio-frequency trap architectures with decreasing ion-electrode distances, local curvatures of electric potentials need to be measured and adjusted precisely, e.g., to tune phonon tunneling and control effective spin-spin interaction. We demonstrate both methods using single $^{25}$Mg$^+$ ions that are individually confined $40\,\mu$m above a surface-electrode trap array and prepared close to the ground state of motion in three dimensions.