Dynamics of axialized laser-cooled ions in a Penning trap

TL;DR

This paper experimentally demonstrates axialization in a Penning trap, significantly enhancing the damping of magnetron motion, which is crucial for quantum information applications, and confirms the resonant nature of the process.

Contribution

It provides the first experimental characterization of axialization in a Penning trap, showing increased damping rates and resonant behavior, advancing quantum information processing potential.

Findings

Order-of-magnitude increase in damping rate of magnetron motion

Observation of classical avoided crossing in motional frequencies

Good qualitative agreement with theoretical predictions

Abstract

We report the experimental characterization of axialization - a method of reducing the magnetron motion of a small number of ions stored in a Penning trap. This is an important step in the investigation of the suitability of Penning traps for quantum information processing. The magnetron motion was coupled to the laser-cooled modified cyclotron motion by the application of a near-resonant oscillating quadrupole potential (the "axialization drive"). Measurement of cooling rates of the radial motions of the ions showed an order-of-magnitude increase in the damping rate of the magnetron motion with the axialization drive applied. The experimental results are in good qualitative agreement with a recent theoretical study. In particular, a classical avoided crossing was observed in the motional frequencies as the axialization drive frequency was swept through the optimum value, proving that axialization is indeed a resonant effect.