Resonant Few-Photon Excitation of a Single-Ion Oscillator

TL;DR

This paper demonstrates resonant excitation of a single trapped ion's motion using pulsed radiation, enabling efficient state readout for non-fluorescing ions through coherent motional buildup.

Contribution

It introduces a method for resonant, pulsed excitation of a single-ion oscillator that links internal quantum states to motional dynamics for improved spectroscopy.

Findings

Coherent oscillations build up after scattering ~100 photons.

Phase locking occurs rapidly to the drive.

Technique enables potential state readout of non-fluorescing ions.

Abstract

We study the motion of an undamped single-ion harmonic oscillator, resonantly driven with a pulsed radiation pressure force. We demonstrate that a barium ion, initially cooled to the Doppler limit, quickly phase locks to the drive and builds up coherent oscillations above the thermal distribution after scattering of order one hundred photons. In our experiment, this seeded motion is subsequently amplified and then analyzed by Doppler velocimetry. Since the coherent oscillation is conditional upon the internal quantum state of the ion, this motional excitation technique could be useful in atomic or molecular single-ion spectroscopy experiments, providing a simple protocol for state readout of non-fluorescing ions with partially closed-cycle transitions.