Experimental realization of fast ion separation in segmented Paul traps

TL;DR

This paper demonstrates a method for rapidly separating two ions in a segmented Paul trap with minimal motional excitation, using spectroscopic calibration and optimized control parameters, applicable to various trap geometries.

Contribution

The authors experimentally realize fast ion separation in segmented Paul traps with a novel calibration routine and control optimization, achieving low motional excitation within 80 microseconds.

Findings

Achieved minimum mean excitation of 4.16 vibrational quanta per ion at 80 μs separation

Controlled ion separation using three parameters: static tilt, voltage offset, and duration

Method is adaptable to different trap geometries without specific design requirements

Abstract

We experimentally demonstrate fast separation of a two-ion crystal in a microstructured segmented Paul trap. By the use of spectroscopic calibration routines for the electrostatic trap potentials, we achieve the required precise control of the ion trajectories near the \textit{critical point}, where the harmonic confinement by the external potential vanishes. The separation procedure can be controlled by three parameters: A static potential tilt, a voltage offset at the critical point, and the total duration of the process. We show how to optimize the control parameters by measurements of ion distances, trap frequencies and the final motional excitation. At a separation duration of $80 \mu$s, we achieve a minimum mean excitation of $\bar{n} = 4.16(0.16)$ vibrational quanta per ion, which is consistent with the adiabatic limit given by our particular trap. We show that for fast separation times, oscillatory motion is excited, while a predominantly thermal state is obtained for long times. The presented technique does not rely on specific trap geometry parameters and can therefore be adopted for different segmented traps.