Millikelvin Spatial Thermometry of Trapped Ions

TL;DR

This paper introduces a high-resolution imaging method for millikelvin thermometry of trapped ions, providing accurate temperature measurements independent of cooling dynamics, revealing anisotropic ion behavior, and enabling new quantum system insights.

Contribution

The paper presents a novel millikelvin thermometry technique using high-resolution imaging that surpasses Doppler thermometry in accuracy and systematic error.

Findings

Achieved b5K accuracy and precision in ion temperature measurement.

Observed anisotropic ion dynamics with temperatures ranging from <60 mK to >15 K.

Demonstrated potential for studying quantum systems cooled by ions.

Abstract

We demonstrate millikelvin thermometry of laser cooled trapped ions with high-resolution imaging. This equilibrium approach is independent of the cooling dynamics and has lower systematic error than Doppler thermometry, with \pm5 mK accuracy and \pm1 mK precision. We used it to observe highly anisotropic dynamics of a single ion, finding temperatures of < 60 mK and > 15 K simultaneously along different directions. This thermometry technique can offer new insights into quantum systems sympathetically cooled by ions, including atoms, molecules, nanomechanical oscillators, and electric circuits.