A single-atom heat engine

TL;DR

This paper demonstrates a single-atom heat engine using a trapped ion, showing it can operate as a thermodynamic machine with measurable power and efficiency, pushing the limits of miniaturization in thermal machines.

Contribution

First experimental realization of a single-atom heat engine, providing insights into thermodynamics at the atomic scale.

Findings

Power output up to 342 yJ

Efficiency of 0.28%

Thermodynamic cycles characterized for various temperature differences

Abstract

We report the experimental realization of a single-atom heat engine. An ion is confined in a linear Paul trap with tapered geometry and driven thermally by coupling it alternately to hot and cold reservoirs. The output power of the engine is used to drive a harmonic oscillation. From direct measurements of the ion dynamics, we determine the thermodynamic cycles for various temperature differences of the reservoirs. We use these cycles to evaluate power $P$ and efficiency $\eta$ of the engine, obtaining up to $P=342\,$yJ and $\eta=0.28 \,\%$, consistent with analytical estimations. Our results demonstrate that thermal machines can be reduced to the ultimate limit of single atoms.