A spin heat engine coupled to a harmonic-oscillator flywheel
Abstract
We realize a heat engine using a single electron spin as a working medium. The spin pertains to the valence electron of a trapped Ca ion, and heat reservoirs are emulated by controlling the spin polarization via optical pumping. The engine is coupled to the ion's harmonic-oscillator degree of freedom via spin-dependent optical forces. The oscillator stores the work produced by the heat engine and therefore acts as a flywheel. We characterize the state of the flywheel by reconstructing the Husimi function of the oscillator after different engine runtimes. This allows us to infer both the deposited energy and the corresponding fluctuations throughout the onset of operation, starting in the oscillator ground state. In order to understand the energetics of the flywheel, we determine its ergotropy, i.e. the maximum amount of work which can be further extracted from it. Our results demonstrate how the intrinsic fluctuations of a microscopic heat engine fundamentally limit performance.
Keywords
Cite
@article{arxiv.1808.02390,
title = {A spin heat engine coupled to a harmonic-oscillator flywheel},
author = {David von Lindenfels and Oliver Gräb and Christian T. Schmiegelow and Vidyut Kaushal and Jonas Schulz and Mark T. Mitchison and John Goold and Ferdinand Schmidt-Kaler and Ulrich G. Poschinger},
journal= {arXiv preprint arXiv:1808.02390},
year = {2019}
}