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 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 run times. 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.
- Received 14 August 2018
- Revised 31 May 2019
DOI:https://doi.org/10.1103/PhysRevLett.123.080602
© 2019 American Physical Society
Physics Subject Headings (PhySH)
Synopsis
A Heat Engine Made of a Single Ion Spin
Published 22 August 2019
By converting electron spin into ion motion, researchers build a simple heat engine out of a single calcium ion.
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