A spin heat engine coupled to a harmonic-oscillator flywheel

Last updated October 7, 2020 by Alessandro Ferraro

Wednesday, February 12th 2020, 04:00 PM, Bell Lecture Theatre

Speaker: Mark Mitchison (Trinity College Dublin)

I will describe a recent experimental realisation of a heat engine comprising a single trapped ion, which performs work on a quantum load. The ion’s internal spin constitutes the working medium, while the ion’s quantised vibrations act as the load, or “flywheel”, that captures the output work. I will explain an intuitive theoretical model of the flywheel dynamics in terms of a random walk in phase space. Characterising the flywheel’s Husimi Q function allows us to measure the work output of a heat engine with single-quantum resolution for the first time. By inferring the ergotropy of the flywheel’s quantum state, we distinguish between useful work and useless thermal energy, thus elucidating how fluctuations fundamentally limit engine performance at the nanoscale.


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