Calcium ion used as micro engine
23 Aug 2019
Theoretical physicists have used the intrinsic angular momentum of a calcium ion to effectively turn it into the world’s smallest engine.
An international team used the ion to convert heat absorbed from laser beams into oscillations. These vibrations act like a flywheel, in that they are able to store rotational energy in discrete units, or quanta.
Trinity College Dublin physicist Dr Mark Mitchison, told Laboratory News: “By measuring the state of the flywheel we can infer the work output of the engine with sufficient precision that individual units (quanta) of energy can be resolved.
“This allowed us to show that tiny fluctuations, which abound at such microscopic scales, significantly affected the engine’s operation.”
Future micro-devices that use this technique may be able to recycle waste heat or improve energy efficiency.
Professor John Goold at Trinity College Dublin said: "Heat management at the nanoscale is one of the fundamental bottlenecks for faster and more efficient computing.
“Understanding how thermodynamics can be applied in such microscopic settings is of paramount importance for future technologies."
The experiment was led by Professor Ferdinand Schmidt-Kaler and Dr Ulrich Poschinger of Johannes Gutenberg University (JGU) in Mainz, Germany.
JGU professors revealed a pilot prototype of the single ion heat engine in 2014 and published their experiment in 2016. This new paper reports a different experiment on a single-atom heat engine, but carried out by the same experimental team based in Mainz, Germany, with theoretical support from Trinity College Dublin researchers.
Dr Mitchison, who co-authored this new research, told Laboratory News that its main distinctions are that the new engine makes use of the intrinsic spin of the ion and incorporates the flywheel mechanism.
The research paper was published in Physical Review Letters.
