Theoretical physicists at Trinity College Dublin are amongst an international collab that has constructed the world’s smallest engine—which is as a single calcium ion, is roughly ten billion times smaller than a car engine.
Work carried out by Professor John Goold’s QuSys group in Trinity’s School of Physics describes the science behind this tiny motor. The research, published in the international journal Physical Review Letters, explains how random fluctuations affect the operation of microscopic machines. Sooner or later, such units could be integrated into other technologies to recycle waste heat and thus enhance energy efficiency.
The engine itself—a single calcium ion which is electrically charged, which makes it straightforward to trap utilizing electric fields. The working body of the engine is the ion’s “intrinsic spin.” This spin is used to transform heat absorbed from laser beams into oscillations, or vibrations, of the confined ion.
These vibrations work like a “flywheel,” which captures the helpful energy generated by the engine. This power is stored in discrete items known as “quanta,” as predicted by quantum mechanics.
“The flywheel permits us to truly measure the power yield of an atomic-scale motor, resolving single quanta of energy, for the first time,” stated Dr. Mark Mitchison of the QuSys group at Trinity, and one of the article’s co-authors.
Starting the flywheel from rest or, more precisely, from its ground state —the team noticed the little engine forcing the flywheel to run quicker and faster. Crucially, the state of the ion was available within the experiment, allowing the physicists to precisely assess the energy deposition process.