Physics

Physicists Create World’s Smallest Engine – 10 Billion Times Smaller Than a Car Engine

The World's Smallest Engine

The world’s smallest engine works due to its intrinsic spin, which converts heat absorbed from laser beams into oscillations, or vibrations, of the trapped ion. Credit: Professor Goold, Trinity College Dublin.

Theoretical physicists at Trinity are among an international collaboration that has built the world’s smallest engine – which, as a single calcium ion, is approximately ten billion times smaller than a car engine.

Work performed 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. In the future, such devices could be incorporated into other technologies in order to recycle waste heat and thus improve energy efficiency.

The QuSys research group from Trinity College Dublin’s School of Physics, with Professor John Goold pictured in the back row, first left. Credit: Professor Goold, Trinity College Dublin.

The groundbreaking experiment was carried out by a research group led by Professor Ferdinand Schmidt-Kaler and Dr. Ulrich Poschinger of Johannes Gutenberg University in Mainz, Germany.

The engine itself – a single calcium ion – is electrically charged, which makes it easy to trap using electric fields. The working substance of the engine is the ion’s intrinsic “spin” (its angular momentum). This spin is used to convert heat absorbed from laser beams into oscillations, or vibrations, of the trapped ion.

These vibrations act like a “flywheel”, which captures the useful energy generated by the engine. This energy is stored in discrete units called “quanta”, as predicted by quantum mechanics.

“The flywheel allows us to actually measure the power output of an atomic-scale motor, resolving single quanta of energy, for the first time,” said 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 lowest energy in quantum physics) — the team observed the little engine forcing the flywheel to run faster and faster. Crucially, the state of the ion was accessible in the experiment, allowing the physicists to precisely assess the energy deposition process.

Assistant Professor in Physics at Trinity, John Goold said: “This experiment and theory ushers in a new era for the investigation of the energetics of technologies based on quantum theory, which is a topic at the core of our group’s research. 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.”

###

Professor Goold’s QuSys group is supported by a recently awarded ERC Starting Grant and an SFI-Royal Society University Research Fellowship.

The groundbreaking experiment was carried out by a research group led by Professor Ferdinand Schmidt-Kaler and Dr Ulrich Poschinger of Johannes Gutenberg University in Mainz, Germany.

References: “Spin Heat Engine Coupled to a Harmonic-Oscillator Flywheel” by D. von Lindenfels, O. Gräb, C. T. Schmiegelow, V. Kaushal, J. Schulz, Mark T. Mitchison, John Goold, F. Schmidt-Kaler and U. G. Poschinger, 22 August 2019, Physical Review Letters.
DOI: 10.1103/PhysRevLett.123.080602

Share
By
Trinity College Dublin

Recent Posts

Fatty Liver Disease: A Hidden Danger to Your Brain?

A study conducted by the Roger Williams Institute of Hepatology, affiliated with King's College London…

February 8, 2023

Space Mystery: Unexpected New Ring System Discovered in Our Own Solar System

ESA’s Cheops finds an unexpected ring around dwarf planet Quaoar During a break from looking…

February 8, 2023

Smart Energy Savings: Chameleon-Like Building Material Changes Its Infrared Color

To address the challenge of saving energy in the face of increasingly frequent extreme weather…

February 8, 2023

Cancer Conundrum Solved: Researchers Unravel a Population of ‘Cheating’ Cells

The study provides answers to multiple conundrums about cancer, while also uncovering new areas for…

February 8, 2023

Unlocking the Mystery of the Stellar Initial Mass Function: A New Breakthrough Discovery

The fate of galaxies is determined by the initial mass distribution at the birth of…

February 8, 2023

NASA Awards $11.7 Million to Historically Black Colleges and Universities

NASA is awarding $11.7 million to eight Historically Black Colleges and Universities (HBCUs) through the…

February 8, 2023