SCIENCE - Can a car engine be built out of a single particle?

(Phys.org)-As physicists work on miniaturizing devices, they will eventually run into the ultimate limit: the atom. A fundamental question in this area is whether it's even possible to scale down a macroscale engine such as a car engine to the single-particle level, while retaining the same working principles. In a new study, a team of physicists has proposed a scheme to build a heat engine that consists of a single trapped ion that can perform a quantum version of the Otto cycle, the basis of the common four-stroke car engine. If realized, the single-ion engine has the potential to enter the quantum regime and become a tool to investigate how quantum effects alter a nanoengine's efficiency.

http://phys.org/news273507273.html