An atom in a cavity between two mirrors (left) acts as a heat engine in a driven-dissipative quantum system in which energy ...

The laws of thermodynamics state that heat naturally flows from hotter systems or regions to colder systems or regions until a state of thermal equilibrium is reached. This simple principle underpins ...

A tiny machine made from just an atom and particles of light may sound impossibly simple, but it raises a surprisingly difficult question: what counts as heat, and what energy can still do useful work ...