The extraction of work from quantum coherence

Understand

The interplay between quantum-mechanical properties, such as coherence, and classical notions, such as energy, is a subtle topic at the forefront of quantum thermodynamics.

• The traditional Carnot argument limits the conversion of heat to work; here we critically assess the problem of converting coherence to work.
• Through a careful account of all resources involved in the thermodynamic transformations within a fully quantum-mechanical treatment, we show that there exist thermal machines extracting work from coherence arbitrarily well.
• Such machines only need to act on individual copies of a state and can be reused.