Nonlinearity and Quantumness in Thermodynamics: From Principles to Technologies

The impact of quantum mechanics on thermodynamics, particularly on the principles and designs of heat machines (HM), has been limited by the incompatibility of quantum coherent evolution with the dissipative, open-system nature of all existing HM and their basic structure, which has not been radically changed since Carnot. We have recently proposed a paradigm change whereby conventional HM functionality is replaced by that of few-mode coherent, closed systems with nonlinear, e.g. cross-Kerr, inter-mode couplings. These couplings allow us to coherently filter incident thermal noise, transforming it into a resource of work and information. Current technological advances enable heat engines, noise sensors or microscopes based on such designs to operate with thermal noise sources of few photons. This paradigm shift opens a path towards radically new understanding and exploitation of the relation between coherent, quantum or classical, evolution and thermodynamic behavior.