
@PRL Second Law in an Optical Cavity and a BEC
In the continuum from quantum to classical, there exists a paradox. Classical machines like heaters cannot run in reverse (and effectively act as refrigerators) without extra energy. Such a scenario would violate the second law of thermodynamics, which states that entropy must always increase. In contrast, the equations of quantum mechanics imply that quantum processes can run in reverse. Currently, researchers are unclear on how to reconcile the two frameworks. To that end,