1304.1060 (Johan Aberg)

Catalytic coherence    [PDF]

Johan Aberg

Conservation of energy implies that we cannot freely create superpositions between energy eigenstates, while access to coherence enables such processes. A simple example of the latter is when an atom is put into a superposition of two energy levels, using coherent radiation in form of a laser. The question is to what extent the coherence is degraded when utilized. Here we show that coherence can be turned into a catalytic resource, meaning that it can be used indefinitely to induce coherent operations without ever being degraded. As an application we consider quantum thermodynamics, where we demonstrate that access to sufficient coherence enables the release of all latent expected work content in a system. Since we can make it a catalyst, no coherence is spent to achieve this work extraction. In a wider perspective, the fact that coherence can be made catalytic provides a step towards a characterization of the relation between energy and coherence as resources in quantum statistical mechanics.

View original: http://arxiv.org/abs/1304.1060