Quantum coherence and ergotropy
Item Type:Journal Article
Citation:Francica G and Binder F C and Guarnieri G and Mitchison M. T and Goold J and Plastina F, Quantum coherence and ergotropy, Physical Review Letters, 125, 2020, 180603-
2006.05424.pdf (Accepted for publication (author's copy) - Peer Reviewed) 1.351Mb
Constraints on work extraction are fundamental to our operational understanding of the thermodynamics of both classical and quantum systems. In the quantum setting, finite-time control operations typically generate coherence in the instantaneous energy eigenbasis of the dynamical system. Thermodynamic cycles can, in principle, be designed to extract work from this nonequilibrium resource. Here, we isolate and study the quantum coherent component to the work yield in such protocols. Specifically, we identify a coherent contribution to the ergotropy (the maximum amount of unitarily extractable work via cyclical variation of Hamiltonian parameters). We show this by dividing the optimal transformation into an incoherent operation and a coherence extraction cycle. We obtain bounds for both the coherent and incoherent parts of the extractable work and discuss their saturation in specific settings. Our results are illustrated with several examples, including finite-dimensional systems and bosonic Gaussian states that describe recent experiments on quantum heat engines with a quantized load.
Type of material:Journal Article
Series/Report no:Physical Review Letters
Availability:Full text available