title: Passivity, complete passivity, and virtual temperatures.
abstract: We give a simple and intuitive proof that the only states which are completely passive, i.e., those states from which work cannot be extracted even with infinitely many copies, are Gibbs states at positive temperatures. The proof makes use of the idea of virtual temperatures, i.e., the association of temperatures to pairs of energy levels (transitions). We show that (1) passive states are those where every transition is at a positive temperature and (2) completely passive states are those where every transition is at the same positive temperature.
authors.affiliation: ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain.
authors.forename: Paul
authors.initials: P
authors.lastname: Skrzypczyk
authors.affiliation: H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
authors.forename: Ralph
authors.initials: R
authors.lastname: Silva
authors.affiliation: Département de Physique Théorique, Université de Genève, 1211 Genève, Switzerland.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Brunner