A short introduction on quantum thermodynamics is given and three new topics
are discussed: 1) Maximal work extraction from a finite quantum system. The
thermodynamic prediction fails and a new, general result is derived, the
``ergotropy''. 2) In work extraction from two-temperature setups, the presence
of correlations can push the effective efficiency beyond the Carnot bound. 3)
In the presence of level crossing, non-slow changes may be more optimal than
slow ones.Comment: 5 pages. Talk given at Physics of Quantum Electronics (PQE2004),
Snowbird, by Th.M. Nieuwenhuize