Fluctuation theorems: work is not an observable.
The characteristic function of the work performed by an external time-dependent force on a Hamiltonian quantum system is identified with the time-ordered correlation function of the exponentiated system's Hamiltonian. A similar expression is obtained for the averaged exponential work which is related to the free energy difference of equilibrium systems by the Jarzynski work theorem.
Institute of Physics, University of Augsburg, Augsburg, Germany.
Peter
P
Talkner
Eric
E
Lutz
Peter
P
Hänggi