title: Nonequilibrium quantum fluctuations of work.
abstract: The concept of work is basic for statistical thermodynamics. To gain a fuller understanding of work and its (quantum) features, it needs to be represented as an average of a fluctuating quantity. Here I focus on the work done between two moments of time for a thermally isolated quantum system driven by a time-dependent Hamiltonian. I formulate two natural conditions needed for the fluctuating work to be physically meaningful for a system that starts its evolution from a nonequilibrium state. The existing definitions do not satisfy these conditions due to issues that are traced back to noncommutativity. I propose a definition of fluctuating work that is free of previous drawbacks and that applies for a wide class of nonequilibrium initial states. It allows the deduction of a generalized work-fluctuation theorem that applies for an arbitrary (out-of-equilibrium) initial state.
authors.affiliation: Yerevan Physics Institute, Alikhanian Brothers street 2, Yerevan 375036, Armenia.
authors.forename: A E
authors.initials: AE
authors.lastname: Allahverdyan
mesh_terms: D008962:Models, Theoretical; D011789:Quantum Theory; D013816:Thermodynamics; D013997:Time Factors