  Employing the stochastic wave function method, we study quantum features of
stochastic entropy production in nonequilibrium processes of open systems. It
is demonstarted that continuous measurements on the environment introduce an
additional, non-thermal contribution to the entropy flux, which is shown to be
a direct consequence of quantum fluctuations. These features lead to a quantum
definition of single trajectory entropy contributions, which accounts for the
difference between classical and quantum trajectories and results in a quantum
correction to the standard form of the integral fluctuation theorem.
