  We consider quantum Hamiltonian systems composed of mutually interacting
"dynamical subsystem" with one or several degrees of freedom and "thermostat"
with arbitrary many degrees of freedom, under assumptions that the interaction
ensures irreversible behavior of the dynamical subsystem, that is finite
diffusivities of its coordinates in thermodynamically equilibrium state and
finite drift velocities and mobilities in non-equilibrium steady state in
presence of external driving forces. It is shown that, nevertheless, regardless
of characteristics of the interaction, the diffusivity and mobility have no
certain values but instead vary from one observation to another and undergo
1/f-type or flicker-type low-frequency fluctuations.
