  Following a recent work (briefly reviewed below) we consider temporal
fluctuations in the reduced density matrix elements for a coupled system
involving a pair of kicked rotors as also one made up of a pair of Harper
Hamiltonians. These dynamical fluctuations are found to constitute a reliable
indicator of the degree of chaos in the quantum dynamics, and are related to
stationary features like the eigenvalue and eigenvector distributions of the
system under consideration. A brief comparison is made with the evolution of
the reduced distribution function in the classical phase space.
