  The popular method of Nose and Hoover to create canonically distributed
positions and momenta in classical molecular dynamics simulations is
generalized to a genuine quantum system of infinite dimensionality. We show
that for the quantum harmonic oscillator, the equations of motion in terms of
coherent states can easily be modified in an analogous manner to mimic the
coupling of the system to a thermal bath and create a quantum canonical
ensemble. Possible applications to more complex systems, especially interacting
Fermion systems, are proposed.
