Self-cooling of a movable mirror to the ground state using radiation pressure

We show that one can cool a micromechanical oscillator to its quantum ground state using radiation pressure in an appropriately detuned cavity (self-cooling). From a theory based on Heisenberg-Langevin equations we find that optimal self-cooling occurs in the good cavity regime, when the cavity bandwidth is smaller than the mechanical frequency, but still larger than the effective mechanical damping. In this case the intracavity field and the vibrational mechanical mode coherently exchange their fluctuations, thus reducing the mirror temperature by several orders of magnitude. We also present dynamical calculations which show how to access the mirror temperature from a homodyne measurement of the fluctuations of the reflected field.