  The Stokes and anti-Stokes components of the spectrum of resonance
fluorescence of a single trapped atom, which originate from the mechanical
coupling between the scattered photons and the quantized motion of the atomic
center of mass, exhibit quantum correlations which are of two-mode-squeezing
type. We study and demonstrate the build-up of such correlations in a specific
setup, which is experimentally accessible, and where the atom acts as efficient
and continuous source of EPR-entangled, two-mode squeezed light.
