  Cavity optomechanics provides a unique platform for controlling
micromechanical systems by means of optical fields that crosses the
classical-quantum boundary to achieve solid foundations for quantum
technologies. Currently, optomechanical resonators have become promising
candidates for the development of precisely controlled nano-motors,
ultrasensitive sensors and robust quantum information processors. For all these
applications, a crucial requirement is to cool the mechanical resonators down
to their quantum ground states. In this paper, we present a novel cooling
scheme to further cool a micromechanical resonator via the noise squeezing
effect. One quadrature in such a resonator can be squeezed to induce enhanced
fluctuation in the other, "heated" quadrature, which can then be used to cool
the mechanical motion via conventional optomechanical coupling. Our theoretical
analysis and numerical calculations demonstrate that this squeeze-and-cool
mechanism offers a quick technique for deeply cooling a macroscopic mechanical
resonator to an unprecedented temperature region below the zero-point
fluctuations.
