  We propose and analyze a microscopic Stirling heat engine based on an
optomechanical system. The working fluid is a single vibrational mode of a
mechanical resonator, which interacts by radiation pressure with a
feedback-controlled optical cavity. The cavity light is used to engineer the
thermal reservoirs and to steer the resonator through a thermodynamic cycle. In
particular, the feedback is used to properly modulate the light fluctuations
inside the cavity and hence to realize efficient thermodynamic transformations
with realistic optomechanical devices.
