  Coherent interconversion between optical and mechanical excitations in an
optomechanical cavity can be used to engineer a quantum heat engine. This heat
engine is based on an Otto cycle between a cold photonic reservoir and a hot
phononic reservoir [Phys. Rev. Lett. 112, 150602 (2014)]. Building on our
previous work, we (i) develop a detailed theoretical analysis of the work and
the efficiency of the engine, and (ii) perform an investigation of the quantum
thermodynamics underlying this scheme. In particular, we analyze the
thermodynamic performance in both the dressed polariton picture and the
original bare photon and phonon picture. Finally, (iii) a numerical simulation
is performed to derive the full evolution of the quantum optomechanical system
during the Otto cycle, by taking into account all relevant sources of noise.

Quantum Physics