  We theoretically prose and investigate a photo-Otto engine that is working
with a single-mode radiation field inside an optical cavity and alternatively
driven by a hot and a cold reservoir, where the hot reservoir is realized by
sending one of a pair of correlated two-level atoms to pass through the optical
cavity, and the cold one is made of a collection of noninteracting boson modes.
In terms of the quantum discord of the pair of atoms, we derive the analytical
expressions for the performance parameters (power and efficiency) and stability
measure (coefficient of variation for power). We show that quantum discord
boosts the performance and efficiency of the quantum engine, and even may
change the operation mode. We also demonstrate that quantum discord improves
the stability of machine by decreasing the coefficient of variation for power
which satisfies the generalized thermodynamic uncertainty relation. Finally, we
find that these results can be transferred to another photo-Otto engine model,
where the optical cavity is alternatively coupled to a hot thermal bosonic bath
and to a beam of pairs of the two correlated atoms that play the role of a cold
reservoir.
