  Lipkin-Meshkov-Glick model of two anisotropically interacting spins in a
magnetic field is proposed as a working substance of a quantum Otto engine to
explore and exploit the anisotropy effects for the optimization of engine
operation. Three different cases for the adiabatic branches of the cycle have
been considered. In the first two cases, either the magnetic field or coupling
strength are changed; while in the third case, both the magnetic field and the
coupling strength are changed by the same ratio. The system parameters for
which the engine can operate similar to or dramatically different from the
engines of non-interacting spins or of coupled spins with Ising model or
isotropic XY model interactions are determined. In particular, the role of
anisotropy to enhance cooperative work, and to optimize maximum work with high
efficiency, as well as to operate the engine near the Carnot bound are
revealed.
