  We consider a quasi-static quantum Otto cycle using two effectively two-level
systems with degeneracy in the excited state. The systems are coupled through
isotropic exchange interaction of strength $J>0$, in the presence of an
external magnetic field $B$ which is varied during the cycle. We prove the
positive work condition, and show that level-degeneracy can act as a
thermodynamic resource, so that a larger amount of work can be extracted than
from the non-degenerate case, both with and without coupling. We also derive an
upper bound for the efficiency of the cycle. This bound is the same as derived
for a system of coupled spin-1/2 particles [G. Thomas and R. S. Johal, Phys.
Rev. E {\bf 83}, 031135 (2011)] i.e. without degeneracy, and depends only on
the control parameters of the Hamiltonian, but is independent of the level
degeneracy and the reservoir temperatures.
