  We introduce quantum heat engines that perform quantum Otto cycle and the
quantum Stirling cycle by using a coupled pair of harmonic oscillator as its
working substance. In the quantum regime, different working medium is
considered for the analysis of the engine models to boost the efficiency of the
cycles. In this work, we present Otto and Stirling cycle in the quantum realm
where the phase space is non-commutative in nature. By using the notion of
quantum thermodynamics we develop the thermodynamic variables in
non-commutative phase space. We encounter a catalytic effect (boost) on the
efficiency of the engine in non-commutative space (i.e, we encounter that the
Stirling cycle reaches near to the efficiency of the ideal cycle) when compared
with the commutative space. Moreover, we obtained a notion that the working
medium is much more effective for the analysis of the Stirling cycle than that
of the Otto cycle.
