  A quantum engine with n qubits performing thermodynamic cycles with two
thermal reservoirs is presented. While such constructions have been aplenty,
here we show the existence of what we term as "limit cycle" at a purely quantum
level of description owing to the properties of superoperators governing the
evolution of states. It is shown that the limit cycle is the same under forward
and reverse protocol of cycle operations. This limit cycle becomes the basis of
the quantum engine. One dimensional Ising model has been used to illustrate
these ideas.
