  We study the optimal performance of an endoreversible quantum dot heat
engine, in which the heat transfer between the system and baths is mediated by
qubits, operating under the conditions of a trade-off objective function known
as maximum efficient power function defined by the product of power and
efficiency of the engine. First, we numerically study the optimization of the
efficient power function for the engine under consideration. Then, we obtain
some analytic results by applying hightemperature limit and compare the
performance of the engine at maximum efficient power functionto the engine
operating in the maximum power regime. We find that the engine operating at
maximum efficient power function produces at least 88.89% of the maximum power
output while at the same time reduces the power loss due to entropy production
by considerable amount. We conclude by studying the stochastic simulations of
the efficiency of the engine in maximum power and maximum efficient power
regime. We find that the engine operating at maximum power is subjected to less
power fluctuations as compared to the on one operating at maximum efficient
power function.
