  By using quantum mechanical effects, quantum computers promise significant
speedups in solving problems intractable for conventional computers. However,
despite recent progress they remain limited in scaling and availability-making
quantum software and hardware development heavily reliant on quantum simulators
running on conventional hardware. However, most of those simulators mimic
perfect quantum computers and, hence, ignore the fragile nature of quantum
mechanical effects which frequently yield to decoherence errors in real quantum
devices. Considering those errors during the simulation is complex, but
necessary in order to tailor quantum algorithms for specific devices. Thus far,
most state-of-the-art simulators considering decoherence errors rely on
(exponentially) large array representations. As an alternative, simulators
based on decision diagrams have been shown very promising for simulation of
quantum circuits in general, but have not supported decoherence errors yet. In
this work, we are closing this gap. We investigate how the consideration of
decoherence errors affects the simulation performance of approaches based on
decision diagrams and propose advanced solutions to mitigate negative effects.
Experiments confirm that this yields improvements of several orders of
magnitudes compared to a naive consideration of errors.
