  We study theoretically the full counting statistics of electron transport
through side-coupled double quantum dot (QD) based on an efficient
particle-number-resolved master equation. It is demonstrated that the
high-order cumulants of transport current are more sensitive to the quantum
coherence than the average current, which can be used to probe the quantum
coherence of the considered double QD system. Especially, the quantum coherence
plays a crucial role in determining whether the super-Poissonian noise occurs
in the weak inter-dot hopping coupling regime depending on the corresponding
dot-lead coupling, and the corresponding values of super-Poissonian noise can
be relatively enhanced when considering the spins of conduction electrons.
Moreover, this super-Poissonian noise bias range depends on the singly-occupied
eigenstates of the system, which thus suggests a tunable super-Poissonian noise
device. The occurrence-mechanism of super-Poissonian noise can be understood in
terms of the interplay of quantum coherence and effective competition between
fast-and-slow transport channels.
