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Stationary coherence in small conducting arrays has been shown to influence
the transport efficiency of electronic nanodevices. Model schemes that capture
the interplay between electron delocalization and system-reservoir interactions
on the device performance are therefore important for designing next-generation
nanojunctions powered by quantum coherence. We use a Lindblad open quantum
system approach to obtain the current-voltage characteristics of small-size
networks of interacting conducting sites subject to radiative and non-radiative
interactions with the environment, for experimentally-relevant case studies.
Lindblad theory is shown to reproduce recent measurements of negative
conductance in single-molecule junctions using a biased two-site model driven
by thermal fluctuations. For array sites with conducting ground and excited
orbitals in the presence of radiative incoherent pumping, we show that Coulomb
interactions that otherwise suppress charge transport can be overcome to
produce light-induced currents. We also show that in nanojunctions having
asymmetric transfer rates between the array and electrical contacts, an
incoherent driving field can induce photocurrents at zero bias voltage whose
direction depend on the type or orbital delocalization established between
sites. Possible extensions of the theory are discussed.
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