Nonequilibrium dual-boson approach*

We develop nonequilibrium auxiliary quantum master equation dual boson method (aux-DB),
and argue that it presents a convenient way to describe steady states of correlated impurity models
(such as single molecule optoelectronic devices) where electron and energy transport should be taken
into account. The aux-DB is shown to provide high accuracy with relatively low numerical cost.
Theoretical analysis is followed by illustrative simulations within generic two-level junction model,
where the new scheme is benchmarked against numerically exact results.