  A key insight from recent studies is that noise, such as dephasing, can
improve the efficiency of quantum transport by suppressing coherent
single-particle interference effects. However, it is not yet clear whether
dephasing can enhance transport in an interacting many-body system. Here, we
address this question by analyzing the transport properties of a boundary
driven spinless fermion chain with nearest-neighbor interactions subject to
bulk dephasing. The many-body nonequilibrium stationary state is determined
using large-scale matrix product simulations of the corresponding quantum
master equation. We find dephasing enhanced transport only in the strongly
interacting regime, where it is shown to induce incoherent transitions bridging
the gap between bound dark states and bands of mobile eigenstates. The generic
nature of the transport enhancement is illustrated by a simple toy model, which
contains the basic elements required for its emergence. Surprisingly, the
effect is significant even in the linear response regime of the full system,
and it is predicted to exist for any large and finite chain. The response of
the system to dephasing also establishes a signature of an underlying
nonequilibrium phase transition between regimes of transport degradation and
enhancement. The existence of this transition is shown not to depend on the
integrability of the model considered. As a result, dephasing enhanced
transport is expected to persist in more realistic nonequilibrium strongly
correlated systems.
