  In this work, we explore the possibility of emergent nonequilibrium steady
states arising from the electric-field-driven Mott insulator via the
Keldysh-Floquet dynamical mean field theory (DMFT), which can determine the
fully-interacting, nonequilibrium steady-state Green's functions with the
noninteracting counterparts as an input to the DMFT self-consistency loop.
Unlike the retarded component, obtaining the lesser Green's function for the
noninteracting system presents an important obstacle since the thermalization
of the noninteracting system still requires a precise understanding of the
dissipation mechanism. A crucial breakthrough in this work is that the
noninteracting lesser Green's function can be determined in terms of the
Wannier-Stark ladder (WSL) eigenstates, which are thermalized via the standard
canonical ensemble according to the Markovian quantum master equation. As a
result, it is shown that the intricate interplay between strong correlation and
large electric field can generate a sequence of two dielectric breakdowns with
the first induced by a coherent reconstruction of the mid-gap state within the
Mott gap and the second by an incoherent tunneling through the biased Hubbard
bands. It is predicted that the reconstructed mid-gap state generates its own
emergent WSL structure with a reduced effective electric field. The two
dielectric breakdowns are mediated by a reentrant insulating phase, which is
characterized by the population inversion, causing instability toward
inhomogeneous current density states at weak electron-impurity scattering.
