  We propose a microscopic mechanism to resolve the long-standing puzzle of the
insulator-to-metal transition in correlated electronic systems, most notably
charge-density-wave (CDW) materials and Mott insulators, driven
far-from-equilibrium by a DC electric field. By introducing a generic model of
electrons coupled to an inelastic medium of phonons, we demonstrate that an
electron avalanche can occur in the bulk limit of such insulators at
arbitrarily small electric field. The quantum avalanche arises by the
generation of a ladder of in-gap states, created by a multi-phonon emission
process. Hot-phonons in the avalanche trigger a premature and partial collapse
of the correlated gap. The details of the phonon spectrum dictate two-stage
versus single-stage mechanisms which we associate with CDW and Mott resistive
transitions, respectively. The electron and phonon temperatures, as well as the
temperature dependence of the threshold fields, point to the quantum nature of
this nonequilibrium phase transition.

Strongly Correlated Electrons;Mesoscale and Nanoscale Physics