Coexistence of excited polarons and metastable delocalized states in photoinduced metals

Using a nonequilibrium dynamical mean-field theory the authors study relaxation of a hot-electron distribution coupled to optical phonons. Their main interest is in the adiabatic regime of phonon frequencies smaller than the electronic bandwidth and in an extended analysis of photoemission spectra. In this limit initial coherent phonon oscillations become strongly damped, leaving the system in a mixture of excited polaron states and metastable delocalized states.