Dielectric breakdown of Mott insulators in dynamical mean-field theory

摘要

Using nonequilibrium dynamical mean-field theory, we compute the timeevolution of the current in a Mott insulator after a strong electric field isturned on. We observe the formation of a quasistationary state in which thecurrent is almost time-independent although the system is constantly excited.At moderately strong fields this state is stable for quite long times. Thestationary current exhibits a threshold behavior as a function of the field, inwhich the threshold increases with the Coulomb interaction and vanishes as themetal-insulator transition is approached.