Dielectric breakdown of Mott insulators in dynamical mean-field theory

TL;DR

This paper investigates how Mott insulators respond to strong electric fields using nonequilibrium dynamical mean-field theory, revealing a stable quasistationary current state and a threshold behavior linked to the metal-insulator transition.

Contribution

It introduces a detailed analysis of dielectric breakdown in Mott insulators within a nonequilibrium DMFT framework, highlighting the formation of long-lived quasistationary states.

Findings

Stable quasistationary current states form after electric field application.

Threshold electric field for current onset depends on Coulomb interaction.

Threshold vanishes near the metal-insulator transition.

Abstract

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