Steady-State Nonequilibrium Density of States of Driven Strongly Correlated Lattice Models in Infinite Dimensions

An exact formalism for calculating the retarded and advanced Green’s functions of strongly correlated lattice models in a uniform electric field is derived within dynamical mean-field theory. To illustrate the method, we solve for the nonequilibrium density of states of the Hubbard model in both the metallic and Mott-insulating phases at half-filling (with an arbitrary strength electric field) by employing the approximate numerical renormalization group as the impurity solver. This general approach can be applied to any strongly correlated lattice model in the limit of large dimensions.

Figure 1

Density of states for the infinite-dimensional Hubbard model with $E=0.5$. The panels run from systems that are metallic to insulating (when in equilibrium): (a) $U=0.5$; (b) $U=2$; (c) $U=4$; and (d) $U=8$. Note the change in the vertical axis size for the different panels.

Figure 2

Density of states for the infinite-dimensional Hubbard model with $E=4$. The panels run from systems that are metallic to insulating (when in equilibrium): (a) $U=0.5$; (b) $U=2$; (c) $U=4$; and (d) $U=8$. Note the change in the vertical axis size for the different panels.