Spectral moment sum rules for strongly correlated electrons in time-dependent electric fields

Spectral moment sum rules for strongly correlated electrons in time-dependent electric fields

We derive exact operator average expressions for the first two spectral moments of nonequilibrium Green’s functions for the Falicov-Kimball model and the Hubbard model in the presence of a spatially uniform, time-dependent electric field. The moments are similar to the well-known moments in equilibrium, but we extend those results to systems in arbitrary time-dependent electric fields. Moment s...

Inhomogeneous spectral moment sum rules for the retarded Green function and self-energy of strongly correlated electrons or ultracold fermionic atoms in optical lattices

Spectral moment sum rules are presented for the inhomogeneous many-body problem described by the fermionic Falicov-Kimball or Hubbard models. These local sum rules allow for arbitrary hoppings, site energies, and interactions. They can be employed to quantify the accuracy of numerical solutions to the inhomogeneous many-body problem such as strongly correlated multilayered devices, ultracold at...

Nonequilibrium sum rules for the retarded self-energy of strongly correlated electrons

We derive the first two moment sum rules of the conduction electron retarded self-energy for both the Falicov–Kimball model and the Hubbard model coupled to an external spatially uniform and time-dependent electric field this derivation also extends the known nonequilibrium moment sum rules for the Green functions to the third moment . These sum rules are used to further test the accuracy of no...

Strongly correlated electrons

Strongly Correlated Electrons in Solids

Most emergent properties of the materials discovered since the 1980s are related to the existence of electronelectron interactions which are large with respect to the kinetic energies and could not be thoroughly studied before. The occurrence of metal insulator transitions, of exotic magnetic and/or superconducting properties in many new compounds have stimulated a large series of experimental ...