Many-body perturbation theory using the density-functional concept: Beyond the GW approximation
|Title||Many-body perturbation theory using the density-functional concept: Beyond the GW approximation|
|Publication Type||Palaiseau Article|
|Author Address|| |
Bruneval, F (Reprint Author), Ecole Polytech, CNRS, CEA, UMR 7642,Lab Solides Irradies, F-91128 Palaiseau, France. Ecole Polytech, CNRS, CEA, UMR 7642,Lab Solides Irradies, F-91128 Palaiseau, France. Univ Roma Tor Vergata, Ist Nazl Fis Mat, I-00133 Rome, Italy. Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy.
|Bruneval, F, Sottile, F, Olevano, V, Del Sole, R, Reining, L|
|Year of Publication||2005|
|Journal||Phys. Rev. Lett.|
We propose an alternative formulation of many-body perturbation theory that uses the density-functional concept. Instead of the usual four-point integral equation for the polarizability, we obtain a two-point one, which leads to excellent optical absorption and energy-loss spectra. The corresponding three-point vertex function and self-energy are then simply calculated via an integration, for any level of approximation. Moreover, we show the direct impact of this formulation on the time-dependent density-functional theory. Numerical results for the band gap of bulk silicon and solid argon illustrate corrections beyond the GW approximation for the self-energy.