Dresden 2017 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 24: Electronic-Structure Theory: New Concepts and Developments in Density Functional Theory and Beyond - II
HL 24.6: Vortrag
Montag, 20. März 2017, 16:30–16:45, GER 38
Dynamic LDA for electronic excitations — •Marco Vanzini1,2, Matteo Gatti1,2,3, and Lucia Reining1,2 — 1Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA, Université Paris-Saclay, 91128 Palaiseau, France — 2European Theoretical Spectroscopy Facility (ETSF) — 3Synchrotron SOLEIL, L’Orme des Merisiers, BP 48 Saint-Aubin, 91192 Gif sur Yvette, France
Density Functional Theory is an extremely useful tool for dealing with ground state properties such as the density or total energy. Kohn–Sham eigenvalues are often considered as approximated electronic excitations, but the resulting spectra are poor.
We propose a generalization of the Kohn–Sham approach to address in an exact framework electron addition and removal spectra. They can be measured by photoemission experiments, and can be evaluated using a computationally expensive non–local Self Energy. Our method is instead based on a frequency–dependent local potential [1], which significantly reduces the computing time of an ab–initio calculation.
To find this spectral potential in practice, we propose a jellium–based dynamical local density approximation (dynLDA): it relates the unknown potential to its homogeneous counterpart, via a non–trivial connector in space and frequency, which is based on physical insight.
In this talk, I will discuss the achievements and the limits of dynLDA, using models and real solids.
[1] M. Gatti et al., Phys. Rev. Lett. 99, 057401 (2007).