Regensburg 2007 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 5: Correlated Electrons - (General) Theory

TT 5.1: Hauptvortrag

Montag, 26. März 2007, 14:00–14:30, H18

Time-dependent density-functional theory: the framework, applications and recent developments — •Lucia Reining — LSI, CNRS-Ecole Polytechnique, Palaiseau, France

Time-Dependent Density Functional Theory (TDDFT) [1] is used with increasing success for the ab initio description of electronic excitations, measured for example in absorption, electron-energy loss or inelastic X-ray scattering spectroscopies. In fact, TDDFT correctly covers phenomena such as classical depolarization, the Fano effect due to interference of different excitations, or the appearance of bound exciton series in the bandgap of insulators. The description of these and many other interesting effects require of course different levels of approximation, for example concerning exchange-correlation effects.

This talk will give an overview of the spirit and the fundamental ingredients of TDDFT, in comparison to the alternative description of excitation spectra through the Bethe-Salpeter Equation [2]. Different contributions will be linked to physical effects that are observed in various applications [3] including simple bulk semiconductors and insulators, but also transition metal oxides, nanostructures, or disordered systems. Some recent developments will also be presented.

[1] E. Runge and E. K. U. Gross, Phys. Rev. Lett. 52, 997 (1984).

[2] G. Onida, L. Reining, and A. Rubio, Reviews of Modern Physics 74, 601 (2002).

[3] See e.g. F. Bruneval, S. Botti, L. Reining, Phys. Rev. Lett. 94, 219701 (2005); H.-C. Weissker et al., Phys. Rev. Lett. 97, 237602 (2006).