# Dresden 2014 – wissenschaftliches Programm

## Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

# HL: Fachverband Halbleiterphysik

## HL 64: Frontiers of electronic structure theory - Non-equilibrium phenomena at the nano-scale IV (organized by O)

### HL 64.3: Vortrag

### Mittwoch, 2. April 2014, 11:15–11:30, TRE Ma

**Optimized effective potential approach to time-dependent density functional theory for many-electron systems interacting with cavity photons** — •Camilla Pellegrini^{1}, Johannes Flick^{2}, Heiko Appel^{2}, Ilya V. Tokatly^{1,3}, and Angel Rubio^{1,2} — ^{1}Nano-bio Spectroscopy Group and ETSF Scientific Development Centre, Departamento de Física de Materiales, Universidad del País Vasco UPV/EHU, E-20018 San Sebastían, Spain — ^{2}Fritz-Haber Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany — ^{3}IKERBASQUE, Bilbao, Spain

In a recent paper [1] time dependent density functional theory has been generalized to many-electron systems strongly coupled to quantum electromagnetic modes of a microcavity. Here we construct an approximation for the corresponding exchange-correlation (xc) potential by extending the optimized effective potential (OEP) method to the electron-photon system. The derivation of the OEP equation employing the non-equilibrium Green's function formalism, and the first order approximation for the electronic self-energy is presented. Beyond the mean field level, the electron-photon coupling generates a time non-local photon-mediated interaction between the electrons, whose propagator enters the exchange-like diagram. We further show the approximated xc-potential for a model two-level diatomic molecule with one electron coupled to photon modes. The comparison between the obtained results and the exact numerical ones in the different coupling regimes (from weak up to ultra-strong) is discussed. [1] I.V. Tokatly, Phys. Rev. Lett. 110, 233001(2013)