Optical absorption spectra of finite systems from a conserving Bethe-Salpeter equation approach
Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
2 Institut für Physik, Martin-Luther-University, Halle-Wittenberg, Heinrich-Damerow-Strasse 4, 06120 Halle, Germany
3 Physics Department and Research Center OPTIMAS, University of Kaiserslautern, P.O. Box 3049, 67653 Kaiserslautern, Germany
Published online: 14 January 2011
We present a method for computing optical absorption spectra by means of a Bethe-Salpeter equation approach, which is based on a conserving linear response calculation for electron-hole coherences in the presence of an external electromagnetic field. This procedure allows, in principle, for the determination of the electron-hole correlation function self-consistently with the corresponding single-particle Green function. We analyze the general approach for a “one-shot” calculation of the photoabsorption cross section of finite systems, and discuss the importance of scattering and dephasing contributions in this approach. We apply the method to the closed-shell clusters Na4, Na and Na, treating one active electron per Na atom.
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2011