Regensburg 2010 – wissenschaftliches Programm
HL 60.3: Poster
Donnerstag, 25. März 2010, 18:00–20:00, Poster D1
Degree of ionization and excitonic BEC window in Cu2O and ZnSe — •Felix Richter, Dirk Semkat, Günter Manzke, Dietrich Kremp, and Klaus Henneberger — Institut für Physik, Universität Rostock, 18051 Rostock
We evaluate the ionization equilibrium in the high-density electron–hole plasma of Cu2O and ZnSe. The influence of many-particle effects on the chemical potentials of carriers, the exitonic binding energy, and the Mott transition (density ionization) is investigated over a wide range of temperatures and carrier densities. In contrast to simplifying approximations used in the literature we consider full dynamical screening between carriers and find the Mott transition to occur at densities more than one order of magnitude higher than estimated before.
The results are given as a phase diagram of the ionization. Special attention is directed to the determination of the region where an excitonic fraction can reach the critical density and, therefore, Bose–Einstein condensation can occur.
 D. Semkat, F. Richter, D. Kremp, G. Manzke, W.-D. Kraeft, and K. Henneberger, Phys. Rev. B 80, 155201 (2009)  F. Richter, D. Semkat, D. Kremp, and K. Henneberger, Phys. Status Solidi C 6, 532 (2009)  G. Manzke, D. Semkat, F. Richter, D. Kremp, and K. Henneberger, submitted for publication (2009)