Evidence of the Autoionizing Character of Biexcitons

Abstract

The highly structured profile of the ${\ensuremath{\Gamma}}_{1}$ biexciton level of CuCl is studied experimentally by resonant coherent nonlinear scattering. A theoretical model is presented which accurately describes the ${\ensuremath{\Gamma}}_{1}$ biexciton line shape in terms of a Fano interference, evidencing the autoionizing character of biexcitons.