Physical review. B, Condensed matter
Polarization choices in exciton-biexciton system of GaAs quantum wells
S. Adachi, T. Miyashita, S. Takeyama, Y. Takagi, Atsushi Tackeuchi, Masaaki Nakayama
Abstract
We study the induced absorption due to biexciton formation in absorption bleaching pump-probe signals and the quantum beats between exciton and biexciton in the four-wave-mixing signals. The origin is confirmed by the polarization dependence of the signals in both experiments. The definite discrimination between exciton-biexciton quantum beats and the others by the polarization choices is demonstrated clearly. We also show the well-width dependence of the biexciton binding energy that is determined by the period of the quantum beats in the range of well width 45--150 \AA{} of GaAs/${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As (x=0.3--1.0) multiple quantum wells.