Nonlinear absorption of two-dimensional magnetoexcitons in InxGa1xAs/InyAl1yAs quantum wells

Abstract
Applying a perpendicular magnetic field to a semiconductor quantum well results in a transition from a two-dimensional into a zero-dimensional system. The mutual interaction of the magnetoexciton levels is studied by populating the 1s magnetoexciton under steady-state conditions and measuring the related changes in absorption. We find redshifts of all energetically higher magnetoexcitons and a blueshift of the 1s exciton due to repulsive exciton-exciton interaction. The experimental results are compared with solutions of the semiconductor Bloch equations. Good qualitative agreement is found.