Faraday rotation in multiple quantum wells of GaAs/AlGaAs

We report on the results of first measurements of the Faraday rotation of modulated n-doped multiple quantum wells of GaAs/AlxGa1-xAs (x = 0.312). The measurements have been performed in the magnetic fields up to 13 T at the temperature of 2 K, in the spectral region of interband transitions. A rich structure of magneto-excitons has been found in the measured spectra. Faraday rotation (phase) measurements are proposed as an alternative method to photoluminescence excitation for investigations of magneto-excitons in quantum wells. The dependence of the measured Faraday rotation on magnetic field and hypothetical connections with quantum Hall effect are also discussed.