Fano resonances due to coupled magnetoexciton and continuum states in bulk semiconductors

We have observed Fano resonances in linear absorption experiments on GaAs under a magnetic field. In a bulk semiconductor in a magnetic field, Fano interference is the result of the coupling of higher-order magnetoexcitons and energetically degenerate one-dimensional continuum states. We show that these experimental findings can be described by the model of a two-band semiconductor in the effective-mass approximation. Numerical calculations of the linear magnetoabsorption are presented that demonstrate that the coupling between magnetoexcitons and continuum states is due to Coulomb interaction.