Abstract :
We derive the semiconductor Bloch equations for magnetoexcitons in real space. By means of the Laguerre-Fourier transform, an equivalent formulation can be given which uses Landau orbitals and plane waves as a basis set. The linear optical absorption is calculated using the real-space formulation. A transition is performed from a three-dimensional (zero magnetic field) to a one-dimensional (high magnetic field) semiconductor. A gap equation for a dense exciton gas is deduced, which contradicts previous results.